Merge branch 'en/merge-recursive-debug'

Remove remnants of the recursive merge strategy backend, which was
superseded by the ort merge strategy.

* en/merge-recursive-debug:
  builtin/{merge,rebase,revert}: remove GIT_TEST_MERGE_ALGORITHM
  tests: remove GIT_TEST_MERGE_ALGORITHM and test_expect_merge_algorithm
  merge-recursive.[ch]: thoroughly debug these
  merge, sequencer: switch recursive merges over to ort
  sequencer: switch non-recursive merges over to ort
  merge-ort: enable diff-algorithms other than histogram
  builtin/merge-recursive: switch to using merge_ort_generic()
  checkout: replace merge_trees() with merge_ort_nonrecursive()

Documentation/merge-strategies.adoc

@@ -87,6 +87,20 @@ no-renames;;
 	configuration variable.
 	See also linkgit:git-diff[1] `--no-renames`.
 
+histogram;;
+	Deprecated synonym for `diff-algorithm=histogram`.
+
+patience;;
+	Deprecated synonym for `diff-algorithm=patience`.
+
+diff-algorithm=[histogram|minimal|myers|patience];;
+	Use a different diff algorithm while merging, which can help
+	avoid mismerges that occur due to unimportant matching lines
+	(such as braces from distinct functions).  See also
+	linkgit:git-diff[1] `--diff-algorithm`.  Note that `ort`
+	defaults to `diff-algorithm=histogram`, while regular diffs
+	currently default to the `diff.algorithm` config setting.
+
 subtree[=<path>];;
 	This option is a more advanced form of 'subtree' strategy, where
 	the strategy makes a guess on how two trees must be shifted to
@@ -95,36 +109,11 @@ subtree[=<path>];;
 	two trees to match.
 
 recursive::
-	This can only resolve two heads using a 3-way merge
+	This is now a synonym for `ort`.  It was an alternative
-	algorithm.  When there is more than one common
+	implementation until v2.49.0, but was redirected to mean `ort`
-	ancestor that can be used for 3-way merge, it creates a
+	in v2.50.0.  The previous recursive strategy was the default
-	merged tree of the common ancestors and uses that as
+	strategy for resolving two heads from Git v0.99.9k until
-	the reference tree for the 3-way merge.  This has been
+	v2.33.0.
-	reported to result in fewer merge conflicts without
-	causing mismerges by tests done on actual merge commits
-	taken from Linux 2.6 kernel development history.
-	Additionally this can detect and handle merges involving
-	renames.  It does not make use of detected copies.  This was
-	the default strategy for resolving two heads from Git v0.99.9k
-	until v2.33.0.
-+
-For a path that is a submodule, the same caution as 'ort' applies to this
-strategy.
-+
-The 'recursive' strategy takes the same options as 'ort'.  However,
-there are two additional options that 'ort' ignores (not documented
-above) that are potentially useful with the 'recursive' strategy:
-
-patience;;
-	Deprecated synonym for `diff-algorithm=patience`.
-
-diff-algorithm=[patience|minimal|histogram|myers];;
-	Use a different diff algorithm while merging, which can help
-	avoid mismerges that occur due to unimportant matching lines
-	(such as braces from distinct functions).  See also
-	linkgit:git-diff[1] `--diff-algorithm`.  Note that `ort`
-	specifically uses `diff-algorithm=histogram`, while `recursive`
-	defaults to the `diff.algorithm` config setting.
 
 resolve::
 	This can only resolve two heads (i.e. the current branch
@@ -145,7 +134,7 @@ ours::
 	ignoring all changes from all other branches.  It is meant to
 	be used to supersede old development history of side
 	branches.  Note that this is different from the -Xours option to
-	the 'recursive' merge strategy.
+	the 'ort' merge strategy.
 
 subtree::
 	This is a modified `ort` strategy. When merging trees A and

Documentation/technical/sparse-checkout.adoc

@@ -356,8 +356,6 @@ understanding these differences can be beneficial.
     The behavior for these commands somewhat depends upon the merge
     strategy being used:
       * `ort` behaves as described above
-      * `recursive` tries to not vivify files unnecessarily, but does sometimes
-	vivify files without conflicts.
       * `octopus` and `resolve` will always vivify any file changed in the merge
 	relative to the first parent, which is rather suboptimal.
 

Makefile

@@ -1070,7 +1070,6 @@ LIB_OBJS += merge-blobs.o
 LIB_OBJS += merge-ll.o
 LIB_OBJS += merge-ort.o
 LIB_OBJS += merge-ort-wrappers.o
-LIB_OBJS += merge-recursive.o
 LIB_OBJS += merge.o
 LIB_OBJS += midx.o
 LIB_OBJS += midx-write.o

builtin/checkout.c

@@ -17,7 +17,7 @@
 #include "merge-ll.h"
 #include "lockfile.h"
 #include "mem-pool.h"
-#include "merge-recursive.h"
+#include "merge-ort-wrappers.h"
 #include "object-name.h"
 #include "object-store-ll.h"
 #include "parse-options.h"
@@ -907,10 +907,10 @@ static int merge_working_tree(const struct checkout_opts *opts,
 			o.branch1 = new_branch_info->name;
 			o.branch2 = "local";
 			o.conflict_style = opts->conflict_style;
-			ret = merge_trees(&o,
+			ret = merge_ort_nonrecursive(&o,
-					  new_tree,
+						     new_tree,
-					  work,
+						     work,
-					  old_tree);
+						     old_tree);
 			if (ret < 0)
 				exit(128);
 			ret = reset_tree(new_tree,

builtin/merge-recursive.c

@@ -3,7 +3,7 @@
 #include "advice.h"
 #include "gettext.h"
 #include "hash.h"
-#include "merge-recursive.h"
+#include "merge-ort-wrappers.h"
 #include "object-name.h"
 
 static const char builtin_merge_recursive_usage[] =
@@ -89,7 +89,7 @@ int cmd_merge_recursive(int argc,
 	if (o.verbosity >= 3)
 		printf(_("Merging %s with %s\n"), o.branch1, o.branch2);
 
-	failed = merge_recursive_generic(&o, &h1, &h2, bases_count, bases, &result);
+	failed = merge_ort_generic(&o, &h1, &h2, bases_count, bases, &result);
 
 	free(better1);
 	free(better2);

builtin/merge.c

@@ -39,7 +39,6 @@
 #include "rerere.h"
 #include "help.h"
 #include "merge.h"
-#include "merge-recursive.h"
 #include "merge-ort-wrappers.h"
 #include "resolve-undo.h"
 #include "remote.h"
@@ -171,7 +170,7 @@ static struct strategy *get_strategy(const char *name)
 	struct strategy *ret;
 	static struct cmdnames main_cmds = {0}, other_cmds = {0};
 	static int loaded;
-	char *default_strategy = getenv("GIT_TEST_MERGE_ALGORITHM");
+	char *default_strategy = NULL;
 
 	if (!name)
 		return NULL;
@@ -750,12 +749,8 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 
 		repo_hold_locked_index(the_repository, &lock,
 				       LOCK_DIE_ON_ERROR);
-		if (!strcmp(strategy, "ort"))
+		clean = merge_ort_recursive(&o, head, remoteheads->item,
-			clean = merge_ort_recursive(&o, head, remoteheads->item,
+					    reversed, &result);
-						    reversed, &result);
-		else
-			clean = merge_recursive(&o, head, remoteheads->item,
-						reversed, &result);
 		free_commit_list(reversed);
 		strbuf_release(&o.obuf);
 
@@ -1316,12 +1311,6 @@ int cmd_merge(int argc,
 	if (branch)
 		skip_prefix(branch, "refs/heads/", &branch);
 
-	if (!pull_twohead) {
-		char *default_strategy = getenv("GIT_TEST_MERGE_ALGORITHM");
-		if (default_strategy && !strcmp(default_strategy, "ort"))
-			pull_twohead = xstrdup("ort");
-	}
-
 	init_diff_ui_defaults();
 	git_config(git_merge_config, NULL);
 
@@ -1522,12 +1511,6 @@ int cmd_merge(int argc,
 			fast_forward = FF_NO;
 	}
 
-	if (!use_strategies && !pull_twohead &&
-	    remoteheads && !remoteheads->next) {
-		char *default_strategy = getenv("GIT_TEST_MERGE_ALGORITHM");
-		if (default_strategy)
-			append_strategy(get_strategy(default_strategy));
-	}
 	if (!use_strategies) {
 		if (!remoteheads)
 			; /* already up-to-date */

builtin/rebase.c

@@ -1575,11 +1575,6 @@ int cmd_rebase(int argc,
 			    options.default_backend);
 	}
 
-	if (options.type == REBASE_MERGE &&
-	    !options.strategy &&
-	    getenv("GIT_TEST_MERGE_ALGORITHM"))
-		options.strategy = xstrdup(getenv("GIT_TEST_MERGE_ALGORITHM"));
-
 	switch (options.type) {
 	case REBASE_MERGE:
 		options.state_dir = merge_dir();

builtin/revert.c

@@ -252,8 +252,6 @@ static int run_sequencer(int argc, const char **argv, const char *prefix,
 		free(opts->strategy);
 		opts->strategy = xstrdup_or_null(strategy);
 	}
-	if (!opts->strategy && getenv("GIT_TEST_MERGE_ALGORITHM"))
-		opts->strategy = xstrdup(getenv("GIT_TEST_MERGE_ALGORITHM"));
 	free(options);
 
 	if (cmd == 'q') {

ci/run-build-and-tests.sh

@@ -20,7 +20,6 @@ linux-breaking-changes)
 linux-TEST-vars)
 	export OPENSSL_SHA1_UNSAFE=YesPlease
 	export GIT_TEST_SPLIT_INDEX=yes
-	export GIT_TEST_MERGE_ALGORITHM=recursive
 	export GIT_TEST_FULL_IN_PACK_ARRAY=true
 	export GIT_TEST_OE_SIZE=10
 	export GIT_TEST_OE_DELTA_SIZE=5

merge-ort-wrappers.h

@@ -1,7 +1,7 @@
 #ifndef MERGE_ORT_WRAPPERS_H
 #define MERGE_ORT_WRAPPERS_H
 
-#include "merge-recursive.h"
+#include "merge-ort.h"
 
 /*
  * rename-detecting three-way merge, no recursion.

merge-ort.c

@@ -26,6 +26,7 @@
 #include "cache-tree.h"
 #include "commit.h"
 #include "commit-reach.h"
+#include "config.h"
 #include "diff.h"
 #include "diffcore.h"
 #include "dir.h"
@@ -4957,9 +4958,6 @@ static void merge_start(struct merge_options *opt, struct merge_result *result)
 	}
 	trace2_region_leave("merge", "sanity checks", opt->repo);
 
