cgit

commit 9afc883297b0d0943e9b358d2299950f33e8e5ed

Author: Lukas Fleischer <cgit@cryptocrack.de>

Avoid null pointer dereference in cgit_print_diff().

When calling cgit_print_diff() with a bad new_rev and a NULL old_rev,
checking for new_rev's parent commit will result in a null pointer
dereference. Returning on an invalid commit before dereferencing fixes
this. Spotted with clang-analyzer.

Signed-off-by: Lukas Fleischer <cgit@cryptocrack.de>
Signed-off-by: Lars Hjemli <hjemli@gmail.com>

 ui-diff.c | 8 ++++++--


diff --git a/ui-diff.c b/ui-diff.c
index a7bc667f799cfd0e167508e90d0f5273d3c90f42..d21541bd4d2b79d19222fc9dd09ae14e70d59e51 100644
--- a/ui-diff.c
+++ b/ui-diff.c
@@ -345,8 +345,10 @@ 		cgit_print_error(fmt("Bad object name: %s", new_rev));
 		return;
 	}
 	commit = lookup_commit_reference(new_rev_sha1);
-	if (!commit || parse_commit(commit))
+	if (!commit || parse_commit(commit)) {
 		cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(new_rev_sha1)));
+		return;
+	}
 
 	if (old_rev)
 		get_sha1(old_rev, old_rev_sha1);
@@ -362,8 +364,10 @@ 			cgit_print_error(fmt("Bad object name: %s", sha1_to_hex(old_rev_sha1)));
 			return;
 		}
 		commit2 = lookup_commit_reference(old_rev_sha1);
-		if (!commit2 || parse_commit(commit2))
+		if (!commit2 || parse_commit(commit2)) {
 			cgit_print_error(fmt("Bad commit: %s", sha1_to_hex(old_rev_sha1)));
+			return;
+		}
 	}
 
 	if ((ctx.qry.ssdiff && !ctx.cfg.ssdiff) || (!ctx.qry.ssdiff && ctx.cfg.ssdiff))