v2revision: add --except option

Documentation/git-rev-parse.txt, contrib/completion/git-completion.bash, revision.c, revision.h, t/t6112-rev-list-except.sh

diff --git a/Documentation/git-rev-parse.txt b/Documentation/git-rev-parse.txt
index 2b126c0..fe5cc6b 100644
--- a/Documentation/git-rev-parse.txt
+++ b/Documentation/git-rev-parse.txt
@@ -110,6 +110,12 @@ can be used.
 	strip '{caret}' prefix from the object names that already have
 	one.
 
+--except::
+	Skip the following object names. For example:
+	'--branches --except master' will show all the branches, except master.
+	This differs from --not in that --except will still show the object, if
+	they are referenced by another object name.
+
 --symbolic::
 	Usually the object names are output in SHA-1 form (with
 	possible '{caret}' prefix); this option makes them output in a
diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 5da920e..aed8c12 100644
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -1386,7 +1386,7 @@ _git_ls_tree ()
 
 # Options that go well for log, shortlog and gitk
 __git_log_common_options="
-	--not --all
+	--not --except --all
 	--branches --tags --remotes
 	--first-parent --merges --no-merges
 	--max-count=
diff --git a/revision.c b/revision.c
index 84ccc05..a7664dd 100644
--- a/revision.c
+++ b/revision.c
@@ -1984,6 +1984,8 @@ static int handle_revision_pseudo_opt(const char *submodule,
 		handle_reflog(revs, *flags);
 	} else if (!strcmp(arg, "--not")) {
 		*flags ^= UNINTERESTING | BOTTOM;
+	} else if (!strcmp(arg, "--except")) {
+		*flags |= SKIP;
 	} else if (!strcmp(arg, "--no-walk")) {
 		revs->no_walk = REVISION_WALK_NO_WALK_SORTED;
 	} else if (!prefixcmp(arg, "--no-walk=")) {
@@ -2573,24 +2575,72 @@ void reset_revision_walk(void)
 	clear_object_flags(SEEN | ADDED | SHOWN);
 }
 
+static int refcmp(const char *a, const char *b)
+{
+	a = prettify_refname(a);
+	if (*a == '^')
+		a++;
+	b = prettify_refname(b);
+	if (*b == '^')
+		b++;
+	return strcmp(a, b);
+}
+
+static int recalculate_flag(struct rev_info *revs, unsigned char *sha1, const char *name)
+{
+	int flags = 0;
+	int i;
+	for (i = 0; i < revs->cmdline.nr; i++) {
+		struct object *object;
+		struct rev_cmdline_entry *ce;
+		ce = &revs->cmdline.rev[i];
+		object = ce->item;
+		while (object->type == OBJ_TAG) {
+			struct tag *tag = (struct tag *) object;
+			if (!tag->tagged)
+				continue;
+			object = parse_object(tag->tagged->sha1);
+			if (!object)
+				continue;
+		}
+		if (hashcmp(object->sha1, sha1))
+			continue;
+		if (!strcmp(ce->name, name))
+			continue;
+		flags |= ce->flags;
+	}
+	return flags;
+}
+
 int prepare_revision_walk(struct rev_info *revs)
 {
 	int nr = revs->pending.nr;
 	struct object_array_entry *e, *list;
 	struct commit_list **next = &revs->commits;
+	int i;
 
 	e = list = revs->pending.objects;
 	revs->pending.nr = 0;
 	revs->pending.alloc = 0;
 	revs->pending.objects = NULL;
 	while (--nr >= 0) {
-		struct commit *commit = handle_commit(revs, e->item, e->name);
+		struct commit *commit;
+		for (i = 0; i < revs->cmdline.nr; i++) {
+			struct rev_cmdline_entry *ce;
+			ce = &revs->cmdline.rev[i];
+			if ((ce->flags & SKIP) && !refcmp(ce->name, e->name)) {
+				e->item->flags = recalculate_flag(revs, e->item->sha1, ce->name);
+				goto next;
+			}
+		}
+		commit = handle_commit(revs, e->item, e->name);
 		if (commit) {
 			if (!(commit->object.flags & SEEN)) {
 				commit->object.flags |= SEEN;
 				next = commit_list_append(commit, next);
 			}
 		}
+next:
 		e++;
 	}
 	if (!revs->leak_pending)
diff --git a/revision.h b/revision.h
index 95859ba..89f5037 100644
--- a/revision.h
+++ b/revision.h
@@ -17,7 +17,8 @@
 #define SYMMETRIC_LEFT	(1u<<8)
 #define PATCHSAME	(1u<<9)
 #define BOTTOM		(1u<<10)
-#define ALL_REV_FLAGS	((1u<<11)-1)
+#define SKIP		(1u<<11)
+#define ALL_REV_FLAGS	((1u<<12)-1)
 
 #define DECORATE_SHORT_REFS	1
 #define DECORATE_FULL_REFS	2
diff --git a/t/t6112-rev-list-except.sh b/t/t6112-rev-list-except.sh
new file mode 100755
index 0000000..a40a641
--- /dev/null
+++ b/t/t6112-rev-list-except.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+
+test_description='test for rev-list --except'
+
+. ./test-lib.sh
+
+test_expect_success 'setup' '
+
+	echo one > content &&
+	git add content &&
+	git commit -m one &&
+	git checkout -b test master &&
+	echo two > content &&
+	git commit -a -m two &&
+	git checkout -b merge master &&
+	git merge test
+'
+
+test_expect_success 'rev-list --except' '
+
+	git rev-list --topo-order --branches --except merge > actual &&
+	git rev-list --topo-order test > expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rev-list --except with extra' '
+
+	echo three > content &&
+	git commit -a -m three &&
+	git rev-list --topo-order --branches --except merge > actual &&
+	git rev-list --topo-order test > expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rev-list --except with full ref' '
+
+	git rev-list --topo-order --branches --except refs/heads/merge > actual &&
+	git rev-list --topo-order test > expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rev-list --except and --not' '
+
+	git rev-list --topo-order test --not master --except master > actual &&
+	git rev-list --topo-order test > expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'rev-list --except and --not with proper flags' '
+
+	git checkout -b maint master &&
+	git checkout -b next test &&
+	echo four > content &&
+	git commit -a -m four &&
+	git rev-list --topo-order next --not master maint --except maint > actual &&
+	git rev-list --topo-order next --not master > expect &&
+	test_cmp expect actual
+'
+
+test_done