-	/* Default to histogram diff.  Actually, just hardcode it...for now. */
-	opt->xdl_opts = DIFF_WITH_ALG(opt, HISTOGRAM_DIFF);
-
 	/* Handle attr direction stuff for renormalization */
 	if (opt->renormalize)
 		git_attr_set_direction(GIT_ATTR_CHECKOUT);
@@ -5325,3 +5323,161 @@ void merge_incore_recursive(struct merge_options *opt,
 	merge_ort_internal(opt, merge_bases, side1, side2, result);
 	trace2_region_leave("merge", "incore_recursive", opt->repo);
 }
+
+static void merge_recursive_config(struct merge_options *opt, int ui)
+{
+	char *value = NULL;
+	int renormalize = 0;
+	git_config_get_int("merge.verbosity", &opt->verbosity);
+	git_config_get_int("diff.renamelimit", &opt->rename_limit);
+	git_config_get_int("merge.renamelimit", &opt->rename_limit);
+	git_config_get_bool("merge.renormalize", &renormalize);
+	opt->renormalize = renormalize;
+	if (!git_config_get_string("diff.renames", &value)) {
+		opt->detect_renames = git_config_rename("diff.renames", value);
+		free(value);
+	}
+	if (!git_config_get_string("merge.renames", &value)) {
+		opt->detect_renames = git_config_rename("merge.renames", value);
+		free(value);
+	}
+	if (!git_config_get_string("merge.directoryrenames", &value)) {
+		int boolval = git_parse_maybe_bool(value);
+		if (0 <= boolval) {
+			opt->detect_directory_renames = boolval ?
+				MERGE_DIRECTORY_RENAMES_TRUE :
+				MERGE_DIRECTORY_RENAMES_NONE;
+		} else if (!strcasecmp(value, "conflict")) {
+			opt->detect_directory_renames =
+				MERGE_DIRECTORY_RENAMES_CONFLICT;
+		} /* avoid erroring on values from future versions of git */
+		free(value);
+	}
+	if (ui) {
+		if (!git_config_get_string("diff.algorithm", &value)) {
+			long diff_algorithm = parse_algorithm_value(value);
+			if (diff_algorithm < 0)
+				die(_("unknown value for config '%s': %s"), "diff.algorithm", value);
+			opt->xdl_opts = (opt->xdl_opts & ~XDF_DIFF_ALGORITHM_MASK) | diff_algorithm;
+			free(value);
+		}
+	}
+	git_config(git_xmerge_config, NULL);
+}
+
+static void init_merge_options(struct merge_options *opt,
+			struct repository *repo, int ui)
+{
+	const char *merge_verbosity;
+	memset(opt, 0, sizeof(struct merge_options));
+
+	opt->repo = repo;
+
+	opt->detect_renames = -1;
+	opt->detect_directory_renames = MERGE_DIRECTORY_RENAMES_CONFLICT;
+	opt->rename_limit = -1;
+
+	opt->verbosity = 2;
+	opt->buffer_output = 1;
+	strbuf_init(&opt->obuf, 0);
+
+	opt->renormalize = 0;
+
+	opt->conflict_style = -1;
+	opt->xdl_opts = DIFF_WITH_ALG(opt, HISTOGRAM_DIFF);
+
+	merge_recursive_config(opt, ui);
+	merge_verbosity = getenv("GIT_MERGE_VERBOSITY");
+	if (merge_verbosity)
+		opt->verbosity = strtol(merge_verbosity, NULL, 10);
+	if (opt->verbosity >= 5)
+		opt->buffer_output = 0;
+}
+
+void init_ui_merge_options(struct merge_options *opt,
+			struct repository *repo)
+{
+	init_merge_options(opt, repo, 1);
+}
+
+void init_basic_merge_options(struct merge_options *opt,
+			struct repository *repo)
+{
+	init_merge_options(opt, repo, 0);
+}
+
+/*
+ * For now, members of merge_options do not need deep copying, but
+ * it may change in the future, in which case we would need to update
+ * this, and also make a matching change to clear_merge_options() to
+ * release the resources held by a copied instance.
+ */
+void copy_merge_options(struct merge_options *dst, struct merge_options *src)
+{
+	*dst = *src;
+}
+
+void clear_merge_options(struct merge_options *opt UNUSED)
+{
+	; /* no-op as our copy is shallow right now */
+}
+
+int parse_merge_opt(struct merge_options *opt, const char *s)
+{
+	const char *arg;
+
+	if (!s || !*s)
+		return -1;
+	if (!strcmp(s, "ours"))
+		opt->recursive_variant = MERGE_VARIANT_OURS;
+	else if (!strcmp(s, "theirs"))
+		opt->recursive_variant = MERGE_VARIANT_THEIRS;
+	else if (!strcmp(s, "subtree"))
+		opt->subtree_shift = "";
+	else if (skip_prefix(s, "subtree=", &arg))
+		opt->subtree_shift = arg;
+	else if (!strcmp(s, "patience"))
+		opt->xdl_opts = DIFF_WITH_ALG(opt, PATIENCE_DIFF);
+	else if (!strcmp(s, "histogram"))
+		opt->xdl_opts = DIFF_WITH_ALG(opt, HISTOGRAM_DIFF);
+	else if (skip_prefix(s, "diff-algorithm=", &arg)) {
+		long value = parse_algorithm_value(arg);
+		if (value < 0)
+			return -1;
+		/* clear out previous settings */
+		DIFF_XDL_CLR(opt, NEED_MINIMAL);
+		opt->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
+		opt->xdl_opts |= value;
+	}
+	else if (!strcmp(s, "ignore-space-change"))
+		DIFF_XDL_SET(opt, IGNORE_WHITESPACE_CHANGE);
+	else if (!strcmp(s, "ignore-all-space"))
+		DIFF_XDL_SET(opt, IGNORE_WHITESPACE);
+	else if (!strcmp(s, "ignore-space-at-eol"))
+		DIFF_XDL_SET(opt, IGNORE_WHITESPACE_AT_EOL);
+	else if (!strcmp(s, "ignore-cr-at-eol"))
+		DIFF_XDL_SET(opt, IGNORE_CR_AT_EOL);
+	else if (!strcmp(s, "renormalize"))
+		opt->renormalize = 1;
+	else if (!strcmp(s, "no-renormalize"))
+		opt->renormalize = 0;
+	else if (!strcmp(s, "no-renames"))
+		opt->detect_renames = 0;
+	else if (!strcmp(s, "find-renames")) {
+		opt->detect_renames = 1;
+		opt->rename_score = 0;
+	}
+	else if (skip_prefix(s, "find-renames=", &arg) ||
+		 skip_prefix(s, "rename-threshold=", &arg)) {
+		if ((opt->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0)
+			return -1;
+		opt->detect_renames = 1;
+	}
+	/*
+	 * Please update $__git_merge_strategy_options in
+	 * git-completion.bash when you add new options
+	 */
+	else
+		return -1;
+	return 0;
+}

merge-ort.h

@@ -1,10 +1,11 @@
 #ifndef MERGE_ORT_H
 #define MERGE_ORT_H
 
-#include "merge-recursive.h"
 #include "hash.h"
+#include "strbuf.h"
 
 struct commit;
+struct commit_list;
 struct tree;
 struct strmap;
 
@@ -44,6 +45,51 @@ struct merge_result {
 	unsigned _properly_initialized;
 };
 
+struct merge_options_internal;
+struct merge_options {
+	struct repository *repo;
+
+	/* ref names used in console messages and conflict markers */
+	const char *ancestor;
+	const char *branch1;
+	const char *branch2;
+
+	/* rename related options */
+	int detect_renames;
+	enum {
+		MERGE_DIRECTORY_RENAMES_NONE = 0,
+		MERGE_DIRECTORY_RENAMES_CONFLICT = 1,
+		MERGE_DIRECTORY_RENAMES_TRUE = 2
+	} detect_directory_renames;
+	int rename_limit;
+	int rename_score;
+	int show_rename_progress;
+
+	/* xdiff-related options (patience, ignore whitespace, ours/theirs) */
+	long xdl_opts;
+	int conflict_style;
+	enum {
+		MERGE_VARIANT_NORMAL = 0,
+		MERGE_VARIANT_OURS,
+		MERGE_VARIANT_THEIRS
+	} recursive_variant;
+
+	/* console output related options */
+	int verbosity;
+	unsigned buffer_output; /* 1: output at end, 2: keep buffered */
+	struct strbuf obuf;     /* output buffer; if buffer_output == 2, caller
+				 * must handle and call strbuf_release */
+
+	/* miscellaneous control options */
+	const char *subtree_shift;
+	unsigned renormalize : 1;
+	unsigned record_conflict_msgs_as_headers : 1;
+	const char *msg_header_prefix;
+
+	/* internal fields used by the implementation */
+	struct merge_options_internal *priv;
+};
+
 /* Mostly internal function also used by merge-ort-wrappers.c */
 struct commit *make_virtual_commit(struct repository *repo,
 				   struct tree *tree,
@@ -119,4 +165,16 @@ void merge_get_conflicted_files(struct merge_result *result,
 void merge_finalize(struct merge_options *opt,
 		    struct merge_result *result);
 
+
+/* for use by porcelain commands */
+void init_ui_merge_options(struct merge_options *opt, struct repository *repo);
+/* for use by plumbing commands */
+void init_basic_merge_options(struct merge_options *opt, struct repository *repo);
+
+void copy_merge_options(struct merge_options *dst, struct merge_options *src);
+void clear_merge_options(struct merge_options *opt);
+
+/* parse the option in s and update the relevant field of opt */
+int parse_merge_opt(struct merge_options *opt, const char *s);
+
 #endif

merge-recursive.h

@@ -1,132 +0,0 @@
-#ifndef MERGE_RECURSIVE_H
-#define MERGE_RECURSIVE_H
-
-#include "strbuf.h"
-
-struct commit;
-struct commit_list;
-struct object_id;
-struct repository;
-struct tree;
-
-struct merge_options_internal;
-struct merge_options {
-	struct repository *repo;
-
-	/* ref names used in console messages and conflict markers */
-	const char *ancestor;
-	const char *branch1;
-	const char *branch2;
-
-	/* rename related options */
-	int detect_renames;
-	enum {
-		MERGE_DIRECTORY_RENAMES_NONE = 0,
-		MERGE_DIRECTORY_RENAMES_CONFLICT = 1,
-		MERGE_DIRECTORY_RENAMES_TRUE = 2
-	} detect_directory_renames;
-	int rename_limit;
-	int rename_score;
-	int show_rename_progress;
-
-	/* xdiff-related options (patience, ignore whitespace, ours/theirs) */
-	long xdl_opts;
-	int conflict_style;
-	enum {
-		MERGE_VARIANT_NORMAL = 0,
-		MERGE_VARIANT_OURS,
-		MERGE_VARIANT_THEIRS
-	} recursive_variant;
-
-	/* console output related options */
-	int verbosity;
-	unsigned buffer_output; /* 1: output at end, 2: keep buffered */
-	struct strbuf obuf;     /* output buffer; if buffer_output == 2, caller
-				 * must handle and call strbuf_release */
-
-	/* miscellaneous control options */
-	const char *subtree_shift;
-	unsigned renormalize : 1;
-	unsigned record_conflict_msgs_as_headers : 1;
-	const char *msg_header_prefix;
-
-	/* internal fields used by the implementation */
-	struct merge_options_internal *priv;
-};
-
-/* for use by porcelain commands */
-void init_ui_merge_options(struct merge_options *opt, struct repository *repo);
-/* for use by plumbing commands */
-void init_basic_merge_options(struct merge_options *opt, struct repository *repo);
-
-void copy_merge_options(struct merge_options *dst, struct merge_options *src);
-void clear_merge_options(struct merge_options *opt);
-
-/* parse the option in s and update the relevant field of opt */
-int parse_merge_opt(struct merge_options *opt, const char *s);
-
-/*
- * RETURN VALUES: All the merge_* functions below return a value as follows:
- *   > 0     Merge was clean
- *   = 0     Merge had conflicts
- *   < 0     Merge hit an unexpected and unrecoverable problem (e.g. disk
- *             full) and aborted merge part-way through.
- */
-
-/*
- * rename-detecting three-way merge, no recursion.
- *
- * Outputs:
- *   - See RETURN VALUES above
- *   - opt->repo->index has the new index
- *   - new index NOT written to disk
- *   - The working tree is updated with results of the merge
- */
-int merge_trees(struct merge_options *opt,
-		struct tree *head,
-		struct tree *merge,
-		struct tree *merge_base);
-
-/*
- * merge_recursive is like merge_trees() but with recursive ancestor
- * consolidation.
- *
- * NOTE: empirically, about a decade ago it was determined that with more
- *       than two merge bases, optimal behavior was found when the
- *       merge_bases were passed in the order of oldest commit to newest
- *       commit.  Also, merge_bases will be consumed (emptied) so make a
- *       copy if you need it.
- *
- * Outputs:
- *   - See RETURN VALUES above
- *   - *result is treated as scratch space for temporary recursive merges
- *   - opt->repo->index has the new index
- *   - new index NOT written to disk
- *   - The working tree is updated with results of the merge
- */
-int merge_recursive(struct merge_options *opt,
-		    struct commit *h1,
-		    struct commit *h2,
-		    const struct commit_list *merge_bases,
-		    struct commit **result);
-
-/*
- * merge_recursive_generic can operate on trees instead of commits, by
- * wrapping the trees into virtual commits, and calling merge_recursive().
- * It also writes out the in-memory index to disk if the merge is successful.
- *
- * Outputs:
- *   - See RETURN VALUES above
- *   - *result is treated as scratch space for temporary recursive merges
- *   - opt->repo->index has the new index
- *   - new index also written to $GIT_INDEX_FILE on disk
- *   - The working tree is updated with results of the merge
- */
-int merge_recursive_generic(struct merge_options *opt,
-			    const struct object_id *head,
-			    const struct object_id *merge,
-			    int num_merge_bases,
-			    const struct object_id *merge_bases,
-			    struct commit **result);
-
-#endif

meson.build

@@ -372,7 +372,6 @@ libgit_sources = [
   'merge-ll.c',
   'merge-ort.c',
   'merge-ort-wrappers.c',
-  'merge-recursive.c',
   'merge.c',
   'midx.c',
   'midx-write.c',

sequencer.c

@@ -781,28 +781,19 @@ static int do_recursive_merge(struct repository *r,
 	for (i = 0; i < opts->xopts.nr; i++)
 		parse_merge_opt(&o, opts->xopts.v[i]);
 
