anno: Stop segmentation violation on `-number 0'.

If atoi(3) returned zero, either because `0' was given or the number
could not be parsed, then the error message dereferenced an invalid
pointer.  Found when trying to increase coverage with check_exit.

diff --git a/uip/anno.c b/uip/anno.c
index 5376930..c6446fc 100644 (file)
--- a/uip/anno.c
+++ b/uip/anno.c
@@ -169,7 +169,7 @@ main (int argc, char **argv)
                            number = -1;
 
                        else if (!(number = atoi(*argp)))
                            number = -1;
 
                        else if (!(number = atoi(*argp)))

-                           adios (NULL, "missing argument to %s", argp[-2]);
+                           adios (NULL, "missing argument to %s", argp[-1]);

 
                        argp++;
                    }
 
                        argp++;
                    }