fix a malloc overflow when doing mkd_anchor_format()

mkdio.c

@@ -233,7 +233,7 @@ mkd_anchor_format(char *s, int len, int labelformat, mkd_flag_t *flags)
     int h4anchor = !is_flag_set(flags, MKD_URLENCODEDANCHOR);
     static const unsigned char hexchars[] = "0123456789abcdef";
 
-    needed = labelformat ? (4*len) : len;
+    needed = (labelformat ? (4*len) : len) + 2;	/* +2 for L & \0 */
 
     if ( (res = malloc(needed)) == NULL )
 	return NULL;

toc.c

@@ -28,14 +28,14 @@ mkd_toc(Document *p, char **doc)
     Cstring res;
     int size;
     int first = 1;
-#if 0
+#if HAVE_NAMED_INITIALIZERS
     static mkd_flag_t islabel = { { [IS_LABEL] = 1 } };
 #else
     mkd_flag_t islabel;
 
     mkd_init_flags(&islabel);
-#endif
     set_mkd_flag(&islabel, IS_LABEL);
+#endif
     
     
     if ( !(doc && p && p->ctx) ) return -1;