-	if (!opts->strategy || !strcmp(opts->strategy, "ort")) {
+	memset(&result, 0, sizeof(result));
-		memset(&result, 0, sizeof(result));
+	merge_incore_nonrecursive(&o, base_tree, head_tree, next_tree, &result);
-		merge_incore_nonrecursive(&o, base_tree, head_tree, next_tree,
+	show_output = !is_rebase_i(opts) || !result.clean;
-					    &result);
+	/*
-		show_output = !is_rebase_i(opts) || !result.clean;
+	 * TODO: merge_switch_to_result will update index/working tree;
-		/*
+	 * we only really want to do that if !result.clean || this is
-		 * TODO: merge_switch_to_result will update index/working tree;
+	 * the final patch to be picked.  But determining this is the
-		 * we only really want to do that if !result.clean || this is
+	 * final patch would take some work, and "head_tree" would need
-		 * the final patch to be picked.  But determining this is the
+	 * to be replace with the tree the index matched before we
-		 * final patch would take some work, and "head_tree" would need
+	 * started doing any picks.
-		 * to be replace with the tree the index matched before we
+	 */
-		 * started doing any picks.
+	merge_switch_to_result(&o, head_tree, &result, 1, show_output);
-		 */
+	clean = result.clean;
-		merge_switch_to_result(&o, head_tree, &result, 1, show_output);
-		clean = result.clean;
-	} else {
-		ensure_full_index(r->index);
-		clean = merge_trees(&o, head_tree, next_tree, base_tree);
-		if (is_rebase_i(opts) && clean <= 0)
-			fputs(o.obuf.buf, stdout);
-		strbuf_release(&o.obuf);
-	}
 	if (clean < 0) {
 		rollback_lock_file(&index_lock);
 		return clean;
@@ -4328,20 +4319,13 @@ static int do_merge(struct repository *r,
 	o.branch2 = ref_name.buf;
 	o.buffer_output = 2;
 
-	if (!opts->strategy || !strcmp(opts->strategy, "ort")) {
+	/*
-		/*
+	 * TODO: Should use merge_incore_recursive() and
-		 * TODO: Should use merge_incore_recursive() and
+	 * merge_switch_to_result(), skipping the call to
-		 * merge_switch_to_result(), skipping the call to
+	 * merge_switch_to_result() when we don't actually need to
-		 * merge_switch_to_result() when we don't actually need to
+	 * update the index and working copy immediately.
-		 * update the index and working copy immediately.
+	 */
-		 */
+	ret = merge_ort_recursive(&o, head_commit, merge_commit, bases, &i);
-		ret = merge_ort_recursive(&o,
-					  head_commit, merge_commit, bases,
-					  &i);
-	} else {
-		ret = merge_recursive(&o, head_commit, merge_commit, bases,
-				      &i);
-	}
 	if (ret <= 0)
 		fputs(o.obuf.buf, stdout);
 	strbuf_release(&o.obuf);
@@ -4352,7 +4336,7 @@ static int do_merge(struct repository *r,
 		goto leave_merge;
 	}
 	/*
-	 * The return value of merge_recursive() is 1 on clean, and 0 on
+	 * The return value of merge_ort_recursive() is 1 on clean, and 0 on
 	 * unclean merge.
 	 *
 	 * Let's reverse that, so that do_merge() returns 0 upon success and

t/lib-merge.sh

@@ -1,13 +0,0 @@
-# Helper functions used by merge tests.
-
-test_expect_merge_algorithm () {
-	status_for_recursive=$1 status_for_ort=$2
-	shift 2
-
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
-	then
-		test_expect_${status_for_ort} "$@"
-	else
-		test_expect_${status_for_recursive} "$@"
-	fi
-}

t/t1092-sparse-checkout-compatibility.sh

@@ -1486,7 +1486,6 @@ test_expect_success 'sparse-index is not expanded' '
 	ensure_not_expanded checkout -f update-deep &&
 	test_config -C sparse-index pull.twohead ort &&
 	(
-		sane_unset GIT_TEST_MERGE_ALGORITHM &&
 		for OPERATION in "merge -m merge" cherry-pick rebase
 		do
 			ensure_not_expanded merge -m merge update-folder1 &&
@@ -1506,7 +1505,6 @@ test_expect_success 'sparse-index is not expanded: merge conflict in cone' '
 	done &&
 
 	(
-		sane_unset GIT_TEST_MERGE_ALGORITHM &&
 		git -C sparse-index config pull.twohead ort &&
 		ensure_not_expanded ! merge -m merged expand-right
 	)

t/t2501-cwd-empty.sh

@@ -117,8 +117,6 @@ test_expect_success 'merge fails if cwd needs to be removed; recursive friendly'
 	grep "Refusing to remove the current working directory" error
 '
 
-GIT_TEST_MERGE_ALGORITHM=ort
-
 test_expect_success 'merge fails if cwd needs to be removed' '
 	test_required_dir_removal git merge fd_conflict
 '

t/t3512-cherry-pick-submodule.sh

@@ -8,11 +8,6 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 . ./test-lib.sh
 . "$TEST_DIRECTORY"/lib-submodule-update.sh
 
-if test "$GIT_TEST_MERGE_ALGORITHM" != ort
-then
-	KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1
-	KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1
-fi
 test_submodule_switch "cherry-pick"
 
 test_expect_success 'unrelated submodule/file conflict is ignored' '

t/t3513-revert-submodule.sh

@@ -30,10 +30,6 @@ git_revert () {
 	git revert HEAD
 }
 
-if test "$GIT_TEST_MERGE_ALGORITHM" != ort
-then
-	KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1
-fi
 test_submodule_switch_func "git_revert"
 
 test_done

t/t4069-remerge-diff.sh

@@ -4,13 +4,6 @@ test_description='remerge-diff handling'
 
 . ./test-lib.sh
 
-# This test is ort-specific
-if test "${GIT_TEST_MERGE_ALGORITHM}" != ort
-then
-	skip_all="GIT_TEST_MERGE_ALGORITHM != ort"
-	test_done
-fi
-
 test_expect_success 'setup basic merges' '
 	test_write_lines 1 2 3 4 5 6 7 8 9 >numbers &&
 	git add numbers &&

t/t4301-merge-tree-write-tree.sh

@@ -4,13 +4,6 @@ test_description='git merge-tree --write-tree'
 
 . ./test-lib.sh
 
-# This test is ort-specific
-if test "$GIT_TEST_MERGE_ALGORITHM" != "ort"
-then
-	skip_all="GIT_TEST_MERGE_ALGORITHM != ort"
-	test_done
-fi
-
 test_expect_success setup '
 	test_write_lines 1 2 3 4 5 >numbers &&
 	echo hello >greeting &&

t/t5572-pull-submodule.sh

@@ -45,11 +45,6 @@ git_pull_noff () {
 	$2 git pull --no-ff
 }
 
-if test "$GIT_TEST_MERGE_ALGORITHM" != ort
-then
-	KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1
-	KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1
-fi
 test_submodule_switch_func "git_pull_noff"
 
 test_expect_success 'setup' '

t/t6400-merge-df.sh

@@ -84,12 +84,7 @@ test_expect_success 'modify/delete + directory/file conflict' '
 
 	test_stdout_line_count = 5 git ls-files -s &&
 	test_stdout_line_count = 4 git ls-files -u &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_stdout_line_count = 0 git ls-files -o &&
-	then
-		test_stdout_line_count = 0 git ls-files -o
-	else
-		test_stdout_line_count = 1 git ls-files -o
-	fi &&
 
 	test_path_is_file letters/file &&
 	test_path_is_file letters.txt &&
@@ -105,12 +100,7 @@ test_expect_success 'modify/delete + directory/file conflict; other way' '
 
 	test_stdout_line_count = 5 git ls-files -s &&
 	test_stdout_line_count = 4 git ls-files -u &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_stdout_line_count = 0 git ls-files -o &&
-	then
-		test_stdout_line_count = 0 git ls-files -o
-	else
-		test_stdout_line_count = 1 git ls-files -o
-	fi &&
 
 	test_path_is_file letters/file &&
 	test_path_is_file letters.txt &&

t/t6402-merge-rename.sh

@@ -313,12 +313,7 @@ test_expect_success 'Rename+D/F conflict; renamed file merges but dir in way' '
 
 	test_grep "CONFLICT (modify/delete): dir/file-in-the-way" output &&
 	test_grep "Auto-merging dir" output &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_grep "moving it to dir~HEAD instead" output &&
-	then
-		test_grep "moving it to dir~HEAD instead" output
-	else
-		test_grep "Adding as dir~HEAD instead" output
-	fi &&
 
 	test_stdout_line_count = 3 git ls-files -u &&
 	test_stdout_line_count = 2 git ls-files -u dir/file-in-the-way &&
@@ -340,12 +335,7 @@ test_expect_success 'Same as previous, but merged other way' '
 	! grep "error: refusing to lose untracked file at" errors &&
 	test_grep "CONFLICT (modify/delete): dir/file-in-the-way" output &&
 	test_grep "Auto-merging dir" output &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_grep "moving it to dir~renamed-file-has-no-conflicts instead" output &&
-	then
-		test_grep "moving it to dir~renamed-file-has-no-conflicts instead" output
-	else
-		test_grep "Adding as dir~renamed-file-has-no-conflicts instead" output
-	fi &&
 
 	test_stdout_line_count = 3 git ls-files -u &&
 	test_stdout_line_count = 2 git ls-files -u dir/file-in-the-way &&
@@ -400,14 +390,7 @@ test_expect_success 'Rename+D/F conflict; renamed file cannot merge and dir in t
 	test_must_fail git merge --strategy=recursive dir-in-way &&
 
 	test_stdout_line_count = 5 git ls-files -u &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_stdout_line_count = 3 git ls-files -u dir~HEAD &&
-	then
-		test_stdout_line_count = 3 git ls-files -u dir~HEAD
-	else
-		git ls-files -u dir >out &&
-		test 3 -eq $(grep -v file-in-the-way out | wc -l) &&
-		rm -f out
-	fi &&
 	test_stdout_line_count = 2 git ls-files -u dir/file-in-the-way &&
 
 	test_must_fail git diff --quiet &&
@@ -425,14 +408,7 @@ test_expect_success 'Same as previous, but merged other way' '
 	test_must_fail git merge --strategy=recursive renamed-file-has-conflicts &&
 
 	test_stdout_line_count = 5 git ls-files -u &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_stdout_line_count = 3 git ls-files -u dir~renamed-file-has-conflicts &&
-	then
-		test_stdout_line_count = 3 git ls-files -u dir~renamed-file-has-conflicts
-	else
-		git ls-files -u dir >out &&
-		test 3 -eq $(grep -v file-in-the-way out | wc -l) &&
-		rm -f out
-	fi &&
 	test_stdout_line_count = 2 git ls-files -u dir/file-in-the-way &&
 
 	test_must_fail git diff --quiet &&
@@ -488,12 +464,7 @@ test_expect_success 'both rename source and destination involved in D/F conflict
 	git checkout -q rename-dest^0 &&
 	test_must_fail git merge --strategy=recursive source-conflict &&
 
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_stdout_line_count = 2 git ls-files -u &&
-	then
-		test_stdout_line_count = 2 git ls-files -u
-	else
-		test_stdout_line_count = 1 git ls-files -u
-	fi &&
 
 	test_must_fail git diff --quiet &&
 
@@ -527,63 +498,33 @@ test_expect_success 'setup pair rename to parent of other (D/F conflicts)' '
 	git commit -m "Rename one/file -> two"
 '
 
-if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+test_expect_success 'pair rename to parent of other (D/F conflicts) w/ untracked dir' '
-then
+	git checkout -q rename-one^0 &&
-	test_expect_success 'pair rename to parent of other (D/F conflicts) w/ untracked dir' '
+	mkdir one &&
-		git checkout -q rename-one^0 &&
+	test_must_fail git merge --strategy=recursive rename-two &&
-		mkdir one &&
-		test_must_fail git merge --strategy=recursive rename-two &&
 
