1 files changed, 5 insertions, 0 deletions
diff --git a/lib/str.c b/lib/str.c
index 074bdb1..5bf95ec 100644
--- a/lib/str.c
+++ b/lib/str.c
@@ -705,6 +705,11 @@ char *normalize_space(char *s) {
     int add_whitespace = 0;
     char *result = s;
     char *tmp;
+
+    if (s == NULL) {
+        return NULL;
+    }
+
     if ((tmp = calloc(strlen(s) + 1, sizeof(char))) == NULL) {
         perror("could not allocate memory for temporary string");
         return NULL;