shared.c: avoid SEGFAULT when checking for binary buffers

Before calling buffer_is_binary() we need to verify that the buffer
is valid.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/shared.c b/shared.c
index dbb84d8..cce0af4 100644
--- a/shared.c
+++ b/shared.c
@@ -266,18 +266,18 @@ int cgit_diff_files(const unsigned char *old_sha1,
 	xdemitcb_t emit_cb;
 
 	if (!load_mmfile(&file1, old_sha1) || !load_mmfile(&file2, new_sha1))
 		return 1;
 
 	*old_size = file1.size;
 	*new_size = file2.size;
 
-	if (buffer_is_binary(file1.ptr, file1.size) ||
-	    buffer_is_binary(file2.ptr, file2.size)) {
+	if ((file1.ptr && buffer_is_binary(file1.ptr, file1.size)) ||
+	    (file2.ptr && buffer_is_binary(file2.ptr, file2.size))) {
 		*binary = 1;
 		return 0;
 	}
 
 	memset(&diff_params, 0, sizeof(diff_params));
 	memset(&emit_params, 0, sizeof(emit_params));
 	memset(&emit_cb, 0, sizeof(emit_cb));
 	diff_params.flags = XDF_NEED_MINIMAL;