-		test_stdout_line_count = 4 git ls-files -u &&
+	test_stdout_line_count = 4 git ls-files -u &&
-		test_stdout_line_count = 2 git ls-files -u one &&
+	test_stdout_line_count = 2 git ls-files -u one &&
-		test_stdout_line_count = 2 git ls-files -u two &&
+	test_stdout_line_count = 2 git ls-files -u two &&
 
-		test_must_fail git diff --quiet &&
+	test_must_fail git diff --quiet &&
 
-		test 3 -eq $(find . | grep -v .git | wc -l) &&
+	test 3 -eq $(find . | grep -v .git | wc -l) &&
 
-		test_path_is_file one &&
+	test_path_is_file one &&
-		test_path_is_file two &&
+	test_path_is_file two &&
-		test "other" = $(cat one) &&
+	test "other" = $(cat one) &&
-		test "stuff" = $(cat two)
+	test "stuff" = $(cat two)
-	'
+'
-else
-	test_expect_success 'pair rename to parent of other (D/F conflicts) w/ untracked dir' '
-		git checkout -q rename-one^0 &&
-		mkdir one &&
-		test_must_fail git merge --strategy=recursive rename-two &&
-
-		test_stdout_line_count = 2 git ls-files -u &&
-		test_stdout_line_count = 1 git ls-files -u one &&
-		test_stdout_line_count = 1 git ls-files -u two &&
-
-		test_must_fail git diff --quiet &&
-
-		test 4 -eq $(find . | grep -v .git | wc -l) &&
-
-		test_path_is_dir one &&
-		test_path_is_file one~rename-two &&
-		test_path_is_file two &&
-		test "other" = $(cat one~rename-two) &&
-		test "stuff" = $(cat two)
-	'
-fi
 
 test_expect_success 'pair rename to parent of other (D/F conflicts) w/ clean start' '
 	git reset --hard &&
 	git clean -fdqx &&
 	test_must_fail git merge --strategy=recursive rename-two &&
 
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_stdout_line_count = 4 git ls-files -u &&
-	then
+	test_stdout_line_count = 2 git ls-files -u one &&
-		test_stdout_line_count = 4 git ls-files -u &&
+	test_stdout_line_count = 2 git ls-files -u two &&
-		test_stdout_line_count = 2 git ls-files -u one &&
-		test_stdout_line_count = 2 git ls-files -u two
-	else
-		test_stdout_line_count = 2 git ls-files -u &&
-		test_stdout_line_count = 1 git ls-files -u one &&
-		test_stdout_line_count = 1 git ls-files -u two
-	fi &&
 
 	test_must_fail git diff --quiet &&
 
@@ -623,22 +564,12 @@ test_expect_success 'check handling of differently renamed file with D/F conflic
 	git checkout -q first-rename^0 &&
 	test_must_fail git merge --strategy=recursive second-rename &&
 
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_stdout_line_count = 5 git ls-files -s &&
-	then
+	test_stdout_line_count = 3 git ls-files -u &&
-		test_stdout_line_count = 5 git ls-files -s &&
+	test_stdout_line_count = 1 git ls-files -u one~HEAD &&
-		test_stdout_line_count = 3 git ls-files -u &&
+	test_stdout_line_count = 1 git ls-files -u two~second-rename &&
-		test_stdout_line_count = 1 git ls-files -u one~HEAD &&
+	test_stdout_line_count = 1 git ls-files -u original &&
-		test_stdout_line_count = 1 git ls-files -u two~second-rename &&
+	test_stdout_line_count = 0 git ls-files -o &&
-		test_stdout_line_count = 1 git ls-files -u original &&
-		test_stdout_line_count = 0 git ls-files -o
-	else
-		test_stdout_line_count = 5 git ls-files -s &&
-		test_stdout_line_count = 3 git ls-files -u &&
-		test_stdout_line_count = 1 git ls-files -u one &&
-		test_stdout_line_count = 1 git ls-files -u two &&
-		test_stdout_line_count = 1 git ls-files -u original &&
-		test_stdout_line_count = 2 git ls-files -o
-	fi &&
 
 	test_path_is_file one/file &&
 	test_path_is_file two/file &&

t/t6404-recursive-merge.sh

@@ -108,12 +108,7 @@ test_expect_success 'refuse to merge binary files' '
 	printf "\0\0" >binary-file &&
 	git add binary-file &&
 	git commit -m binary2 &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_must_fail git merge F >merge_output &&
-	then
-		test_must_fail git merge F >merge_output
-	else
-		test_must_fail git merge F 2>merge_output
-	fi &&
 	grep "Cannot merge binary files: binary-file (HEAD vs. F)" merge_output
 '
 
@@ -129,22 +124,12 @@ test_expect_success 'mark rename/delete as unmerged' '
 	test_tick &&
 	git commit -m rename &&
 	test_must_fail git merge delete &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test 2 = $(git ls-files --unmerged | wc -l) &&
-	then
-		test 2 = $(git ls-files --unmerged | wc -l)
-	else
-		test 1 = $(git ls-files --unmerged | wc -l)
-	fi &&
 	git rev-parse --verify :2:a2 &&
 	test_must_fail git rev-parse --verify :3:a2 &&
 	git checkout -f delete &&
 	test_must_fail git merge rename &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test 2 = $(git ls-files --unmerged | wc -l) &&
-	then
-		test 2 = $(git ls-files --unmerged | wc -l)
-	else
-		test 1 = $(git ls-files --unmerged | wc -l)
-	fi &&
 	test_must_fail git rev-parse --verify :2:a2 &&
 	git rev-parse --verify :3:a2
 '

t/t6406-merge-attr.sh

@@ -259,12 +259,7 @@ test_expect_success 'binary files with union attribute' '
 	printf "two\0" >bin.txt &&
 	git commit -am two &&
 
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_must_fail git merge bin-main >output &&
-	then
-		test_must_fail git merge bin-main >output
-	else
-		test_must_fail git merge bin-main 2>output
-	fi &&
 	grep -i "warning.*cannot merge.*HEAD vs. bin-main" output
 '
 

t/t6416-recursive-corner-cases.sh

@@ -6,7 +6,6 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-merge.sh
 
 #
 #  L1  L2
@@ -529,15 +528,8 @@ test_expect_success 'setup differently handled merges of directory/file conflict
 
 		git checkout B^0 &&
 		test_must_fail git merge C^0 &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git rm -rf a/ &&
-		then
+		git rm a~HEAD &&
-			git rm -rf a/ &&
-			git rm a~HEAD
-		else
-			git clean -fd &&
-			git rm -rf a/ &&
-			git rm a
-		fi &&
 		git cat-file -p B:a >a2 &&
 		git add a2 &&
 		git commit -m D2 &&
@@ -556,12 +548,7 @@ test_expect_success 'setup differently handled merges of directory/file conflict
 
 		git checkout C^0 &&
 		test_must_fail git merge B^0 &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git rm a~B^0 &&
-		then
-			git rm a~B^0
-		else
-			git clean -fd
-		fi &&
 		git rm -rf a/ &&
 		test_write_lines 1 2 3 4 5 6 7 8 >a &&
 		git add a &&
@@ -570,15 +557,8 @@ test_expect_success 'setup differently handled merges of directory/file conflict
 
 		git checkout C^0 &&
 		test_must_fail git merge B^0 &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git rm -rf a/ &&
-		then
+		git rm a~B^0 &&
-			git rm -rf a/ &&
-			git rm a~B^0
-		else
-			git clean -fd &&
-			git rm -rf a/ &&
-			git rm a
-		fi &&
 		test_write_lines 1 2 3 4 5 6 7 8 >a2 &&
 		git add a2 &&
 		git commit -m E4 &&
@@ -596,34 +576,16 @@ test_expect_success 'merge of D1 & E1 fails but has appropriate contents' '
 
 		test_must_fail git merge -s recursive E1^0 &&
 
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git ls-files -s >out &&
-		then
+		test_line_count = 3 out &&
-			git ls-files -s >out &&
+		git ls-files -u >out &&
-			test_line_count = 3 out &&
+		test_line_count = 2 out &&
-			git ls-files -u >out &&
+		git ls-files -o >out &&
-			test_line_count = 2 out &&
+		test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
 
-			git rev-parse >expect    \
+		git rev-parse >expect    A:ignore-me  B:a D1:a &&
-				A:ignore-me  B:a  D1:a &&
+		git rev-parse >actual   :0:ignore-me :1:a :2:a &&
-			git rev-parse   >actual   \
+		test_cmp expect actual
-				:0:ignore-me :1:a :2:a &&
-			test_cmp expect actual
-		else
-			git ls-files -s >out &&
-			test_line_count = 2 out &&
-			git ls-files -u >out &&
-			test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
-
-			git rev-parse >expect    \
-				A:ignore-me  B:a &&
-			git rev-parse   >actual   \
-				:0:ignore-me :2:a &&
-			test_cmp expect actual
-		fi
 	)
 '
 
@@ -637,34 +599,18 @@ test_expect_success 'merge of E1 & D1 fails but has appropriate contents' '
 
 		test_must_fail git merge -s recursive D1^0 &&
 
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git ls-files -s >out &&
-		then
+		test_line_count = 3 out &&
-			git ls-files -s >out &&
+		git ls-files -u >out &&
-			test_line_count = 3 out &&
+		test_line_count = 2 out &&
-			git ls-files -u >out &&
+		git ls-files -o >out &&
-			test_line_count = 2 out &&
+		test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
 
-			git rev-parse >expect    \
+		git rev-parse >expect    \
-				A:ignore-me  B:a  D1:a &&
+			A:ignore-me  B:a  D1:a &&
-			git rev-parse   >actual   \
+		git rev-parse   >actual   \
-				:0:ignore-me :1:a :3:a &&
+			:0:ignore-me :1:a :3:a &&
-			test_cmp expect actual
+		test_cmp expect actual
-		else
-			git ls-files -s >out &&
-			test_line_count = 2 out &&
-			git ls-files -u >out &&
-			test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
-
-			git rev-parse >expect    \
-				A:ignore-me  B:a &&
-			git rev-parse   >actual   \
-				:0:ignore-me :3:a &&
-			test_cmp expect actual
-		fi
 	)
 '
 
@@ -678,32 +624,17 @@ test_expect_success 'merge of D1 & E2 fails but has appropriate contents' '
 
 		test_must_fail git merge -s recursive E2^0 &&
 
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git ls-files -s >out &&
-		then
+		test_line_count = 5 out &&
-			git ls-files -s >out &&
+		git ls-files -u >out &&
-			test_line_count = 5 out &&
+		test_line_count = 4 out &&
-			git ls-files -u >out &&
+		git ls-files -o >out &&
-			test_line_count = 4 out &&
+		test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
 
-			git rev-parse >expect    \
+		git rev-parse >expect    \
-				B:a       D1:a      E2:a/file  C:a/file   A:ignore-me &&
+			B:a       D1:a      E2:a/file  C:a/file   A:ignore-me &&
-			git rev-parse   >actual   \
+		git rev-parse   >actual   \
-				:1:a~HEAD :2:a~HEAD :3:a/file  :1:a/file  :0:ignore-me
+			:1:a~HEAD :2:a~HEAD :3:a/file  :1:a/file  :0:ignore-me &&
-		else
-			git ls-files -s >out &&
-			test_line_count = 4 out &&
-			git ls-files -u >out &&
-			test_line_count = 3 out &&
-			git ls-files -o >out &&
-			test_line_count = 2 out &&
-
-			git rev-parse >expect    \
-				B:a    E2:a/file  C:a/file   A:ignore-me &&
-			git rev-parse   >actual   \
-				:2:a   :3:a/file  :1:a/file  :0:ignore-me
-		fi &&
 		test_cmp expect actual &&
 
 		test_path_is_file a~HEAD
@@ -720,32 +651,17 @@ test_expect_success 'merge of E2 & D1 fails but has appropriate contents' '
 
 		test_must_fail git merge -s recursive D1^0 &&
 
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git ls-files -s >out &&
-		then
+		test_line_count = 5 out &&
-			git ls-files -s >out &&
+		git ls-files -u >out &&
-			test_line_count = 5 out &&
+		test_line_count = 4 out &&
-			git ls-files -u >out &&
+		git ls-files -o >out &&
-			test_line_count = 4 out &&
+		test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
 
