kunit: string-stream: Don't create a fragment for empty strings

If the result of the formatted string is an empty string just return
instead of creating an empty fragment.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
index cc32743c1171f8eb3e18129d77283733995ae05d..ed24d86af9f5e3b4eece9ee44f3e1d5e78355e4f 100644 (file)
--- a/lib/kunit/string-stream.c
+++ b/lib/kunit/string-stream.c
@@ -50,11 +50,17 @@ int string_stream_vadd(struct string_stream *stream,
        /* Make a copy because `vsnprintf` could change it */
        va_copy(args_for_counting, args);
 
-       /* Need space for null byte. */
-       len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
+       /* Evaluate length of formatted string */
+       len = vsnprintf(NULL, 0, fmt, args_for_counting);
 
        va_end(args_for_counting);
 
+       if (len == 0)
+               return 0;
+
+       /* Need space for null byte. */
+       len++;
+
        frag_container = alloc_string_stream_fragment(stream->test,
                                                      len,
                                                      stream->gfp);