Avoid NULL strcmp argument

It is possible for format to be NULL (as described in the function signature)
which causes a segmentation fault when it is passed to strcmp. This patch changes
the conditional to short-circuit if format is NULL and only call strcmp otherwise.

diff --git a/backend/ipp.c b/backend/ipp.c
index 6888eff5c5d6b684c0d854e7759525482b91ca75..80f5d125819fae8d29d71e71ebd8df252373d52d 100644 (file)
--- a/backend/ipp.c
+++ b/backend/ipp.c
@@ -2984,7 +2984,7 @@ new_request(
       fputs("DEBUG: Adding all operation/job attributes.\n", stderr);
       adjust_options(num_options, options);
 
-      if (!strcmp(format, "image/pwg-raster") || !strcmp(format, "image/urf"))
+      if (format && (!strcmp(format, "image/pwg-raster") || !strcmp(format, "image/urf")))
         num_options = cupsRemoveOption("copies", num_options, &options);
 
       cupsEncodeOptions2(request, num_options, options, IPP_TAG_OPERATION);