fix in the parser for callbacks in the middle of a word

src/runtime/c/pgf/parser.c

@@ -1616,6 +1616,8 @@ pgf_parsing_symbol(PgfParsing* ps, PgfItem* item, PgfSymbol sym)
 				/* This is the first time when we encounter this 
 				 * literal category so we must call the callback */
 
+				bool match = false;
+				if (!ps->before->needs_bind) {
 					PgfLiteralCallback* callback =
 						gu_map_get(ps->callbacks,
 								   parg->ccat->cnccat, 
@@ -1647,8 +1649,12 @@ pgf_parsing_symbol(PgfParsing* ps, PgfItem* item, PgfSymbol sym)
 								pgf_new_parse_state(ps, offset, BIND_NONE,
 													item->inside_prob+item->conts->outside_prob);
 							gu_buf_heap_push(state->agenda, pgf_item_prob_order, &item);
+							match = true;
 						}
-				} else {
+					}
+				}
+
+				if (!match) {
 					pgf_item_free(ps, item);
 				}
 			} else {