fix the word completion in the C runtime

src/runtime/c/pgf/parser.c

@@ -1232,6 +1232,7 @@ pgf_parsing_add_transition(PgfParsing* ps, PgfToken tok, PgfItem* item)
 		if (gu_string_is_prefix(ps->prefix, tok)) {
 			ps->tp = gu_new(PgfTokenProb, ps->out_pool);
 			ps->tp->tok  = tok;
+			ps->tp->cat  = item->conts->ccat->cnccat->abscat->name;
 			ps->tp->prob = item->inside_prob + item->conts->outside_prob;
 		}
 	} else {