34ad3aedb0
tsquery's GETQUERY() macro is only safe to apply to a tsquery that is known non-empty; otherwise it gives a pointer to garbage. Before commit 5a617d75d, ts_headline() avoided this pitfall, but only in a very indirect, nonobvious way. (hlCover could not reach its TS_execute call, because if the query contains no lexemes then hlFirstIndex would surely return -1.) After that commit, it fell into the trap, resulting in weird errors such as "unrecognized operator" and/or valgrind complaints. In HEAD, fix this by not calling TS_execute_locations() at all for an empty query. In the back branches, add a defensive check to hlCover() --- that's not fixing any live bug, but I judge the code a bit too fragile as-is. Also, both mark_hl_fragments() and mark_hl_words() were careless about the possibility of empty search text: in the cases where no match has been found, they'd end up telling mark_fragment() to mark from word indexes 0 to 0 inclusive, even when there is no word 0. This is harmless since we over-allocated the prs->words array, but it does annoy valgrind. Fix so that the end index is -1 and thus mark_fragment() will do nothing in such cases. Bottom line is that this fixes a live bug in HEAD, but in the back branches it's only getting rid of a valgrind nitpick. Back-patch anyway. Per report from Alexander Lakhin. Discussion: https://postgr.es/m/c27f642d-020b-01ff-ae61-086af287c4fd@gmail.com
PostgreSQL Database Management System ===================================== This directory contains the source code distribution of the PostgreSQL database management system. PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download/ See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.