blob/blobmsg: add null pointer checks to the *_for_each_attr functions, fix formatting

[project/libubox.git] / blobmsg.h

diff --git a/blobmsg.h b/blobmsg.h
index 3eeec9b..1e497f7 100644 (file)
--- a/blobmsg.h
+++ b/blobmsg.h
@@ -204,9 +204,10 @@ void blobmsg_printf(struct blob_buf *buf, const char *name, const char *format,
 /* blobmsg to json formatting */
 
 #define blobmsg_for_each_attr(pos, attr, rem) \
-       for (rem = blobmsg_data_len(attr), pos = blobmsg_data(attr); \
-                rem > 0 && (blob_pad_len(pos) <= rem) && \
-                (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
-                rem -= blob_pad_len(pos), pos = blob_next(pos))
+       for (rem = attr ? blobmsg_data_len(attr) : 0, \
+            pos = attr ? blobmsg_data(attr) : 0; \
+            rem > 0 && (blob_pad_len(pos) <= rem) && \
+            (blob_pad_len(pos) >= sizeof(struct blob_attr)); \
+            rem -= blob_pad_len(pos), pos = blob_next(pos))
 
 #endif