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[PATCH] branch: don't assume the merge filter ref exists

From
Carlos Martín Nieto <cmn@elego.de>
Date
Feb 27, 2012, 15:11 UTC
Message-ID
<1330355513-22351-1-git-send-email-cmn@elego.de>
In-Reply-To
<20120227122609.GA26981@mx.loc>

print_ref_list looks up the merge_filter_ref and assumes that a valid pointer is returned. When the object doesn't exist, it tries to dereference a NULL pointer. This can be the case when git branch --merged is given an argument that isn't a valid commit name.

Check whether the lookup returns a NULL pointer and die with an error if it does. Add a test, while we're at it.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
---

It certainly looks like --merged was only ever supposed to be used with branch names, as it assumed that get_sha1() would catch the errors.

I'm not sure if "bad object" or "invalid object" fits better. "bad object" might have a stronger implication that it exists but is corrupt.

 builtin/branch.c  |    3 +++
 t/t3200-branch.sh |    4 ++++
 2 files changed, 7 insertions(+), 0 deletions(-)
diff --git a/builtin/branch.c b/builtin/branch.c
index cb17bc3..b63d5fe 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -530,6 +530,9 @@ static int print_ref_list(int kinds, int detached, int verbose, int abbrev, stru
 	if (merge_filter != NO_FILTER) {
 		struct commit *filter;
 		filter = lookup_commit_reference_gently(merge_filter_ref, 0);
+		if (!filter)
+			die("bad object %s", sha1_to_hex(merge_filter_ref));
+
 		filter->object.flags |= UNINTERESTING;
 		add_pending_object(&ref_list.revs,
 				   (struct object *) filter, "");
diff --git a/t/t3200-branch.sh b/t/t3200-branch.sh
index dd1aceb..9fe1d8f 100755
--- a/t/t3200-branch.sh
+++ b/t/t3200-branch.sh
@@ -653,4 +653,8 @@ test_expect_success 'refuse --edit-description on unborn branch for now' '
 	)
 '
 
+test_expect_success '--merged catches invalid object names' '
+	test_must_fail git branch --merged 0000000000000000000000000000000000000000
+'
+
 test_done
-- 
1.7.9.rc0
Previous: Bernhard Reutner-FischerNext: Junio C Hamano
Message 2 of 8 in “[BUG] git branch --merged $unknown_checksum segfaults”
  1. Bernhard Reutner-FischerFeb 27, 2012
  2. branch: don't assume the merge filter ref existsCarlos Martín Nieto, Feb 27, 2012
  3. Junio C HamanoFeb 27, 2012
  4. Jeff KingFeb 27, 2012
  5. Junio C HamanoFeb 27, 2012
  6. Jeff KingFeb 27, 2012
  7. Carlos Martín NietoFeb 28, 2012
  8. Junio C HamanoFeb 28, 2012

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