merge-recursive: Make modify/delete handling code reusable

modify/delete and rename/delete share a lot of similarities; we'd like all
the criss-cross and D/F conflict handling specializations to be shared
between the two.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

merge-recursive.c

@@ -992,6 +992,46 @@ static struct merge_file_info merge_file(struct merge_options *o,
 	return merge_file_1(o, &one, &a, &b, branch1, branch2);
 }
 
+static void handle_change_delete(struct merge_options *o,
+				 const char *path,
+				 const unsigned char *o_sha, int o_mode,
+				 const unsigned char *a_sha, int a_mode,
+				 const unsigned char *b_sha, int b_mode,
+				 const char *change, const char *change_past)
+{
+	char *renamed = NULL;
+	if (dir_in_way(path, !o->call_depth)) {
+		renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
+	}
+
+	if (o->call_depth) {
+		/*
+		 * We cannot arbitrarily accept either a_sha or b_sha as
+		 * correct; since there is no true "middle point" between
+		 * them, simply reuse the base version for virtual merge base.
+		 */
+		remove_file_from_cache(path);
+		update_file(o, 0, o_sha, o_mode, renamed ? renamed : path);
+	} else if (!a_sha) {
+		output(o, 1, "CONFLICT (%s/delete): %s deleted in %s "
+		       "and %s in %s. Version %s of %s left in tree%s%s.",
+		       change, path, o->branch1,
+		       change_past, o->branch2, o->branch2, path,
+		       NULL == renamed ? "" : " at ",
+		       NULL == renamed ? "" : renamed);
+		update_file(o, 0, b_sha, b_mode, renamed ? renamed : path);
+	} else {
+		output(o, 1, "CONFLICT (%s/delete): %s deleted in %s "
+		       "and %s in %s. Version %s of %s left in tree%s%s.",
+		       change, path, o->branch2,
+		       change_past, o->branch1, o->branch1, path,
+		       NULL == renamed ? "" : " at ",
+		       NULL == renamed ? "" : renamed);
+		update_file(o, 0, a_sha, a_mode, renamed ? renamed : path);
+	}
+	free(renamed);
+}
+
 static void conflict_rename_delete(struct merge_options *o,
 				   struct diff_filepair *pair,
 				   const char *rename_branch,
@@ -1409,44 +1449,18 @@ error_return:
 	return ret;
 }
 
-static void handle_delete_modify(struct merge_options *o,
+static void handle_modify_delete(struct merge_options *o,
 				 const char *path,
 				 unsigned char *o_sha, int o_mode,
 				 unsigned char *a_sha, int a_mode,
 				 unsigned char *b_sha, int b_mode)
 {
-	char *renamed = NULL;
-	if (dir_in_way(path, !o->call_depth)) {
-		renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
-	}
-
-	if (o->call_depth) {
-		/*
-		 * We cannot arbitrarily accept either a_sha or b_sha as
-		 * correct; since there is no true "middle point" between
-		 * them, simply reuse the base version for virtual merge base.
-		 */
-		remove_file_from_cache(path);
-		update_file(o, 0, o_sha, o_mode, renamed ? renamed : path);
-	} else if (!a_sha) {
-		output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
-		       "and modified in %s. Version %s of %s left in tree%s%s.",
-		       path, o->branch1,
-		       o->branch2, o->branch2, path,
-		       NULL == renamed ? "" : " at ",
-		       NULL == renamed ? "" : renamed);
-		update_file(o, 0, b_sha, b_mode, renamed ? renamed : path);
-	} else {
-		output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
-		       "and modified in %s. Version %s of %s left in tree%s%s.",
-		       path, o->branch2,
-		       o->branch1, o->branch1, path,
-		       NULL == renamed ? "" : " at ",
-		       NULL == renamed ? "" : renamed);
-		update_file(o, 0, a_sha, a_mode, renamed ? renamed : path);
-	}
-	free(renamed);
-
+	handle_change_delete(o,
+			     path,
+			     o_sha, o_mode,
+			     a_sha, a_mode,
+			     b_sha, b_mode,
+			     "modify", "modified");
 }
 
 static int merge_content(struct merge_options *o,
@@ -1612,7 +1626,7 @@ static int process_entry(struct merge_options *o,
 		} else {
 			/* Modify/delete; deleted side may have put a directory in the way */
 			clean_merge = 0;
-			handle_delete_modify(o, path, o_sha, o_mode,
+			handle_modify_delete(o, path, o_sha, o_mode,
 					     a_sha, a_mode, b_sha, b_mode);
 		}
 	} else if ((!o_sha && a_sha && !b_sha) ||

t/t6022-merge-rename.sh

@@ -303,7 +303,7 @@ test_expect_success 'Rename+D/F conflict; renamed file merges but dir in way' '
 	git checkout -q renamed-file-has-no-conflicts^0 &&
 	test_must_fail git merge --strategy=recursive dir-in-way >output &&
 
-	grep "CONFLICT (delete/modify): dir/file-in-the-way" output &&
+	grep "CONFLICT (modify/delete): dir/file-in-the-way" output &&
 	grep "Auto-merging dir" output &&
 	grep "Adding as dir~HEAD instead" output &&
 
@@ -325,7 +325,7 @@ test_expect_success 'Same as previous, but merged other way' '
 	test_must_fail git merge --strategy=recursive renamed-file-has-no-conflicts >output 2>errors &&
 
 	! grep "error: refusing to lose untracked file at" errors &&
-	grep "CONFLICT (delete/modify): dir/file-in-the-way" output &&
+	grep "CONFLICT (modify/delete): dir/file-in-the-way" output &&
 	grep "Auto-merging dir" output &&
 	grep "Adding as dir~renamed-file-has-no-conflicts instead" output &&