API:
* Database::check(): Fix bogus error reports for documents with length zero
due to a new check added in 1.4.6 that the doclength was between the stored
upper and lower bounds, which failed to allow for the lower bound ignoring
documents with length zero (since documents indexed only by boolean terms
aren't involved in weighted searches). Reported by David Bremner.
* Query: Use of Query::MatchAll in multithreaded code causes problems because
the reference counting gets messed up by concurrent updates. Document that
Query(string()) should be used instead of MatchAll in multithreaded code, and
avoid using it in library code. Reported by Germán M. Bravo.
* Stem:
+ Stemming algorithms added for Irish, Lithuanian, Nepali and Tamil.
+ Merge Snowball compiler changes which improve code generation.
+ Merge optimisations to the Arabic and Turkish stemmers.
glass backend:
* A long-lived cursor on a table in a WritableDatabase could get into
an invalid state, which typically resulted in a DatabaseCorruptError
being thrown with the message:
Db block overwritten - are there multiple writers?
But in fact the on-disk database is not corrupted - it's just that
the cursor in memory has got into an inconsistent state. It looks
like we'll always detect the inconsistency before it can cause on-disk
corruption but it's hard to be completely certain.
The bug is in code to rebuild the cursor when the underlying table
changes in ways which require that, which is a fairly rare occurrence
to start with, and only triggers when a block in the cursor has been
released, reallocated, and we tried to load it in the cursor at the
same level - the cursor wrongly assumes it has the current version
of the block.
Reported with a reproducer by Sylvain Taverne. Confirmed by David
Bremner as also fixing a problem in notmuch for which he hadn't managed
to find a reduced reproducer.
