apply: check git diffs for missing old filenames

2c93286a (fix "git apply --index ..." not to deref NULL) added a check
for git patches missing a +++ line, preventing a segfault.  Check for
missing --- lines as well, and add a test for each case.

Found by Vegard Nossum using AFL.

Original-patch-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/apply.c b/apply.c
index 705cf562f07098aafcd9f6e27105d2105714751f..1c0bcd737ee339832eaaaf38e26c21cd6036c5fe 100644 (file)
--- a/apply.c
+++ b/apply.c
@@ -1585,7 +1585,8 @@ static int find_header(struct apply_state *state,
                                patch->old_name = xstrdup(patch->def_name);
                                patch->new_name = xstrdup(patch->def_name);
                        }
-                       if (!patch->is_delete && !patch->new_name) {
+                       if ((!patch->new_name && !patch->is_delete) ||
+                           (!patch->old_name && !patch->is_new)) {
                                error(_("git diff header lacks filename information "
                                             "(line %d)"), state->linenr);
                                return -128;

diff --git a/t/t4133-apply-filenames.sh b/t/t4133-apply-filenames.sh
index 2ecb4216b7179ef836836d90a5f76f5e4349ca23..c5ed3b17c4a1196e154affc346b5fd3d4e0a7abf 100755 (executable)
--- a/t/t4133-apply-filenames.sh
+++ b/t/t4133-apply-filenames.sh
@@ -35,4 +35,28 @@ test_expect_success 'apply diff with inconsistent filenames in headers' '
        test_i18ngrep "inconsistent old filename" err
 '
 
+test_expect_success 'apply diff with new filename missing from headers' '
+       cat >missing_new_filename.diff <<-\EOF &&
+       diff --git a/f b/f
+       index 0000000..d00491f
+       --- a/f
+       @@ -0,0 +1 @@
+       +1
+       EOF
+       test_must_fail git apply missing_new_filename.diff 2>err &&
+       test_i18ngrep "lacks filename information" err
+'
+
+test_expect_success 'apply diff with old filename missing from headers' '
+       cat >missing_old_filename.diff <<-\EOF &&
+       diff --git a/f b/f
+       index d00491f..0000000
+       +++ b/f
+       @@ -1 +0,0 @@
+       -1
+       EOF
+       test_must_fail git apply missing_old_filename.diff 2>err &&
+       test_i18ngrep "lacks filename information" err
+'
+
 test_done