Depending on which spec you read, field widths and precisions in %s may be
counted either in bytes or characters. Our code was assuming bytes, which
is wrong at least for glibc's implementation, and in any case libc might
have a different idea of the prevailing encoding than we do. Hence, for
portable results we must avoid using anything more complex than just "%s"
unless the string to be printed is known to be all-ASCII.
This patch fixes the cases I could find, including the psql formatting
failure reported by Hernan Gonzalez. In HEAD only, I also added comments
to some places where it appears safe to continue using "%.*s".
refers to itself (directly or indirectly). Instead, print a message when
recursion is detected, and don't expand the repeated reference. Per bug
#5448 from Francis Markham.
Back-patch to 8.0. Although the issue exists in 7.4 as well, it seems
impractical to fix there because of the lack of any state stack that
could be used to track active expansions.
field of the WAL record. The previous coding always wrote to the main fork,
resulting in data corruption if the page was meant to go into a non-default
fork.
At present, the only operation that can produce such WAL records is
ALTER TABLE/INDEX SET TABLESPACE when executed with archive_mode = on.
Data corruption would be observed on standby slaves, and could occur on the
master as well if a database crash and recovery occurred after committing
the ALTER and before the next checkpoint. Per report from Gordon Shannon.
Back-patch to 8.4; the problem doesn't exist in earlier branches because
we didn't have a concept of multiple relation forks then.
returns EINVAL for an existing shared memory segment. Although it's not
terribly sensible, that behavior does meet the POSIX spec because EINVAL
is the appropriate error code when the existing segment is smaller than the
requested size, and the spec explicitly disclaims any particular ordering of
error checks. Moreover, it does in fact happen on OS X and probably other
BSD-derived kernels. (We were able to talk NetBSD into changing their code,
but purging that behavior from the wild completely seems unlikely to happen.)
We need to distinguish collision with a pre-existing segment from invalid size
request in order to behave sensibly, so it's worth some extra code here to get
it right. Per report from Gavin Kistner and subsequent investigation.
Back-patch to all supported versions, since any of them could get used
with a kernel having the debatable behavior.
memory if the result had zero rows, and also if there was any sort of error
while converting the result tuples into Python data. Reported and partially
fixed by Andres Freund.
Back-patch to all supported versions. Note: I haven't tested the 7.4 fix.
7.4's configure check for python is so obsolete it doesn't work on my
current machines :-(. The logic change is pretty straightforward though.
This change was previously committed to HEAD, but the consensus seems to be
in favor of back-patching it. I'm only backpatching as far as 8.3.X, however,
because it's not clear to me to what degree this advice applies to older
branches, and in any case our first advice to anyone attempting to tune those
versions is likely to be "upgrade".
reload and rotation signals, and a helper thread reads messages from the
pipe and writes them to the log file. However, server code isn't generally
thread-safe, so if both try to do e.g palloc()/pfree() at the same time,
bad things will happen. To fix that, use a critical section (which is like
a mutex) to enforce that only one the threads are active at a time.
the SELECT query in \copy (SELECT ...) commands. This is unnecessary and
breaks numeric literals, as seen in bug #5411 from Vitalii Tymchyshyn.
This change has already been made in passing in HEAD; backpatch to 8.2
through 8.4 (earlier releases don't have COPY (SELECT ...) at all).
even when the expression is a query that returns no rows.
So far as I can tell, the only caller that actually fails when a garbage
OID is returned is exec_stmt_case(), which is new in 8.4 --- in all other
cases, we might make a useless trip through casting logic, but we won't
fail since the isnull flag will be set. Hence, backpatch only to 8.4,
just in case there are apps out there that aren't expecting an error to
be thrown if the query returns more or less than one column. (Which seems
unlikely, since the error would be thrown if the query ever did return a
row; but it's possible there's some never-exercised code out there.)
Per report from Mario Splivalo.
relcache reload works. In the patched code, a relcache entry in process of
being rebuilt doesn't get unhooked from the relcache hash table; which means
that if a cache flush occurs due to sinval queue overrun while we're
rebuilding it, the entry could get blown away by RelationCacheInvalidate,
resulting in crash or misbehavior. Fix by ensuring that an entry being
rebuilt has positive refcount, so it won't be seen as a target for removal
if a cache flush occurs. (This will mean that the entry gets rebuilt twice
in such a scenario, but that's okay.) It appears that the problem can only
arise within a transaction that has previously reassigned the relfilenode of
a pre-existing table, via TRUNCATE or a similar operation. Per bug #5412
from Rusty Conover.
Back-patch to 8.2, same as the patch that introduced the problem.
I think that the failure can't actually occur in 8.2, since it lacks the
rd_newRelfilenodeSubid optimization, but let's make it work like the later
branches anyway.
Patch by Heikki, slightly editorialized on by me.
Windows timezone name where the information in the registry is
incomplete, instead of aborting.
This fixes cases when the registry information is incomplete for
a timezone that is alphabetically before the one that is in use.
Per report from Alexander Forschner
Windows, thanks to a feature in CRT called Parameter Validation.
