[PATCH 2/2] sort_in_topological_order(): avoid setting a commit flag

[Johannes Schindelin <Johannes.Schindelin@gmx.de>]

We used to set the TOPOSORT flag of commits during the topological
sorting, but we can just as well use the member "indegree" for it:
indegree is now incremented by 1 in the cases where the commit used
to have the TOPOSORT flag.

This is the same behavior as before, since indegree could not be
non-zero when TOPOSORT was unset.

Incidentally, this fixes the bug in show-branch where the 8th column
was not shown: show-branch sorts the commits in topological order,
assuming that all the commit flags are available for show-branch's
private matters.

But this was not true: TOPOSORT was identical to the flag corresponding
to the 8th ref.  So the flags for the 8th column were unset by the
topological sorting.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---

	This is another late-night patch done by yours-truly.  However,
	I tried extra hard to make sure that every occurrence of
	indegree was properly changed, and I am pretty certain that
	the reasoning with the unset TOPOSORT is correct.

	But please check (I know, not necessary to ask for extra review
	for my patches,	but nevertheless).

 commit.c                       |   13 ++++++-------
 revision.h                     |    3 +--
 t/t3202-show-branch-octopus.sh |    2 +-
 3 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/commit.c b/commit.c
index 5148ec5..9dacfb8 100644
--- a/commit.c
+++ b/commit.c
@@ -436,8 +436,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
 	/* Mark them and clear the indegree */
 	for (next = orig; next; next = next->next) {
 		struct commit *commit = next->item;
-		commit->object.flags |= TOPOSORT;
-		commit->indegree = 0;
+		commit->indegree = 1;
 	}
 
 	/* update the indegree */
@@ -446,7 +445,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
 		while (parents) {
 			struct commit *parent = parents->item;
 
-			if (parent->object.flags & TOPOSORT)
+			if (parent->indegree)
 				parent->indegree++;
 			parents = parents->next;
 		}
@@ -464,7 +463,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
 	for (next = orig; next; next = next->next) {
 		struct commit *commit = next->item;
 
-		if (!commit->indegree)
+		if (commit->indegree == 1)
 			insert = &commit_list_insert(commit, insert)->next;
 	}
 
@@ -486,7 +485,7 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
 		for (parents = commit->parents; parents ; parents = parents->next) {
 			struct commit *parent=parents->item;
 
-			if (!(parent->object.flags & TOPOSORT))
+			if (!parent->indegree)
 				continue;
 
 			/*
@@ -494,7 +493,8 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
 			 * when all their children have been emitted thereby
 			 * guaranteeing topological order.
 			 */
-			if (!--parent->indegree) {
+			if (--parent->indegree == 1) {
+				parent->indegree = 0;
 				if (!lifo)
 					insert_by_date(parent, &work);
 				else
@@ -505,7 +505,6 @@ void sort_in_topological_order(struct commit_list ** list, int lifo)
 		 * work_item is a commit all of whose children
 		 * have already been emitted. we can emit it now.
 		 */
-		commit->object.flags &= ~TOPOSORT;
 		*pptr = work_item;
 		pptr = &work_item->next;
 	}
diff --git a/revision.h b/revision.h
index fa68c65..f64e8ce 100644
--- a/revision.h
+++ b/revision.h
@@ -12,8 +12,7 @@
 #define CHILD_SHOWN	(1u<<6)
 #define ADDED		(1u<<7)	/* Parents already parsed and added? */
 #define SYMMETRIC_LEFT	(1u<<8)
-#define TOPOSORT	(1u<<9)	/* In the active toposort list.. */
-#define ALL_REV_FLAGS	((1u<<10)-1)
+#define ALL_REV_FLAGS	((1u<<9)-1)
 
 struct rev_info;
 struct log_info;
diff --git a/t/t3202-show-branch-octopus.sh b/t/t3202-show-branch-octopus.sh
index 8d50c23..7fe4a6e 100755
--- a/t/t3202-show-branch-octopus.sh
+++ b/t/t3202-show-branch-octopus.sh
@@ -49,7 +49,7 @@ cat > expect << EOF
 +++++++++* [branch10^] initial
 EOF
 
-test_expect_failure 'show-branch with more than 8 branches' '
+test_expect_success 'show-branch with more than 8 branches' '
 
 	git show-branch $(for i in $numbers; do echo branch$i; done) > out &&
 	test_cmp expect out
-- 
1.6.0.rc0.22.gf2096d.dirty