[PATCH] blame: prevent a segv when -L given start > EOF

[Jay Soffian <jaysoffian@gmail.com>]

blame would segv if given -L <lineno> with <lineno> past the end of the file.
While we're fixing the bug, add test cases for an invalid <start> when called
as -L <start>,<end> or -L<start>.

Signed-off-by: Jay Soffian <jaysoffian@gmail.com>
---
bottom is start and top is end, which seems backwards to me, but alas, it is
what it is. :-)

 builtin-blame.c  |    2 +-
 t/t8003-blame.sh |    8 ++++++++
 2 files changed, 9 insertions(+), 1 deletions(-)

diff --git a/builtin-blame.c b/builtin-blame.c
index 6408ec8..10f7eac 100644
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -2433,7 +2433,7 @@ parse_done:
 	if (top < 1)
 		top = lno;
 	bottom--;
-	if (lno < top)
+	if (lno < top || lno < bottom)
 		die("file %s has only %lu lines", path, lno);
 
 	ent = xcalloc(1, sizeof(*ent));
diff --git a/t/t8003-blame.sh b/t/t8003-blame.sh
index ad834f2..4a8db74 100755
--- a/t/t8003-blame.sh
+++ b/t/t8003-blame.sh
@@ -157,4 +157,12 @@ EOF
   git --no-pager blame $COMMIT -- uno >/dev/null
 '
 
+test_expect_success 'blame -L with invalid start' '
+	test_must_fail git blame -L5 tres 2>&1 | grep "has only 2 lines"
+'
+
+test_expect_success 'blame -L with invalid end' '
+	git blame -L1,5 tres 2>&1 | grep "has only 2 lines"
+'
+
 test_done
-- 
1.7.0.rc1.200.g9c1f9