-			git rev-parse >expect    \
+		git rev-parse >expect    \
-				B:a       D1:a      E2:a/file  C:a/file   A:ignore-me &&
+			B:a       D1:a      E2:a/file  C:a/file   A:ignore-me &&
-			git rev-parse   >actual   \
+		git rev-parse   >actual   \
-				:1:a~D1^0 :3:a~D1^0 :2:a/file  :1:a/file  :0:ignore-me
+			:1:a~D1^0 :3:a~D1^0 :2:a/file  :1:a/file  :0:ignore-me &&
-		else
-			git ls-files -s >out &&
-			test_line_count = 4 out &&
-			git ls-files -u >out &&
-			test_line_count = 3 out &&
-			git ls-files -o >out &&
-			test_line_count = 2 out &&
-
-			git rev-parse >expect    \
-				B:a   E2:a/file  C:a/file   A:ignore-me &&
-			git rev-parse   >actual   \
-				:3:a  :2:a/file  :1:a/file  :0:ignore-me
-		fi &&
 		test_cmp expect actual &&
 
 		test_path_is_file a~D1^0
@@ -777,7 +693,7 @@ test_expect_success 'merge of D1 & E3 succeeds' '
 	)
 '
 
-test_expect_merge_algorithm failure success 'merge of D1 & E4 puts merge of a and a2 in both a and a2' '
+test_expect_success 'merge of D1 & E4 puts merge of a and a2 in both a and a2' '
 	test_when_finished "git -C directory-file reset --hard" &&
 	test_when_finished "git -C directory-file clean -fdqx" &&
 	(
@@ -1140,7 +1056,7 @@ test_expect_success 'setup symlink modify/modify' '
 	)
 '
 
-test_expect_merge_algorithm failure success 'check symlink modify/modify' '
+test_expect_success 'check symlink modify/modify' '
 	(
 		cd symlink-modify-modify &&
 
@@ -1206,7 +1122,7 @@ test_expect_success 'setup symlink add/add' '
 	)
 '
 
-test_expect_merge_algorithm failure success 'check symlink add/add' '
+test_expect_success 'check symlink add/add' '
 	(
 		cd symlink-add-add &&
 
@@ -1294,7 +1210,7 @@ test_expect_success 'setup submodule modify/modify' '
 	)
 '
 
-test_expect_merge_algorithm failure success 'check submodule modify/modify' '
+test_expect_success 'check submodule modify/modify' '
 	(
 		cd submodule-modify-modify &&
 
@@ -1382,7 +1298,7 @@ test_expect_success 'setup submodule add/add' '
 	)
 '
 
-test_expect_merge_algorithm failure success 'check submodule add/add' '
+test_expect_success 'check submodule add/add' '
 	(
 		cd submodule-add-add &&
 
@@ -1457,7 +1373,7 @@ test_expect_success 'setup conflicting entry types (submodule vs symlink)' '
 	)
 '
 
-test_expect_merge_algorithm failure success 'check conflicting entry types (submodule vs symlink)' '
+test_expect_success 'check conflicting entry types (submodule vs symlink)' '
 	(
 		cd submodule-symlink-add-add &&
 

t/t6421-merge-partial-clone.sh

@@ -27,7 +27,6 @@ test_description="limiting blob downloads when merging with partial clones"
 #                     files that might be renamed into each other's paths.)
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-merge.sh
 
 test_setup_repo () {
 	test -d server && return
@@ -207,7 +206,7 @@ test_setup_repo () {
 #
 #   Summary: 2 fetches (1 for 2 objects, 1 for 1 object)
 #
-test_expect_merge_algorithm failure success 'Objects downloaded for single relevant rename' '
+test_expect_success 'Objects downloaded for single relevant rename' '
 	test_setup_repo &&
 	git clone --sparse --filter=blob:none "file://$(pwd)/server" objects-single &&
 	(
@@ -297,7 +296,7 @@ test_expect_merge_algorithm failure success 'Objects downloaded for single relev
 #      this are not all that common.)
 #   Summary: 1 fetches for 6 objects
 #
-test_expect_merge_algorithm failure success 'Objects downloaded when a directory rename triggered' '
+test_expect_success 'Objects downloaded when a directory rename triggered' '
 	test_setup_repo &&
 	git clone --sparse --filter=blob:none "file://$(pwd)/server" objects-dir &&
 	(
@@ -399,7 +398,7 @@ test_expect_merge_algorithm failure success 'Objects downloaded when a directory
 #
 #   Summary: 4 fetches (1 for 6 objects, 1 for 8, 1 for 3, 1 for 2)
 #
-test_expect_merge_algorithm failure success 'Objects downloaded with lots of renames and modifications' '
+test_expect_success 'Objects downloaded with lots of renames and modifications' '
 	test_setup_repo &&
 	git clone --sparse --filter=blob:none "file://$(pwd)/server" objects-many &&
 	(

t/t6422-merge-rename-corner-cases.sh

@@ -7,7 +7,6 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-merge.sh
 
 test_setup_rename_delete_untracked () {
 	git init rename-delete-untracked &&
@@ -316,12 +315,7 @@ test_expect_success 'rename/directory conflict + clean content merge' '
 		git ls-files -u >out &&
 		test_line_count = 1 out &&
 		git ls-files -o >out &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_line_count = 1 out &&
-		then
-			test_line_count = 1 out
-		else
-			test_line_count = 2 out
-		fi &&
 
 		echo 0 >expect &&
 		git cat-file -p base:file >>expect &&
@@ -350,12 +344,7 @@ test_expect_success 'rename/directory conflict + content merge conflict' '
 		git ls-files -u >out &&
 		test_line_count = 3 out &&
 		git ls-files -o >out &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_line_count = 1 out &&
-		then
-			test_line_count = 1 out
-		else
-			test_line_count = 2 out
-		fi &&
 
 		git cat-file -p left-conflict:newfile >left &&
 		git cat-file -p base:file    >base &&
@@ -369,14 +358,8 @@ test_expect_success 'rename/directory conflict + content merge conflict' '
 
 		git rev-parse >expect   \
 			base:file       left-conflict:newfile right:file &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git rev-parse >actual \
-		then
+			:1:newfile~HEAD :2:newfile~HEAD :3:newfile~HEAD &&
-			git rev-parse >actual \
-				:1:newfile~HEAD :2:newfile~HEAD :3:newfile~HEAD
-		else
-			git rev-parse >actual \
-				:1:newfile      :2:newfile      :3:newfile
-		fi &&
 		test_cmp expect actual &&
 
 		test_path_is_file newfile/realfile &&
@@ -896,7 +879,7 @@ test_setup_rad () {
 	)
 }
 
-test_expect_merge_algorithm failure success 'rad-check: rename/add/delete conflict' '
+test_expect_success 'rad-check: rename/add/delete conflict' '
 	test_setup_rad &&
 	(
 		cd rad &&
@@ -969,7 +952,7 @@ test_setup_rrdd () {
 	)
 }
 
-test_expect_merge_algorithm failure success 'rrdd-check: rename/rename(2to1)/delete/delete conflict' '
+test_expect_success 'rrdd-check: rename/rename(2to1)/delete/delete conflict' '
 	test_setup_rrdd &&
 	(
 		cd rrdd &&
@@ -1058,7 +1041,7 @@ test_setup_mod6 () {
 	)
 }
 
-test_expect_merge_algorithm failure success 'mod6-check: chains of rename/rename(1to2) and rename/rename(2to1)' '
+test_expect_success 'mod6-check: chains of rename/rename(1to2) and rename/rename(2to1)' '
 	test_setup_mod6 &&
 	(
 		cd mod6 &&

t/t6423-merge-rename-directories.sh

@@ -26,8 +26,6 @@ test_description="recursive merge with directory renames"
 #                     files that might be renamed into each other's paths.)
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-merge.sh
-
 
 ###########################################################################
 # SECTION 1: Basic cases we should be able to handle
@@ -302,20 +300,11 @@ test_expect_success '1d: Directory renames cause a rename/rename(2to1) conflict'
 		git cat-file -p :2:x/wham >expect &&
 		git cat-file -p :3:x/wham >other &&
 		>empty &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_must_fail git merge-file \
-		then
+			-L "HEAD:y/wham" \
-			test_must_fail git merge-file \
+			-L "" \
-				-L "HEAD:y/wham" \
+			-L "B^0:z/wham" \
-				-L "" \
+			expect empty other &&
-				-L "B^0:z/wham" \
-				expect empty other
-		else
-			test_must_fail git merge-file \
-				-L "HEAD" \
-				-L "" \
-				-L "B^0" \
-				expect empty other
-		fi &&
 		test_cmp expect x/wham
 	)
 '
@@ -1186,18 +1175,10 @@ test_expect_success '5d: Directory/file/file conflict due to directory rename' '
 		git ls-files -u >out &&
 		test_line_count = 1 out &&
 		git ls-files -o >out &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_line_count = 1 out &&
-		then
-			test_line_count = 1 out &&
 
-			git rev-parse >actual \
+		git rev-parse >actual \
-			    :0:y/b :0:y/c :0:z/d :0:y/f :2:y/d~HEAD :0:y/d/e
+		    :0:y/b :0:y/c :0:z/d :0:y/f :2:y/d~HEAD :0:y/d/e &&
-		else
-			test_line_count = 2 out &&
-
-			git rev-parse >actual \
-			    :0:y/b :0:y/c :0:z/d :0:y/f :2:y/d      :0:y/d/e
-		fi &&
 		git rev-parse >expect \
 			 O:z/b  O:z/c  B:z/d  B:z/f  A:y/d  B:y/d/e &&
 		test_cmp expect actual &&
@@ -1280,32 +1261,17 @@ test_expect_success '6a: Tricky rename/delete' '
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out &&
 		test_grep "CONFLICT (rename/delete).*z/c.*y/c" out &&
 
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git ls-files -s >out &&
-		then
+		test_line_count = 3 out &&
-			git ls-files -s >out &&
+		git ls-files -u >out &&
-			test_line_count = 3 out &&
+		test_line_count = 2 out &&
-			git ls-files -u >out &&
+		git ls-files -o >out &&
-			test_line_count = 2 out &&
+		test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
 
-			git rev-parse >actual \
+		git rev-parse >actual \
-				:0:y/b :1:y/c :3:y/c &&
+			:0:y/b :1:y/c :3:y/c &&
-			git rev-parse >expect \
+		git rev-parse >expect \
-				 O:z/b  O:z/c  O:z/c
+			 O:z/b  O:z/c  O:z/c &&
-		else
-			git ls-files -s >out &&
-			test_line_count = 2 out &&
-			git ls-files -u >out &&
-			test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
-
-			git rev-parse >actual \
-				:0:y/b :3:y/c &&
-			git rev-parse >expect \
-				 O:z/b  O:z/c
-		fi &&
 		test_cmp expect actual
 	)
 '
@@ -1372,7 +1338,7 @@ test_setup_6b1 () {
 	)
 }
 
-test_expect_merge_algorithm failure success '6b1: Same renames done on both sides, plus another rename' '
+test_expect_success '6b1: Same renames done on both sides, plus another rename' '
 	test_setup_6b1 &&
 	(
 		cd 6b1 &&
@@ -1445,7 +1411,7 @@ test_setup_6b2 () {
 	)
 }
 
-test_expect_merge_algorithm failure success '6b2: Same rename done on both sides' '
+test_expect_success '6b2: Same rename done on both sides' '
 	test_setup_6b2 &&
 	(
 		cd 6b2 &&
@@ -1832,20 +1798,11 @@ test_expect_success '7b: rename/rename(2to1), but only due to transitive rename'
 		git cat-file -p :2:y/d >expect &&
 		git cat-file -p :3:y/d >other &&
 		>empty &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_must_fail git merge-file \
-		then
+			-L "HEAD:y/d" \
-			test_must_fail git merge-file \
+			-L "" \
-				-L "HEAD:y/d" \
+			-L "B^0:z/d" \
-				-L "" \
+			expect empty other &&
-				-L "B^0:z/d" \
-				expect empty other
-		else
-			test_must_fail git merge-file \
-				-L "HEAD" \
-				-L "" \
-				-L "B^0" \
-				expect empty other
-		fi &&
 		test_cmp expect y/d
 	)
 '
@@ -1967,32 +1924,17 @@ test_expect_success '7d: transitive rename involved in rename/delete; how is it
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out &&
 		test_grep "CONFLICT (rename/delete).*x/d.*y/d" out &&
 
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git ls-files -s >out &&
-		then
+		test_line_count = 4 out &&
-			git ls-files -s >out &&
+		git ls-files -u >out &&
-			test_line_count = 4 out &&
+		test_line_count = 2 out &&
-			git ls-files -u >out &&
+		git ls-files -o >out &&
-			test_line_count = 2 out &&
+		test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
 
