Fix a potential crash when a non-regular file is present in an

includedir.  Fixes bz #452

plugins/sudoers/toke.c

@@ -3355,6 +3355,7 @@ switch_dir(struct include_stack *stack, char *dirpath)
 	}
 	if (stat(path, &sb) != 0 || !S_ISREG(sb.st_mode)) {
 	    efree(path);
+	    path = NULL;
 	    continue;
 	}
 	pl = malloc(sizeof(*pl));

plugins/sudoers/toke.l

@@ -656,6 +656,7 @@ switch_dir(struct include_stack *stack, char *dirpath)
 	}
 	if (stat(path, &sb) != 0 || !S_ISREG(sb.st_mode)) {
 	    efree(path);
+	    path = NULL;
 	    continue;
 	}
 	pl = malloc(sizeof(*pl));