Prevent error recursion crashes when encoding conversion fails (Tom)
This change extends fixes made in the last two minor releases for
related failure scenarios. The previous fixes were narrowly tailored
for the original problem reports, but we have now recognized that
any error thrown by an encoding conversion function could
potentially lead to infinite recursion while trying to report the
error. The solution therefore is to disable translation and encoding
conversion and report the plain-ASCII form of any error message,
if we find we have gotten into a recursive error reporting situation.
(CVE-2009-0922)
Disallow CREATE CONVERSION with the wrong encodings
for the specified conversion function (Heikki)
This prevents one possible scenario for encoding conversion failure.
The previous change is a backstop to guard against other kinds of
failures in the same area.
Fix xpath() to not modify the path expression unless
necessary, and to make a saner attempt at it when necessary (Andrew)
The SQL standard suggests that xpath should work on data
that is a document fragment, but libxml doesn't support
that, and indeed it's not clear that this is sensible according to the
XPath standard. xpath attempted to work around this
mismatch by modifying both the data and the path expression, but the
modification was buggy and could cause valid searches to fail. Now,
xpath checks whether the data is in fact a well-formed
document, and if so invokes libxml with no change to the
data or path expression. Otherwise, a different modification method
that is somewhat less likely to fail is used.
Note: The new modification method is still not 100% satisfactory, and it
seems likely that no real solution is possible. This patch should
therefore be viewed as a band-aid to keep from breaking existing
applications unnecessarily. It is likely that
PostgreSQL 8.4 will simply reject use of
xpath on data that is not a well-formed document.
Fix core dump when to_char() is given format codes that
are inappropriate for the type of the data argument (Tom)
Fix possible failure in text search when C locale is used with
a multi-byte encoding (Teodor)
Crashes were possible on platforms where wchar_t is narrower
than int; Windows in particular.
Fix extreme inefficiency in text search parser's handling of an
email-like string containing multiple @ characters (Heikki)
Fix planner problem with sub-SELECT in the output list
of a larger subquery (Tom)
The known symptom of this bug is a "failed to locate grouping
columns" error that is dependent on the datatype involved;
but there could be other issues as well.
Fix decompilation of CASE WHEN with an implicit coercion
(Tom)
This mistake could lead to Assert failures in an Assert-enabled build,
or an "unexpected CASE WHEN clause" error message in other
cases, when trying to examine or dump a view.
Fix possible misassignment of the owner of a TOAST table's rowtype (Tom)
If CLUSTER or a rewriting variant of ALTER TABLE
were executed by someone other than the table owner, the
pg_type entry for the table's TOAST table would end up
marked as owned by that someone. This caused no immediate problems,
since the permissions on the TOAST rowtype aren't examined by any
ordinary database operation. However, it could lead to unexpected
failures if one later tried to drop the role that issued the command
(in 8.1 or 8.2), or "owner of data type appears to be invalid"
warnings from pg_dump after having done so (in 8.3).
Change UNLISTEN to exit quickly if the current session has
never executed any LISTEN command (Tom)
Most of the time this is not a particularly useful optimization, but
since DISCARD ALL invokes UNLISTEN, the previous
coding caused a substantial performance problem for applications that
made heavy use of DISCARD ALL.
Fix PL/pgSQL to not treat INTO after INSERT as
an INTO-variables clause anywhere in the string, not only at the start;
in particular, don't fail for INSERT INTO within
CREATE RULE (Tom)
Clean up PL/pgSQL error status variables fully at block exit
(Ashesh Vashi and Dave Page)
This is not a problem for PL/pgSQL itself, but the omission could cause
the PL/pgSQL Debugger to crash while examining the state of a function.
Retry failed calls to CallNamedPipe() on Windows
(Steve Marshall, Magnus)
It appears that this function can sometimes fail transiently;
we previously treated any failure as a hard error, which could
confuse LISTEN/NOTIFY as well as other
operations.
Add MUST (Mauritius Island Summer Time) to the default list
of known timezone abbreviations (Xavier Bugaud)