-			git rev-parse >actual \
+		git rev-parse >actual \
-				:0:y/b :0:y/c :1:y/d :3:y/d &&
+			:0:y/b :0:y/c :1:y/d :3:y/d &&
-			git rev-parse >expect \
+		git rev-parse >expect \
-				 O:z/b  O:z/c  O:x/d  O:x/d
+			 O:z/b  O:z/c  O:x/d  O:x/d &&
-		else
-			git ls-files -s >out &&
-			test_line_count = 3 out &&
-			git ls-files -u >out &&
-			test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
-
-			git rev-parse >actual \
-				:0:y/b :0:y/c :3:y/d &&
-			git rev-parse >expect \
-				 O:z/b  O:z/c  O:x/d
-		fi &&
 		test_cmp expect actual
 	)
 '
@@ -2073,32 +2015,17 @@ test_expect_success '7e: transitive rename in rename/delete AND dirs in the way'
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out &&
 		test_grep "CONFLICT (rename/delete).*x/d.*y/d" out &&
 
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		git ls-files -s >out &&
-		then
+		test_line_count = 6 out &&
-			git ls-files -s >out &&
+		git ls-files -u >out &&
-			test_line_count = 6 out &&
+		test_line_count = 2 out &&
-			git ls-files -u >out &&
+		git ls-files -o >out &&
-			test_line_count = 2 out &&
+		test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 1 out &&
 
-			git rev-parse >actual \
+		git rev-parse >actual \
-				:0:x/d/f :0:y/d/g :0:y/b :0:y/c :1:y/d~B^0 :3:y/d~B^0 &&
+			:0:x/d/f :0:y/d/g :0:y/b :0:y/c :1:y/d~B^0 :3:y/d~B^0 &&
-			git rev-parse >expect \
+		git rev-parse >expect \
-				 A:x/d/f  A:y/d/g  O:z/b  O:z/c  O:x/d      O:x/d
+			 A:x/d/f  A:y/d/g  O:z/b  O:z/c  O:x/d      O:x/d &&
-		else
-			git ls-files -s >out &&
-			test_line_count = 5 out &&
-			git ls-files -u >out &&
-			test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 2 out &&
-
-			git rev-parse >actual \
-				:0:x/d/f :0:y/d/g :0:y/b :0:y/c :3:y/d &&
-			git rev-parse >expect \
-				 A:x/d/f  A:y/d/g  O:z/b  O:z/c  O:x/d
-		fi &&
 		test_cmp expect actual &&
 
 		git hash-object y/d~B^0 >actual &&
@@ -3284,34 +3211,15 @@ test_expect_success '10b: Overwrite untracked with dir rename + delete' '
 		echo contents >y/e &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: The following untracked working tree files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: The following untracked working tree files would be overwritten by merge" err &&
 
-			git ls-files -s >out &&
+		git ls-files -s >out &&
-			test_line_count = 1 out &&
+		test_line_count = 1 out &&
-			git ls-files -u >out &&
+		git ls-files -u >out &&
-			test_line_count = 0 out &&
+		test_line_count = 0 out &&
-			git ls-files -o >out &&
+		git ls-files -o >out &&
-			test_line_count = 5 out
+		test_line_count = 5 out &&
-		else
-			test_grep "CONFLICT (rename/delete).*Version B\^0 of y/d left in tree at y/d~B\^0" out &&
-			test_grep "Error: Refusing to lose untracked file at y/e; writing to y/e~B\^0 instead" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 3 out &&
-			git ls-files -u >out &&
-			test_line_count = 2 out &&
-			git ls-files -o >out &&
-			test_line_count = 5 out &&
-
-			git rev-parse >actual \
-				:0:y/b :3:y/d :3:y/e &&
-			git rev-parse >expect \
-				O:z/b  O:z/c  B:z/e &&
-			test_cmp expect actual
-		fi &&
 
 		echo very >expect &&
 		test_cmp expect y/c &&
@@ -3374,38 +3282,15 @@ test_expect_success '10c1: Overwrite untracked with dir rename/rename(1to2)' '
 		echo important >y/c &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: The following untracked working tree files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: The following untracked working tree files would be overwritten by merge" err &&
 
-			git ls-files -s >out &&
+		git ls-files -s >out &&
-			test_line_count = 4 out &&
+		test_line_count = 4 out &&
-			git ls-files -u >out &&
+		git ls-files -u >out &&
-			test_line_count = 0 out &&
+		test_line_count = 0 out &&
-			git ls-files -o >out &&
+		git ls-files -o >out &&
-			test_line_count = 3 out
+		test_line_count = 3 out &&
-		else
-			test_grep "CONFLICT (rename/rename)" out &&
-			test_grep "Refusing to lose untracked file at y/c; adding as y/c~B\^0 instead" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 6 out &&
-			git ls-files -u >out &&
-			test_line_count = 3 out &&
-			git ls-files -o >out &&
-			test_line_count = 3 out &&
-
-			git rev-parse >actual \
-				:0:y/a :0:y/b :0:x/d :1:x/c :2:w/c :3:y/c &&
-			git rev-parse >expect \
-				 O:z/a  O:z/b  O:x/d  O:x/c  O:x/c  O:x/c &&
-			test_cmp expect actual &&
-
-			git hash-object y/c~B^0 >actual &&
-			git rev-parse O:x/c >expect &&
-			test_cmp expect actual
-		fi &&
 
 		echo important >expect &&
 		test_cmp expect y/c
@@ -3425,38 +3310,15 @@ test_expect_success '10c2: Overwrite untracked with dir rename/rename(1to2), oth
 		echo important >y/c &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive A^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: The following untracked working tree files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: The following untracked working tree files would be overwritten by merge" err &&
 
-			git ls-files -s >out &&
+		git ls-files -s >out &&
-			test_line_count = 4 out &&
+		test_line_count = 4 out &&
-			git ls-files -u >out &&
+		git ls-files -u >out &&
-			test_line_count = 0 out &&
+		test_line_count = 0 out &&
-			git ls-files -o >out &&
+		git ls-files -o >out &&
-			test_line_count = 3 out
+		test_line_count = 3 out &&
-		else
-			test_grep "CONFLICT (rename/rename)" out &&
-			test_grep "Refusing to lose untracked file at y/c; adding as y/c~HEAD instead" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 6 out &&
-			git ls-files -u >out &&
-			test_line_count = 3 out &&
-			git ls-files -o >out &&
-			test_line_count = 3 out &&
-
-			git rev-parse >actual \
-				:0:y/a :0:y/b :0:x/d :1:x/c :3:w/c :2:y/c &&
-			git rev-parse >expect \
-				 O:z/a  O:z/b  O:x/d  O:x/c  O:x/c  O:x/c &&
-			test_cmp expect actual &&
-
-			git hash-object y/c~HEAD >actual &&
-			git rev-parse O:x/c >expect &&
-			test_cmp expect actual
-		fi &&
 
 		echo important >expect &&
 		test_cmp expect y/c
@@ -3514,47 +3376,15 @@ test_expect_success '10d: Delete untracked with dir rename/rename(2to1)' '
 		echo important >y/wham &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: The following untracked working tree files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: The following untracked working tree files would be overwritten by merge" err &&
 
-			git ls-files -s >out &&
+		git ls-files -s >out &&
-			test_line_count = 6 out &&
+		test_line_count = 6 out &&
-			git ls-files -u >out &&
+		git ls-files -u >out &&
-			test_line_count = 0 out &&
+		test_line_count = 0 out &&
-			git ls-files -o >out &&
+		git ls-files -o >out &&
-			test_line_count = 3 out
+		test_line_count = 3 out &&
-		else
-			test_grep "CONFLICT (rename/rename)" out &&
-			test_grep "Refusing to lose untracked file at y/wham" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 6 out &&
-			git ls-files -u >out &&
-			test_line_count = 2 out &&
-			git ls-files -o >out &&
-			test_line_count = 3 out &&
-
-			git rev-parse >actual \
-				:0:y/a :0:y/b :0:y/d :0:y/e :2:y/wham :3:y/wham &&
-			git rev-parse >expect \
-				 O:z/a  O:z/b  O:x/d  O:x/e  O:z/c     O:x/f &&
-			test_cmp expect actual &&
-
-			test_must_fail git rev-parse :1:y/wham &&
-
-			# Test that two-way merge in y/wham~merged is as expected
-			git cat-file -p :2:y/wham >expect &&
-			git cat-file -p :3:y/wham >other &&
-			>empty &&
-			test_must_fail git merge-file \
-				-L "HEAD" \
-				-L "" \
-				-L "B^0" \
-				expect empty other &&
-			test_cmp expect y/wham~merged
-		fi &&
 
 		echo important >expect &&
 		test_cmp expect y/wham
@@ -3596,7 +3426,7 @@ test_setup_10e () {
 	)
 }
 
-test_expect_merge_algorithm failure success '10e: Does git complain about untracked file that is not really in the way?' '
+test_expect_success '10e: Does git complain about untracked file that is not really in the way?' '
 	test_setup_10e &&
 	(
 		cd 10e &&
@@ -3687,30 +3517,8 @@ test_expect_success '11a: Avoid losing dirty contents with simple rename' '
 		echo stuff >>z/c &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: Your local changes to the following files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: Your local changes to the following files would be overwritten by merge" err
-		else
-			test_grep "Refusing to lose dirty file at z/c" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 2 out &&
-			git ls-files -u >out &&
-			test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 3 out &&
-
-			git rev-parse >actual \
-				:0:z/a :2:z/c &&
-			git rev-parse >expect \
-				 O:z/a  B:z/b &&
-			test_cmp expect actual &&
-
-			git hash-object z/c~HEAD >actual &&
-			git rev-parse B:z/b >expect &&
-			test_cmp expect actual
-		fi &&
 
 		test_seq 1 10 >expected &&
 		echo stuff >>expected &&
@@ -3766,34 +3574,9 @@ test_expect_success '11b: Avoid losing dirty file involved in directory rename'
 		git checkout A^0 &&
 		echo stuff >>z/c &&
 
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		then
+		test_path_is_missing .git/MERGE_HEAD &&
-			test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
+		test_grep "error: Your local changes to the following files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: Your local changes to the following files would be overwritten by merge" err
-		else
-			git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-			test_grep "Refusing to lose dirty file at z/c" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 3 out &&
-			git ls-files -u >out &&
-			test_line_count = 0 out &&
-			git ls-files -m >out &&
-			test_line_count = 0 out &&
-			git ls-files -o >out &&
-			test_line_count = 3 out &&
-
-			git rev-parse >actual \
-				:0:x/b :0:y/a :0:y/c &&
-			git rev-parse >expect \
-				 O:x/b  O:z/a  B:x/c &&
-			test_cmp expect actual &&
-
-			git hash-object y/c >actual &&
-			git rev-parse B:x/c >expect &&
-			test_cmp expect actual
-		fi &&
 
 		grep -q stuff z/c &&
 		test_seq 1 10 >expected &&
@@ -3850,13 +3633,8 @@ test_expect_success '11c: Avoid losing not-uptodate with rename + D/F conflict'
 		echo stuff >>y/c &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: Your local changes to the following files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: Your local changes to the following files would be overwritten by merge" err
-		else
-			test_grep "following files would be overwritten by merge" err
-		fi &&
 
 		grep -q stuff y/c &&
 		test_seq 1 10 >expected &&
@@ -3924,30 +3702,8 @@ test_expect_success '11d: Avoid losing not-uptodate with rename + D/F conflict'
 		echo stuff >>z/c &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: Your local changes to the following files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: Your local changes to the following files would be overwritten by merge" err
-		else
-			test_grep "Refusing to lose dirty file at z/c" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 4 out &&
-			git ls-files -u >out &&
-			test_line_count = 1 out &&
-			git ls-files -o >out &&
-			test_line_count = 4 out &&
-
-			git rev-parse >actual \
-				:0:x/b :0:y/a :0:y/c/d :3:y/c &&
-			git rev-parse >expect \
-				 O:x/b  O:z/a  B:y/c/d  B:x/c &&
-			test_cmp expect actual &&
-
-			git hash-object y/c~HEAD >actual &&
-			git rev-parse B:x/c >expect &&
-			test_cmp expect actual
-		fi &&
 
