- update to 1.4.19:
* New QueryParser::FLAG_NO_POSITIONS flag. With this flag enabled, any query
operations which would use positional information are replaced by the nearest
equivalent which doesn't (so phrase searches, NEAR and ADJ will result in
OP_AND). This is intended to replace the automatic conversion of OP_PHRASE,
etc to OP_AND when a database has no positional information, which will no
longer happen in the release series after 1.4.
* Give a compile error for code which adds a Database to WritableDatabase.
Prior to 1.4.19, this compiled and effectively created a "black-hole" shard
which quietly discarded any changes made to it.
In 1.4.19 it's still possible to perform this operation by assigning the
WritableDatabase to a Database first, which is harder to fix. This case
throws an exception on git master where it's easier to address.
* Fix TermIterator::skip_to() with sharded databases which sometimes was
failing to advance all the way to the requested term. Uncovered while
addressing warning from GCC's -Wduplicated-cond, reported by dcb in #816.
* Clamp edit distance to one less than the length of the word we've been asked
to correct, which makes the algorithm we use more efficient. We already
require suggestion to have at least one character in common, so the only
change to suggestions is we'll no longer suggest corrections which are
twice as long or longer even if the edit distance would allow it, which
seems like an improvement in itself.
* Minor optimisation expanding wildcards.
* PostingIterator::get_description(): For an all-docs iterator on a glass
database, get_description() would call get_docid() which isn't valid to
do once the iterator has reached the end.
* Expand allterms test coverage.
* Fetch wdf upper bound from postlist which avoids an extra postlist table
cursor seek per weighted query term, and also means we now use a per-shard
wdf upper bound for local shards which will in typically give a tighter