In-depth robustness.

Reported by: clang static analyzer (clang-8)

1 files changed, 1 insertions, 1 deletions

diff --git a/report.c b/report.c
index 5d9abb73..1466802a 100644
--- a/report.c
+++ b/report.c
@@ -362,7 +362,7 @@ report_at_line (FILE *errfp, errnum, file_name, line_number, message, va_alist)
 	static unsigned int old_line_number;
 
 	if (old_line_number == line_number &&
-	    (file_name == old_file_name || !strcmp (old_file_name, file_name)))
+	    (file_name == old_file_name || (old_file_name != NULL && 0 == strcmp (old_file_name, file_name))))
 	    /* Simply return and print nothing.  */
 	    return;