 		grep -q stuff z/c &&
 		test_seq 1 10 >expected &&
@@ -4010,39 +3766,8 @@ test_expect_success '11e: Avoid deleting not-uptodate with dir rename/rename(1to
 		echo mods >>y/c &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: Your local changes to the following files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: Your local changes to the following files would be overwritten by merge" err
-		else
-			test_grep "CONFLICT (rename/rename)" out &&
-			test_grep "Refusing to lose dirty file at y/c" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 7 out &&
-			git ls-files -u >out &&
-			test_line_count = 4 out &&
-			git ls-files -o >out &&
-			test_line_count = 3 out &&
-
-			git rev-parse >actual \
-				:0:y/a :0:y/b :0:x/d :1:x/c :2:w/c :2:y/c :3:y/c &&
-			git rev-parse >expect \
-				 O:z/a  O:z/b  O:x/d  O:x/c  O:x/c  A:y/c  O:x/c &&
-			test_cmp expect actual &&
-
-			# See if y/c~merged has expected contents; requires manually
-			# doing the expected file merge
-			git cat-file -p A:y/c >c1 &&
-			git cat-file -p B:z/c >c2 &&
-			>empty &&
-			test_must_fail git merge-file \
-				-L "HEAD" \
-				-L "" \
-				-L "B^0" \
-				c1 empty c2 &&
-			test_cmp c1 y/c~merged
-		fi &&
 
 		echo different >expected &&
 		echo mods >>expected &&
@@ -4099,40 +3824,8 @@ test_expect_success '11f: Avoid deleting not-uptodate with dir rename/rename(2to
 		echo important >>y/wham &&
 
 		test_must_fail git -c merge.directoryRenames=true merge -s recursive B^0 >out 2>err &&
-		if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+		test_path_is_missing .git/MERGE_HEAD &&
-		then
+		test_grep "error: Your local changes to the following files would be overwritten by merge" err &&
-			test_path_is_missing .git/MERGE_HEAD &&
-			test_grep "error: Your local changes to the following files would be overwritten by merge" err
-		else
-			test_grep "CONFLICT (rename/rename)" out &&
-			test_grep "Refusing to lose dirty file at y/wham" out &&
-
-			git ls-files -s >out &&
-			test_line_count = 4 out &&
-			git ls-files -u >out &&
-			test_line_count = 2 out &&
-			git ls-files -o >out &&
-			test_line_count = 3 out &&
-
-			test_must_fail git rev-parse :1:y/wham &&
-
-			git rev-parse >actual \
-				:0:y/a :0:y/b :2:y/wham :3:y/wham &&
-			git rev-parse >expect \
-				 O:z/a  O:z/b  O:x/c     O:x/d &&
-			test_cmp expect actual &&
-
-			# Test that two-way merge in y/wham~merged is as expected
-			git cat-file -p :2:y/wham >expect &&
-			git cat-file -p :3:y/wham >other &&
-			>empty &&
-			test_must_fail git merge-file \
-				-L "HEAD" \
-				-L "" \
-				-L "B^0" \
-				expect empty other &&
-			test_cmp expect y/wham~merged
-		fi &&
 
 		test_seq 1 10 >expected &&
 		echo important >>expected &&
@@ -4267,7 +3960,7 @@ test_setup_12b1 () {
 	)
 }
 
-test_expect_merge_algorithm failure success '12b1: Moving two directory hierarchies into each other' '
+test_expect_success '12b1: Moving two directory hierarchies into each other' '
 	test_setup_12b1 &&
 	(
 		cd 12b1 &&
@@ -4435,7 +4128,7 @@ test_setup_12c1 () {
 	)
 }
 
-test_expect_merge_algorithm failure success '12c1: Moving one directory hierarchy into another w/ content merge' '
+test_expect_success '12c1: Moving one directory hierarchy into another w/ content merge' '
 	test_setup_12c1 &&
 	(
 		cd 12c1 &&
@@ -4797,7 +4490,7 @@ test_setup_12f () {
 	)
 }
 
-test_expect_merge_algorithm failure success '12f: Trivial directory resolve, caching, all kinds of fun' '
+test_expect_success '12f: Trivial directory resolve, caching, all kinds of fun' '
 	test_setup_12f &&
 	(
 		cd 12f &&
@@ -5253,7 +4946,7 @@ test_setup_12l () {
 	)
 }
 
-test_expect_merge_algorithm failure success '12l (B into A): Rename into each other + add/add conflict' '
+test_expect_success '12l (B into A): Rename into each other + add/add conflict' '
 	test_setup_12l BintoA &&
 	(
 		cd 12l_BintoA &&
@@ -5280,7 +4973,7 @@ test_expect_merge_algorithm failure success '12l (B into A): Rename into each ot
 	)
 '
 
-test_expect_merge_algorithm failure success '12l (A into B): Rename into each other + add/add conflict' '
+test_expect_success '12l (A into B): Rename into each other + add/add conflict' '
 	test_setup_12l AintoB &&
 	(
 		cd 12l_AintoB &&
@@ -5348,7 +5041,7 @@ test_setup_12m () {
 	)
 }
 
-test_expect_merge_algorithm failure success '12m: Change parent of renamed-dir to symlink on other side' '
+test_expect_success '12m: Change parent of renamed-dir to symlink on other side' '
 	test_setup_12m &&
 	(
 		cd 12m &&

t/t6424-merge-unrelated-index-changes.sh

@@ -176,9 +176,11 @@ test_expect_success 'merge-recursive, when index==head but head!=HEAD' '
 	# Make index match B
 	git diff C B -- | git apply --cached &&
 	test_when_finished "git clean -fd" &&  # Do not leave untracked around
+	git write-tree >index-before &&
 	# Merge B & F, with B as "head"
 	git merge-recursive A -- B F > out &&
-	test_grep "Already up to date" out
+	git write-tree >index-after &&
+	test_cmp index-before index-after
 '
 
 test_expect_success 'recursive, when file has staged changes not matching HEAD nor what a merge would give' '
@@ -294,10 +296,8 @@ test_expect_success 'with multiple strategies, recursive or ort failure do not e
 	git add a &&
 	git rev-parse :a >expect &&
 
-	sane_unset GIT_TEST_MERGE_ALGORITHM &&
+	test_must_fail git merge -s ort -s octopus C^0 >output 2>&1 &&
-	test_must_fail git merge -s recursive -s ort -s octopus C^0 >output 2>&1 &&
 
-	grep "Trying merge strategy recursive..." output &&
 	grep "Trying merge strategy ort..." output &&
 	grep "Trying merge strategy octopus..." output &&
 	grep "No merge strategy handled the merge." output &&

t/t6426-merge-skip-unneeded-updates.sh

@@ -23,8 +23,6 @@ test_description="merge cases"
 #                     files that might be renamed into each other's paths.)
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-merge.sh
-
 
 ###########################################################################
 # SECTION 1: Cases involving no renames (one side has subset of changes of
@@ -663,7 +661,7 @@ test_setup_4a () {
 #   correct requires doing the merge in-memory first, then realizing that no
 #   updates to the file are necessary, and thus that we can just leave the path
 #   alone.
-test_expect_merge_algorithm failure success '4a: Change on A, change on B subset of A, dirty mods present' '
+test_expect_success '4a: Change on A, change on B subset of A, dirty mods present' '
 	test_setup_4a &&
 	(
 		cd 4a &&

t/t6428-merge-conflicts-sparse.sh

@@ -23,8 +23,6 @@ test_description="merge cases"
 #                     files that might be renamed into each other's paths.)
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-merge.sh
-
 
 # Testcase basic, conflicting changes in 'numerals'
 

t/t6430-merge-recursive.sh

@@ -6,7 +6,6 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-merge.sh
 
 test_expect_success 'setup 1' '
 
@@ -373,9 +372,9 @@ test_expect_success 'merge-recursive d/f conflict result' '
 
 	git ls-files -s >actual &&
 	(
-		echo "100644 $o0 1	a" &&
-		echo "100644 $o1 2	a" &&
 		echo "100644 $o4 0	a/c" &&
+		echo "100644 $o0 1	a~$c1" &&
+		echo "100644 $o1 2	a~$c1" &&
 		echo "100644 $o0 0	b" &&
 		echo "100644 $o0 0	c" &&
 		echo "100644 $o1 0	d/e"
@@ -397,9 +396,9 @@ test_expect_success 'merge-recursive d/f conflict result the other way' '
 
 	git ls-files -s >actual &&
 	(
-		echo "100644 $o0 1	a" &&
-		echo "100644 $o1 3	a" &&
 		echo "100644 $o4 0	a/c" &&
+		echo "100644 $o0 1	a~$c1" &&
+		echo "100644 $o1 3	a~$c1" &&
 		echo "100644 $o0 0	b" &&
 		echo "100644 $o0 0	c" &&
 		echo "100644 $o1 0	d/e"
@@ -424,9 +423,9 @@ test_expect_success 'merge-recursive d/f conflict result' '
 		echo "100644 $o1 0	a" &&
 		echo "100644 $o0 0	b" &&
 		echo "100644 $o0 0	c" &&
-		echo "100644 $o6 3	d" &&
 		echo "100644 $o0 1	d/e" &&
-		echo "100644 $o1 2	d/e"
+		echo "100644 $o1 2	d/e" &&
+		echo "100644 $o6 3	d~$c6"
 	) >expected &&
 	test_cmp expected actual
 
@@ -448,9 +447,9 @@ test_expect_success 'merge-recursive d/f conflict result' '
 		echo "100644 $o1 0	a" &&
 		echo "100644 $o0 0	b" &&
 		echo "100644 $o0 0	c" &&
-		echo "100644 $o6 2	d" &&
 		echo "100644 $o0 1	d/e" &&
-		echo "100644 $o1 3	d/e"
+		echo "100644 $o1 3	d/e" &&
+		echo "100644 $o6 2	d~$c6"
 	) >expected &&
 	test_cmp expected actual
 
@@ -645,7 +644,7 @@ test_expect_success 'merge-recursive copy vs. rename' '
 	test_cmp expected actual
 '
 
-test_expect_merge_algorithm failure success 'merge-recursive rename vs. rename/symlink' '
+test_expect_success 'merge-recursive rename vs. rename/symlink' '
 
 	git checkout -f rename &&
 	git merge rename-ln &&
@@ -696,33 +695,6 @@ test_expect_success 'merging with triple rename across D/F conflict' '
 	git merge other
 '
 
-test_expect_success 'merge-recursive remembers the names of all base trees' '
-	git reset --hard HEAD &&
-
-	# make the index match $c1 so that merge-recursive below does not
-	# fail early
-	git diff --binary HEAD $c1 -- | git apply --cached &&
-
-	# more trees than static slots used by oid_to_hex()
-	for commit in $c0 $c2 $c4 $c5 $c6 $c7
-	do
-		git rev-parse "$commit^{tree}" || return 1
-	done >trees &&
-
-	# ignore the return code; it only fails because the input is weird...
-	test_must_fail git -c merge.verbosity=5 merge-recursive $(cat trees) -- $c1 $c3 >out &&
-
-	# ...but make sure it fails in the expected way
-	test_grep CONFLICT.*rename/rename out &&
-
-	# merge-recursive prints in reverse order, but we do not care
-	sort <trees >expect &&
-	sed -n "s/^virtual //p" out | sort >actual &&
-	test_cmp expect actual &&
-
-	git clean -fd
-'
-
 test_expect_success 'merge-recursive internal merge resolves to the sameness' '
 	git reset --hard HEAD &&
 

t/t6434-merge-recursive-rename-options.sh

@@ -34,7 +34,9 @@ export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 get_expected_stages () {
 	git checkout rename -- $1-new &&
 	git ls-files --stage $1-new >expected-stages-undetected-$1 &&
-	sed "s/ 0	/ 2	/" <expected-stages-undetected-$1 \
+	git ls-tree HEAD^ $1-old >tmp &&
+	git ls-tree HEAD  $1-new >>tmp &&
+	cat tmp | awk '{print $1 " " $3 " " NR "\t" '$1'"-new"}' \
 		>expected-stages-detected-$1 &&
 	git read-tree -u --reset HEAD
 }
@@ -51,11 +53,11 @@ rename_undetected () {
 
 check_common () {
 	git ls-files --stage >stages-actual &&
-	test_line_count = 4 stages-actual
+	test_line_count = $1 stages-actual
 }
 
 check_threshold_0 () {
-	check_common &&
+	check_common 8 &&
 	rename_detected 0 &&
 	rename_detected 1 &&
 	rename_detected 2 &&
@@ -63,7 +65,7 @@ check_threshold_0 () {
 }
 