Backpatch to 8.2, which is the oldest version supported on Windows. In
8.2 and 8.3 also backpatch the earlier change to use DEVNULL instead of
NULL_DEV #define for a /dev/null-like device. NULL_DEV was hard-coded to
"/dev/null" regardless of platform, which didn't work on Windows, while
DEVNULL works on all platforms. Restarting syslogger didn't work on
Windows on versions 8.3 and below because of that.
constraint exclusion on an inheritance set that is the target of an UPDATE
or DELETE query. Per gripe from Marc Cousin. Back-patch to 8.4 where
the feature was introduced.
unsatisfiable query, such as indexcol && empty_array. It should return -1
to tell GIN no scan is required; but silly typo disabled the logic for that,
resulting in unnecessary "GIN indexes do not support whole-index scans" error.
Per bug report from Jeff Trout.
Back-patch to 8.3 where the logic was introduced.
by a superuser -- "ALTER USER f RESET setting" already disallows removing such a
setting.
Apply the same treatment to ALTER DATABASE d RESET ALL when run by a database
owner that's not superuser.
so that we won't try to attach any context printouts to messages that get
emitted while exiting. Per report from Dennis Koegel, the context functions
won't necessarily work after we've started shutting down the backend, and it
seems possible that debug_query_string could be pointing at freed storage
as well. The context information doesn't seem particularly relevant to
such messages anyway, so there's little lost by suppressing it.
Back-patch to all supported branches. I can only demonstrate a crash with
log_disconnections messages back to 8.1, but the risk seems real in 8.0 and
before anyway.
catalog entries via SearchSysCache and related operations. Although, at the
time that these callbacks are called by elog.c, we have not officially aborted
the current transaction, it still seems rather risky to initiate any new
catalog fetches. In all these cases the needed information is readily
available in the caller and so it's just a matter of a bit of extra notation
to pass it to the callback.
Per crash report from Dennis Koegel. I've concluded that the real fix for
his problem is to clear the error context stack at entry to proc_exit, but
it still seems like a good idea to make the callbacks a bit less fragile
for other cases.
Backpatch to 8.4. We could go further back, but the patch doesn't apply
cleanly. In the absence of proof that this fixes something and isn't just
paranoia, I'm not going to expend the effort.
because InRedo was cleared before recovery_end_command was executed.
Also, always take ControlFileLock when reading checkpoint location for
%r. That didn't matter before, but in 8.4 bgwriter is active during
recovery and can modify the control file concurrently.
corner cases that come up in certain timezones (apparently, only those with
lots and lots of distinct TZ transition rules, as far as I can gather from
a quick scan of their archives). Per suggestion from Jeevan Chalke.
Back-patch to 8.4. Possibly we need to push this into earlier releases
as well, but I'm hesitant to update them to the 64-bit tzcode without
more thought and testing.
The latter is considered unwarranted chumminess with the implementation,
and can lead to crashes with recent Perl versions.
Report and fix by Tim Bunce. Back-patch to all versions containing the
questionable coding pattern.
--single-transaction are both used and the failure happens in commit,
e.g. failed deferred trigger. Also properly free BEGIN/COMMIT result
structures from --single-transaction.
Per report from Dominic Bevacqua
when warning about column-level privileges. This is more useful than before
and makes the apparent duplication complained of by Piyush Newe not so
duplicate. Also fix lack of quote marks in a related message text.
Back-patch to 8.4, where column-level privileges were introduced.
Stephen Frost
unless (1) the @ isn't quoted and (2) the filename isn't empty. This guards
against unexpectedly treating usernames or other strings in "flat files"
as inclusion requests, as seen in a recent trouble report from Ed L.
The empty-filename case would be guaranteed to misbehave anyway, because our
subsequent path-munging behavior results in trying to read the directory
containing the current input file.
I think this might finally explain the report at
http://archives.postgresql.org/pgsql-bugs/2004-05/msg00132.php
of a crash after printing "authentication file token too long, skipping",
since I was able to duplicate that message (though not a crash) on a
platform where stdio doesn't refuse to read directories. We never got
far in investigating that problem, but now I'm suspicious that the trigger
condition was an @ in the flat password file.
Back-patch to all active branches since the problem can be demonstrated in all
branches except HEAD. The test case, creating a user named "@", doesn't cause
a problem in HEAD since we got rid of the flat password file. Nonetheless it
seems like a good idea to not consider quoted @ as a file inclusion spec,
so I changed HEAD too.
set ferror() but never set feof(). This is known to be the case for recent
glibc when trying to read a directory as a file, and might be true for other
platforms/cases too. Per report from Ed L. (There is more that we ought to
do about his report, but this is one easily identifiable issue.)
in versions >= 8.3). The core code is more robust and efficient than what
was there before, and this also reduces risks involved in swapping different
libxml error handler settings.
Before 8.3, there is still some risk of problems if add-on modules such as
Perl invoke libxml without setting their own error handler. Given the lack
of reports I'm not sure there's a risk in practice, so I didn't take the
step of actually duplicating the core code into older contrib/xml2 branches.
Instead I just tweaked the existing code to ensure it didn't leave a dangling
pointer to short-lived memory when throwing an error.
