rev-parse: introduce --exclude=<glob> to tame wildcards

Teach "rev-parse" the same "I'm going to glob, but omit the ones
that match these patterns" feature as "rev-list".

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-rev-parse.txt

@@ -155,6 +155,20 @@ shown.  If the pattern does not contain a globbing character (`?`,
 	character (`?`, `*`, or `[`), it is turned into a prefix
 	match by appending `/*`.
 
+--exclude=<glob-pattern>::
+	Do not include refs matching '<glob-pattern>' that the next `--all`,
+	`--branches`, `--tags`, `--remotes`, or `--glob` would otherwise
+	consider. Repetitions of this option accumulate exclusion patterns
+	up to the next `--all`, `--branches`, `--tags`, `--remotes`, or
+	`--glob` option (other options or arguments do not clear
+	accumlated patterns).
++
+The patterns given should not begin with `refs/heads`, `refs/tags`, or
+`refs/remotes` when applied to `--branches`, `--tags`, or `--remotes`,
+respectively, and they must begin with `refs/` when applied to `--glob`
+or `--all`. If a trailing '/{asterisk}' is intended, it must be given
+explicitly.
+
 --show-toplevel::
 	Show the absolute path of the top-level directory.
 

builtin/rev-parse.c

@@ -9,6 +9,8 @@
 #include "quote.h"
 #include "builtin.h"
 #include "parse-options.h"
+#include "diff.h"
+#include "revision.h"
 
 #define DO_REVS		1
 #define DO_NOREV	2
@@ -30,6 +32,8 @@ static int abbrev_ref;
 static int abbrev_ref_strict;
 static int output_sq;
 
+static struct string_list *ref_excludes;
+
 /*
  * Some arguments are relevant "revision" arguments,
  * others are about output format or other details.
@@ -185,6 +189,8 @@ static int show_default(void)
 
 static int show_reference(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
+	if (ref_excluded(ref_excludes, refname))
+		return 0;
 	show_rev(NORMAL, sha1, refname);
 	return 0;
 }
@@ -633,32 +639,43 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 			if (!prefixcmp(arg, "--branches=")) {
 				for_each_glob_ref_in(show_reference, arg + 11,
 					"refs/heads/", NULL);
+				clear_ref_exclusion(&ref_excludes);
 				continue;
 			}
 			if (!strcmp(arg, "--branches")) {
 				for_each_branch_ref(show_reference, NULL);
+				clear_ref_exclusion(&ref_excludes);
 				continue;
 			}
 			if (!prefixcmp(arg, "--tags=")) {
 				for_each_glob_ref_in(show_reference, arg + 7,
 					"refs/tags/", NULL);
+				clear_ref_exclusion(&ref_excludes);
 				continue;
 			}
 			if (!strcmp(arg, "--tags")) {
 				for_each_tag_ref(show_reference, NULL);
+				clear_ref_exclusion(&ref_excludes);
 				continue;
 			}
 			if (!prefixcmp(arg, "--glob=")) {
 				for_each_glob_ref(show_reference, arg + 7, NULL);
+				clear_ref_exclusion(&ref_excludes);
 				continue;
 			}
 			if (!prefixcmp(arg, "--remotes=")) {
 				for_each_glob_ref_in(show_reference, arg + 10,
 					"refs/remotes/", NULL);
+				clear_ref_exclusion(&ref_excludes);
 				continue;
 			}
 			if (!strcmp(arg, "--remotes")) {
 				for_each_remote_ref(show_reference, NULL);
+				clear_ref_exclusion(&ref_excludes);
+				continue;
+			}
+			if (!prefixcmp(arg, "--exclude=")) {
+				add_ref_exclusion(&ref_excludes, arg + 10);
 				continue;
 			}
 			if (!strcmp(arg, "--show-toplevel")) {

t/t6018-rev-list-glob.sh

@@ -129,6 +129,18 @@ test_expect_success 'rev-parse --remotes=foo' '
 
 '
 
+test_expect_success 'rev-parse --exclude with --branches' '
+	compare rev-parse "--exclude=*/* --branches" "master someref subspace-x"
+'
+
+test_expect_success 'rev-parse --exclude with --all' '
+	compare rev-parse "--exclude=refs/remotes/* --all" "--branches --tags"
+'
+
+test_expect_success 'rev-parse accumulates multiple --exclude' '
+	compare rev-parse "--exclude=refs/remotes/* --exclude=refs/tags/* --all" --branches
+'
+
 test_expect_success 'rev-list --glob=refs/heads/subspace/*' '
 
 	compare rev-list "subspace/one subspace/two" "--glob=refs/heads/subspace/*"