 check_threshold_1 () {
-	check_common &&
+	check_common 7 &&
 	rename_undetected 0 &&
 	rename_detected 1 &&
 	rename_detected 2 &&
@@ -71,7 +73,7 @@ check_threshold_1 () {
 }
 
 check_threshold_2 () {
-	check_common &&
+	check_common 6 &&
 	rename_undetected 0 &&
 	rename_undetected 1 &&
 	rename_detected 2 &&
@@ -79,7 +81,7 @@ check_threshold_2 () {
 }
 
 check_exact_renames () {
-	check_common &&
+	check_common 5 &&
 	rename_undetected 0 &&
 	rename_undetected 1 &&
 	rename_undetected 2 &&
@@ -87,7 +89,7 @@ check_exact_renames () {
 }
 
 check_no_renames () {
-	check_common &&
+	check_common 4 &&
 	rename_undetected 0 &&
 	rename_undetected 1 &&
 	rename_undetected 2 &&

t/t6436-merge-overwrite.sh

@@ -101,19 +101,10 @@ test_expect_success 'will not overwrite unstaged changes in renamed file' '
 	git mv c1.c other.c &&
 	git commit -m rename &&
 	cp important other.c &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_must_fail git merge c1a >out 2>err &&
-	then
+	test_grep "would be overwritten by merge" err &&
-		test_must_fail git merge c1a >out 2>err &&
+	test_cmp important other.c &&
-		test_grep "would be overwritten by merge" err &&
+	test_path_is_missing .git/MERGE_HEAD
-		test_cmp important other.c &&
-		test_path_is_missing .git/MERGE_HEAD
-	else
-		test_must_fail git merge c1a >out &&
-		test_grep "Refusing to lose dirty file at other.c" out &&
-		test_path_is_file other.c~HEAD &&
-		test $(git hash-object other.c~HEAD) = $(git rev-parse c1a:c1.c) &&
-		test_cmp important other.c
-	fi
 '
 
 test_expect_success 'will not overwrite untracked subtree' '

t/t6437-submodule-merge.sh

@@ -9,7 +9,6 @@ GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB=1
 export GIT_TEST_FATAL_REGISTER_SUBMODULE_ODB
 
 . ./test-lib.sh
-. "$TEST_DIRECTORY"/lib-merge.sh
 
 #
 # history
@@ -110,14 +109,10 @@ test_expect_success 'merging should conflict for non fast-forward' '
 	test_when_finished "git -C merge-search reset --hard" &&
 	(cd merge-search &&
 	 git checkout -b test-nonforward-a b &&
-	  if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	 test_must_fail git merge c 2>actual &&
-	  then
+	 sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
-		test_must_fail git merge c 2>actual &&
+	 grep "$sub_expect" actual
-		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
+	 )
-		grep "$sub_expect" actual
-	  else
-		test_must_fail git merge c 2> actual
-	  fi)
 '
 
 test_expect_success 'finish setup for merge-search' '
@@ -151,14 +146,9 @@ test_expect_success 'merging should conflict for non fast-forward (resolution ex
 	 git checkout -b test-nonforward-b b &&
 	 (cd sub &&
 	  git rev-parse --short sub-d > ../expect) &&
-	  if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	  test_must_fail git merge c >actual 2>sub-actual &&
-	  then
+	  sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
-		test_must_fail git merge c >actual 2>sub-actual &&
+	  grep "$sub_expect" sub-actual &&
-		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
-		grep "$sub_expect" sub-actual
-	  else
-		test_must_fail git merge c 2> actual
-	  fi &&
 	 grep $(cat expect) actual > /dev/null &&
 	 git reset --hard)
 '
@@ -169,23 +159,12 @@ test_expect_success 'merging should fail for ambiguous common parent' '
 	(cd sub &&
 	 git checkout -b ambiguous sub-b &&
 	 git merge sub-c &&
-	 if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	 git rev-parse --short sub-d >../expect1 &&
-	 then
+	 git rev-parse --short ambiguous >../expect2
-		git rev-parse --short sub-d >../expect1 &&
-		git rev-parse --short ambiguous >../expect2
-	 else
-		git rev-parse sub-d > ../expect1 &&
-		git rev-parse ambiguous > ../expect2
-	 fi
 	 ) &&
-	 if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	test_must_fail git merge c >actual 2>sub-actual &&
-	 then
+	sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
-		test_must_fail git merge c >actual 2>sub-actual &&
+	grep "$sub_expect" sub-actual &&
-		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-c)" &&
-		grep "$sub_expect" sub-actual
-	 else
-		test_must_fail git merge c 2> actual
-	 fi &&
 	grep $(cat expect1) actual > /dev/null &&
 	grep $(cat expect2) actual > /dev/null &&
 	git reset --hard)
@@ -227,11 +206,9 @@ test_expect_success 'merging should fail for changes that are backwards' '
 
 	git checkout -b test-backward e &&
 	test_must_fail git merge f 2>actual &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-d)" &&
-    then
+	grep "$sub_expect" actual
-		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short sub-d)" &&
+	)
-		grep "$sub_expect" actual
-	fi)
 '
 
 
@@ -358,7 +335,7 @@ test_expect_success 'setup file/submodule conflict' '
 	)
 '
 
-test_expect_merge_algorithm failure success 'file/submodule conflict' '
+test_expect_success 'file/submodule conflict' '
 	test_when_finished "git -C file-submodule reset --hard" &&
 	(
 		cd file-submodule &&
@@ -467,7 +444,7 @@ test_expect_failure 'directory/submodule conflict; keep submodule clean' '
 	)
 '
 
-test_expect_merge_algorithm failure success !FAIL_PREREQS 'directory/submodule conflict; should not treat submodule files as untracked or in the way' '
+test_expect_success !FAIL_PREREQS 'directory/submodule conflict; should not treat submodule files as untracked or in the way' '
 	test_when_finished "git -C directory-submodule/path reset --hard" &&
 	test_when_finished "git -C directory-submodule reset --hard" &&
 	(
@@ -535,11 +512,9 @@ test_expect_success 'merging should fail with no merge base' '
 	git add sub &&
 	git commit -m "b" &&
 	test_must_fail git merge a 2>actual &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short HEAD^1)" &&
-    then
+	grep "$sub_expect" actual
-		sub_expect="go to submodule (sub), and either merge commit $(git -C sub rev-parse --short HEAD^1)" &&
+	)
-		grep "$sub_expect" actual
-	fi)
 '
 
 test_done

t/t6438-submodule-directory-file-conflicts.sh

@@ -12,11 +12,6 @@ test_submodule_switch "merge --ff"
 
 test_submodule_switch "merge --ff-only"
 
-if test "$GIT_TEST_MERGE_ALGORITHM" != ort
-then
-	KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1
-	KNOWN_FAILURE_NOFF_MERGE_ATTEMPTS_TO_MERGE_REMOVED_SUBMODULE_FILES=1
-fi
 test_submodule_switch "merge --no-ff"
 
 test_done

t/t6439-merge-co-error-msgs.sh

@@ -47,7 +47,7 @@ test_expect_success 'untracked files overwritten by merge (fast and non-fast for
 		export GIT_MERGE_VERBOSITY &&
 		test_must_fail git merge branch 2>out2
 	) &&
-	echo "Merge with strategy ${GIT_TEST_MERGE_ALGORITHM:-ort} failed." >>expect &&
+	echo "Merge with strategy ort failed." >>expect &&
 	test_cmp out2 expect &&
 	git reset --hard HEAD^
 '

t/t7402-submodule-rebase.sh

@@ -124,11 +124,8 @@ test_expect_success 'rebasing submodule that should conflict' '
 		echo "160000 $(git rev-parse HEAD) 3	submodule"
 	) >expect &&
 	test_cmp expect actual &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	sub_expect="go to submodule (submodule), and either merge commit $(git -C submodule rev-parse --short HEAD^0)" &&
-    then
+	grep "$sub_expect" actual_output
-		sub_expect="go to submodule (submodule), and either merge commit $(git -C submodule rev-parse --short HEAD^0)" &&
-		grep "$sub_expect" actual_output
-	fi
 '
 
 test_done

t/t7602-merge-octopus-many.sh

@@ -77,12 +77,9 @@ Merge made by the 'recursive' strategy.
 EOF
 
 test_expect_success 'merge reduces irrelevant remote heads' '
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	mv expected expected.tmp &&
-	then
+	sed s/recursive/ort/ expected.tmp >expected &&
-		mv expected expected.tmp &&
+	rm expected.tmp &&
-		sed s/recursive/ort/ expected.tmp >expected &&
-		rm expected.tmp
-	fi &&
 	GIT_MERGE_VERBOSITY=0 git merge c4 c5 >actual &&
 	test_cmp expected actual
 '

t/t7610-mergetool.sh

@@ -535,14 +535,9 @@ test_expect_success 'file vs modified submodule' '
 	yes "" | git mergetool file1 file2 spaced\ name subdir/file3 &&
 	yes "" | git mergetool both &&
 	yes "d" | git mergetool file11 file12 &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	yes "c" | git mergetool submod~HEAD &&
-	then
+	git rm submod &&
-		yes "c" | git mergetool submod~HEAD &&
+	git mv submod~HEAD submod &&
-		git rm submod &&
-		git mv submod~HEAD submod
-	else
-		yes "l" | git mergetool submod
-	fi &&
 	git submodule update -N &&
 	echo "not a submodule" >expect &&
 	test_cmp expect submod &&
@@ -559,15 +554,10 @@ test_expect_success 'file vs modified submodule' '
 	yes "" | git mergetool file1 file2 spaced\ name subdir/file3 &&
 	yes "" | git mergetool both &&
 	yes "d" | git mergetool file11 file12 &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	mv submod submod.orig &&
-	then
+	git rm --cached submod &&
-		mv submod submod.orig &&
+	yes "c" | git mergetool submod~test19 &&
-		git rm --cached submod &&
+	git mv submod~test19 submod &&
-		yes "c" | git mergetool submod~test19 &&
-		git mv submod~test19 submod
-	else
-		yes "r" | git mergetool submod
-	fi &&
 	test -d submod.orig &&
 	git submodule update -N &&
 	echo "not a submodule" >expect &&
@@ -585,10 +575,7 @@ test_expect_success 'file vs modified submodule' '
 	yes "" | git mergetool both &&
 	yes "d" | git mergetool file11 file12 &&
 	yes "l" | git mergetool submod &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	yes "d" | git mergetool submod~test19 &&
-	then
-		yes "d" | git mergetool submod~test19
-	fi &&
 	echo "main submodule" >expect &&
 	test_cmp expect submod/bar &&
 	git submodule update -N &&
@@ -686,14 +673,9 @@ test_expect_success 'directory vs modified submodule' '
 	test_must_fail git merge main &&
 	test -n "$(git ls-files -u)" &&
 	test ! -e submod.orig &&
-	if test "$GIT_TEST_MERGE_ALGORITHM" = ort
+	yes "r" | git mergetool submod~main &&
-	then
+	git mv submod submod.orig &&
-		yes "r" | git mergetool submod~main &&
+	git mv submod~main submod &&
-		git mv submod submod.orig &&
-		git mv submod~main submod
-	else
-		yes "r" | git mergetool submod
-	fi &&
 	test -d submod.orig &&
 	echo "not a submodule" >expect &&
 	test_cmp expect submod.orig/file16 &&

t/t7615-diff-algo-with-mergy-operations.sh

@@ -22,8 +22,6 @@ test_expect_success 'setup' '
 	git tag c2
 '
 
-GIT_TEST_MERGE_ALGORITHM=recursive
-
 test_expect_success 'merge c2 to c1 with recursive merge strategy fails with the current default myers diff algorithm' '
 	git reset --hard c1 &&
 	test_must_fail git merge -s recursive -Xdiff-algorithm=myers c2

t/test-lib.sh

@@ -540,8 +540,6 @@ GIT_DEFAULT_HASH="${GIT_TEST_DEFAULT_HASH:-sha1}"
 export GIT_DEFAULT_HASH
 GIT_DEFAULT_REF_FORMAT="${GIT_TEST_DEFAULT_REF_FORMAT:-files}"
 export GIT_DEFAULT_REF_FORMAT
-GIT_TEST_MERGE_ALGORITHM="${GIT_TEST_MERGE_ALGORITHM:-ort}"
-export GIT_TEST_MERGE_ALGORITHM
 
 # Tests using GIT_TRACE typically don't want <timestamp> <file>:<line> output
 GIT_TRACE_BARE=1