sort_in_topological_order(): avoid setting a commit flag

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

commit.c

@@ -428,8 +428,7 @@ 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 */
@@ -438,7 +437,7 @@ 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;
 		}
@@ -456,7 +455,7 @@ 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;
 	}
 
@@ -478,15 +477,15 @@ 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;
 
 			/*
 			 * parents are only enqueued for emission
 			 * when all their children have been emitted thereby
 			 * guaranteeing topological order.
 			 */
-			if (!--parent->indegree) {
+			if (--parent->indegree == 1) {
 				if (!lifo)
 					insert_by_date(parent, &work);
 				else
@@ -497,7 +496,7 @@ 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;
+		commit->indegree = 0;
 		*pptr = work_item;
 		pptr = &work_item->next;
 	}

revision.h

@@ -10,7 +10,6 @@
 #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.. */
 
 struct rev_info;
 struct log_info;

t/t3202-show-branch-octopus.sh

@@ -0,0 +1,59 @@
+#!/bin/sh
+
+test_description='test show-branch with more than 8 heads'
+
+. ./test-lib.sh
+
+numbers="1 2 3 4 5 6 7 8 9 10"
+
+test_expect_success 'setup' '
+
+	> file &&
+	git add file &&
+	test_tick &&
+	git commit -m initial &&
+
+	for i in $numbers
+	do
+		git checkout -b branch$i master &&
+		> file$i &&
+		git add file$i &&
+		test_tick &&
+		git commit -m branch$i || break
+	done
+
+'
+
+cat > expect << EOF
+! [branch1] branch1
+ ! [branch2] branch2
+  ! [branch3] branch3
+   ! [branch4] branch4
+    ! [branch5] branch5
+     ! [branch6] branch6
+      ! [branch7] branch7
+       ! [branch8] branch8
+        ! [branch9] branch9
+         * [branch10] branch10
+----------
+         * [branch10] branch10
+        +  [branch9] branch9
+       +   [branch8] branch8
+      +    [branch7] branch7
+     +     [branch6] branch6
+    +      [branch5] branch5
+   +       [branch4] branch4
+  +        [branch3] branch3
+ +         [branch2] branch2
++          [branch1] branch1
++++++++++* [branch10^] initial
+EOF
+
+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
+
+'
+
+test_done