Log Message:
Update to 1.2.17. From the changelog:

API:
* Enquire::set_sort_by_relevance_then_value() and
  Enquire::set_sort_by_relevance_then_key(): Fix sense of reverse parameter.
  Reported by "boomboo" on IRC.
* BM25Weight: Fix case where (k1 == 0 || b == 0) but k2 != 0.  Reported by
  "boomboo" on IRC.
* Unicode::tolower(): Fix to give correct results for U+01C5, U+01C8, U+01CB,
  and U+01F2 (previously these were left unchanged).
* PositionIterator,PostingIterator,TermIterator,ValueIterator: Don't segfault
  if skip_to() or check() is called on an iterator which is already at_end().
  Reported by David Bremner.
* ValueCountMatchSpy: get_description() on a default-constructed
  ValueCountMatchSpy object no longer fails when xapian-core is built with
  --enable-log.
* ValueCountMatchSpy: get_total() on a default-constructed ValueCountMatchSpy
  object now returns 0 rather than segfaulting.

testsuite:
* Automatically probe for and hook in eatmydata to the testsuite using the
  wrapper script it now includes.
* Fix apitest to build when brass, chert or flint are disabled.
* If -v/--verbose is specified more than once to a test program, show the
  diagnostic output for passing tests as well as failing/skipped ones.
* queryparsertest: Change qp_scale1 to time 5 repetitions of the large query to
  help average out variations.
* queryparsertest: Add test coverage for explicit synonym of a term with a
  prefix (e.g. ~foo:search).
* apitest: Remove code from registry* testcases which tries to test the
  consequences of throwing an exception from a destructor - it's complex to
  ensure we don't leak memory while doing this (it seems GCC doesn't release
  the object in this case, but clang does), and it's generally frowned upon,
  plus C++11 makes destructors noexcept by default.
* Fix "make check" to actually removed cached databases first, as is
  intended.

brass backend:
* Fix handling of invalid block sizes passed to Xapian::Brass::open() - the
  size gets fixed as documented, but the uncorrected size was passed to the
  base file (and abort() was called if 0 was passed).
* Validate "dir_end" when reading a block.  (fixes #592)
* When moving a cursor on a read-only table, check if the block we want is in
  the internal cursor.  We already do this for a writable table, as it is
  necessary for correctness, but it's a cheap check and may avoid asking the
  OS for a block we actually already have.
* Correctly report the database as closed rather than 'Bad file descriptor'
  in certain cases.
* Reuse a cursor for reading values from valuestreams rather than creating
  a new one each time.  This can dramatically reduce the number of blocks
  redundantly reread when sorting by value.  The rereads will generally get
  served from VM cache, but there's still an overhead to that.

chert backend:
* Fix handling of invalid block sizes passed to Xapian::Chert::open() - the
  size gets fixed as documented, but the uncorrected size was passed to the
  base file (and abort() was called if 0 was passed).
* Validate "dir_end" when reading a block.  (fixes #592)
* When moving a cursor on a read-only table, check if the block we want is in
  the internal cursor.  We already do this for a writable table, as it is
  necessary for correctness, but it's a cheap check and may avoid asking the
  OS for a block we actually already have.
* Correctly report the database as closed rather than 'Bad file descriptor'
  in certain cases.
* Reuse a cursor for reading values from valuestreams rather than creating
  a new one each time.  This can dramatically reduce the number of blocks
  redundantly reread when sorting by value.  The rereads will generally get
  served from VM cache, but there's still an overhead to that.

flint backend:
* Fix handling of invalid block sizes passed to Xapian::Flint::open() - the
  size gets fixed as documented, but the uncorrected size was passed to the
  base file (and abort() was called if 0 was passed).
* Validate "dir_end" when reading a block.  (fixes #592)
* When moving a cursor on a read-only table, check if the block we want is in
  the internal cursor.  We already do this for a writable table, as it is
  necessary for correctness, but it's a cheap check and may avoid asking the
  OS for a block we actually already have.
* Correctly report the database as closed rather than 'Bad file descriptor'
  in certain cases.

build system:
* configure: Improve reporting of GCC version.
* Use -no-fast-install on platforms where -no-install causes libtool to emit a
  warning.
* docs/Makefile.am: Fix handling of MAINTAINER_NO_DOCS.
* Include UnicodeData.txt and the script to generate the unicode tables from
  it.
* Compress source tarballs with xz instead of gzip.
* Split XAPIAN_LIBS out of XAPIAN_LDFLAGS so that -l flags for libraries
  configure detects are needed appear after -L flags specified by the user
  that may be needed to find such libraries.  (fixes#626)
* XO_LIB_XAPIAN now handles the user specifying a relative path in
  XAPIAN_CONFIG, e.g.: "./configure \ 
XAPIAN_CONFIG=../xapian-core/xapian-config"
* Adjust XO_LIB_XAPIAN to strip _gitNNN suffix from snapshot versions.
* configure: Handle git snapshot naming when calculating REVISION.
* configure: Enable -fshow-column for GCC - things like vim's quickfix mode
  will then jump to the appropriate column for a compiler error or warning, not
  just the appropriate line.
* configure: Report GCC version in configure output.

