strtok_ws: account for erroneous usage

* if s and last are both NULL then we'll get a fatal error;
  instead of waiting for the segfault, display an error message
  and call abort()

1 files changed, 6 insertions, 1 deletions

diff --git a/src/main.c b/src/main.c
index 4e733c2..1f815e9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -171,8 +171,13 @@ strtok_ws (char *s)
   char *nonws;
   static char *last = NULL;
 
-  if (s)
+  if (s == NULL)
     last = s;
+  else if (last == NULL)
+    {
+      PRINT_ERROR (("strtok_ws() called but not initalized, this is a *BUG*\n"));
+      abort();
+    }
 
   /* skip to first non-whitespace char. */
   while (*last && isspace (*last)) last++;