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>

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