documentation:
* postingsource.rst: Clarify a couple of points (reported by "vHanda" \ 
on IRC).
* The API documentation shipped with the release is now generated with
  doxygen 1.8.5 instead of 1.5.9, which is most evident in the different
  HTML styling newer doxygen uses.
* Document how Utf8Iterator handles invalid UTF-8 in API documentation.
* Improve how descriptions of deprecated features appear in the API
  documentation.
* docs/remote_protocol.rst: Correct error in documentation of REPLY_DOCDATA
  message.
* docs/overview.rst: Correct documentation for how to specify "prog" remote
  databases in stub files.
* Direct users to git in preference to SVN - we'll be switching entirely in
  the near future.

portability:
* Protect the ValueIterator::check() method against Mac OS X SDK headers
  which define a check() macro.
* Fix warning from xlC compiler.
* Avoid use of grep -e in configure, as /usr/bin/grep on Solaris doesn't
  support -e.
* Fix check for flags which might be needed for ANSI mode for compilers called
  'cxx'.
* configure: Improve handling of Sun's C++ compiler - trick libtool into not
  adding -library=Cstd, and prefer -library=stdcxx4 if supported.  Explicitly
  add -library=Crun which seems to be required, even though the documentation
  suggests otherwise.
* configure: clang doesn't support -Wstrict-null-sentinel or -Wlogical-op, so
  don't pass it these options.
* Fix build errors and warnings with mingw.
* Suppress "unused local typedef" warnings from GCC 4.8.
* If the compiler supports C++11, use static_assert to implement
  CompileTimeAssert.
* tests/zlib-vg.c: Fix two warnings when compiled with clang.
* Fix failure when built with -D_GLIBCXX_DEBUG - we were modifying the top()
  element of a heap before calling pop(), such that the heap comparison
  operation (which is called when -D_GLIBCXX_DEBUG is on to verify the heap is
  valid) would read off the end of the data.  In a normal build, this issue
  would likely never manifest.
* configure: When generating ABI compatibility checks in xapian/version.h, pass
  $CXXFLAGS and $CPPFLAGS to $CXXCPP as they could contain options which affect
  the ABI (such as -fabi-version for GCC).  (Fixes #622)
* Microsoft GUIDs in binary form have reversed byte order in the first three
  components compared to standard UUIDs, so the same database would report a
  different UUID on Windows to on other platforms.  We now swap the bytes to
  match the standard order.  With this fix, the UUIDs of existing databases
  will appear to change on Windows (except in rare "palindronic" cases).
* Fix a couple of issues to get Xapian to build and work on AIX.
* common/safeuuid.h: Remove bogus take-address-of from uuid handling code for
  NetBSD and OpenBSD.
* Under cygwin, use cygwin_conv_path() if using a new enough cygwin version,
  rather than the now deprecated cygwin_conv_to_win32_path().  Reported by
  "Haroogan" on the xapian-devel mailing list.
* common/safeuuid.h: Add missing '#include <cstdlib>' and qualify free \ 
with std.
* Fix 'unused label' warning when chert backend is disabled.
* xapian.h: Add check for Wt headers being included before us and defining
  'slots' as a macro - if they are, give a clear error advising how to work
  around this (previously compilation would fail with a confusing error).

tools:
* xapian-chert-update: Fix -b to work rather than always segfaulting (reported
  in http://bugs.debian.org/716484).
* xapian-chert-update: The documented alias --blocksize for -b has never
  actually been supported, so just drop mentions of it from --help and the man
  page.
* xapian-check:
  + Fix chert database check that first docid in each doclength chunk is more
    than the last docid in the previous chunk - previously this didn't actually
    work.
  + Fix database check not to falsely report "position table: Junk after
    position data" whenever there are 7 unused bits (7 is OK, *more* than 7
    isn't).
  + Fix to report block numbers correctly for links within the B-tree.
  + If the METAINFO key is missing, only report it once per table.
  + Fix database consistency checking to always open all the tables at the same
    revision - not doing this could lead to false errors being reported after a
    commit interrupted by the process being killed or the machine crashing.
    Reported by Joey Hess in http://bugs.debian.org/724610

examples:
* quest: Add --check-at-least option.

debug code:
* Fix assertion failure for when an OrPostList decays to an AndPostList - the
  ordering of the subqueries by estimated termfreq may not be the same as it
  was when the OrPostList was constructed, as the subqueries may themselves
  have decayed.  Reported by Michel Pelletier.
* Fix -Wcast-qual warning from GCC 4.7 when configured with --enable-log.