[PATCH v2] rev-list: refuse --first-parent combined with --bisect

[Kevin Daudt <me@ikke.info>]

rev-list --bisect is used by git bisect, but never together with
--first-parent. Because rev-list --bisect together with --first-parent
is not handled currently, and even leads to segfaults, refuse to use
both options together.

Signed-off-by: Kevin Daudt <me@ikke.info>
Suggested-by: Junio C. Hamano <gitster@pobox.com>
---
* Changes from v1: Added the missing SP between "if(",
  as per the code guidelines

Thanks for the feedback.

 Documentation/rev-list-options.txt | 3 ++-
 builtin/rev-list.c                 | 3 +++
 t/t6000-rev-list-misc.sh           | 4 ++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt
index 4ed8587..05c3f6d 100644
--- a/Documentation/rev-list-options.txt
+++ b/Documentation/rev-list-options.txt
@@ -123,7 +123,8 @@ parents) and `--max-parents=-1` (negative numbers denote no upper limit).
 	because merges into a topic branch tend to be only about
 	adjusting to updated upstream from time to time, and
 	this option allows you to ignore the individual commits
-	brought in to your history by such a merge.
+	brought in to your history by such a merge. Cannot be
+	combined with --bisect.
 
 --not::
 	Reverses the meaning of the '{caret}' prefix (or lack thereof)
diff --git a/builtin/rev-list.c b/builtin/rev-list.c
index ff84a82..c271e15 100644
--- a/builtin/rev-list.c
+++ b/builtin/rev-list.c
@@ -291,6 +291,9 @@ int cmd_rev_list(int argc, const char **argv, const char *prefix)
 	if (revs.bisect)
 		bisect_list = 1;
 
+	if(revs.first_parent_only && revs.bisect)
+		die(_("--first-parent is incompattible with --bisect"));
+
 	if (DIFF_OPT_TST(&revs.diffopt, QUICK))
 		info.flags |= REV_LIST_QUIET;
 	for (i = 1 ; i < argc; i++) {
diff --git a/t/t6000-rev-list-misc.sh b/t/t6000-rev-list-misc.sh
index 2602086..1f58b46 100755
--- a/t/t6000-rev-list-misc.sh
+++ b/t/t6000-rev-list-misc.sh
@@ -96,4 +96,8 @@ test_expect_success 'rev-list can show index objects' '
 	test_cmp expect actual
 '
 
+test_expect_success '--bisect and --first-parent can not be combined' '
+	test_must_fail git rev-list --bisect --first-parent HEAD
+'
+
 test_done
-- 
2.3.1.184.g97c12a8.dirty