Peter Eisentraut [Wed, 15 Aug 2018 16:05:46 +0000 (18:05 +0200)]
Change PROCEDURE to FUNCTION in CREATE OPERATOR syntax
Since procedures are now a different thing from functions, change the
CREATE OPERATOR syntax to use FUNCTION in the clause that specifies the
function. PROCEDURE is still accepted for compatibility.
Reported-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
Peter Eisentraut [Wed, 15 Aug 2018 15:01:39 +0000 (17:01 +0200)]
doc: Update uses of the word "procedure"
Historically, the term procedure was used as a synonym for function in
Postgres/PostgreSQL. Now we have procedures as separate objects from
functions, so we need to clean up the documentation to not mix those
terms.
In particular, mentions of "trigger procedures" are changed to "trigger
functions", and access method "support procedures" are changed to
"support functions". (The latter already used FUNCTION in the SQL
syntax anyway.) Also, the terminology in the SPI chapter has been
cleaned up.
A few tests, examples, and code comments are also adjusted to be
consistent with documentation changes, but not everything.
Reported-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Jonathan S. Katz <jonathan.katz@excoventures.com>
Michael Paquier [Wed, 22 Aug 2018 05:21:49 +0000 (14:21 +0900)]
Do not dump identity sequences with excluded parent table
This commit prevents a crash of pg_dump caused by the exclusion of a
table which has identity columns, as the table would be correctly
excluded but not its identity sequence. In order to fix that, identity
sequences are excluded if the parent table is defined as such. Knowing
about such sequences has no meaning without their parent table anyway.
Reported-by: Andy Abelisto
Author: David Rowley Reviewed-by: Peter Eisentraut, Michael Paquier
Discussion: https://postgr.es/m/153479393218.1316.8472285660264976457@wrigleys.postgresql.org
Backpatch-through: 10
Michael Paquier [Wed, 22 Aug 2018 00:41:37 +0000 (09:41 +0900)]
Add regression tests for VACUUM and ANALYZE with relation skips
When a user does not have ownership on a relation, then specific log
messages are generated. This new test suite adds coverage for all the
possible log messages generated, which will be useful to check the
consistency of any refactoring related to ownership checks for relations
vacuumed or analyzed.
Author: Michael Paquier Reviewed-by: Nathan Bossart
Discussion: https://postgr.es/m/20180812222142.GA6097@paquier.xyz
Michael Paquier [Tue, 21 Aug 2018 06:17:13 +0000 (15:17 +0900)]
Fix set of NLS translation issues
While monitoring the code, a couple of issues related to string
translation has showed up:
- Some routines for auto-updatable views return an error string, which
sometimes missed the shot. A comment regarding string translation is
added for each routine to help with future features.
- GSSAPI authentication missed two translations.
- vacuumdb handles non-translated strings.
- GetConfigOptionByNum should translate strings. This part is not
back-patched as after a minor upgrade this could be surprising for
users.
Reported-by: Kyotaro Horiguchi
Author: Kyotaro Horiguchi Reviewed-by: Michael Paquier, Tom Lane
Discussion: https://postgr.es/m/20180810.152131.31921918.horiguchi.kyotaro@lab.ntt.co.jp
Backpatch-through: 9.3
Noah Misch [Sun, 19 Aug 2018 08:12:22 +0000 (01:12 -0700)]
MSVC: Remove any tmp_check directory before running a TAP test suite.
Back-patch to v11, where commit 90627cf98a8e7d0531789391fd798c9bfcc3bc1a
made the GNU make build system do likewise. Without this, when a
typical PostgresNode-using test failed, subsequent runs bailed out with
a "File exists" error.
Improve error messages for CREATE OR REPLACE PROCEDURE
Change the hint to recommend DROP PROCEDURE instead of FUNCTION. Also
make the error message when changing the return type more specific to
the case of procedures.
Reported-by: Jeremy Evans <code@jeremyevans.net> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Tom Lane [Sat, 18 Aug 2018 18:02:35 +0000 (14:02 -0400)]
Doc: remove obsolete advice about manually inserting snprintf into build.
This para is obsolete, first because nobody is using Solaris 7 anymore,
and second because if someone was, configure should catch the snprintf
buffer overrun problem automatically (since commit 9bed827b1), and third
because this is incorrect advice about how to manually force use of
snprintf.c anyway, and has been so at least since commit 3bc6bdf32.
The lack of complaints about it reinforces the conclusion that Solaris 7
no longer exists in the wild; so I don't feel a need to insert correct
advice instead.
Tom Lane [Fri, 17 Aug 2018 21:12:21 +0000 (17:12 -0400)]
Ensure schema qualification in pg_restore DISABLE/ENABLE TRIGGER commands.
Previously, this code blindly followed the common coding pattern of
passing PQserverVersion(AH->connection) as the server-version parameter
of fmtQualifiedId. That works as long as we have a connection; but in
pg_restore with text output, we don't. Instead we got a zero from
PQserverVersion, which fmtQualifiedId interpreted as "server is too old to
have schemas", and so the name went unqualified. That still accidentally
managed to work in many cases, which is probably why this ancient bug went
undetected for so long. It only became obvious in the wake of the changes
to force dump/restore to execute with restricted search_path.
In HEAD/v11, let's deal with this by ripping out fmtQualifiedId's server-
version behavioral dependency, and just making it schema-qualify all the
time. We no longer support pg_dump from servers old enough to need the
ability to omit schema name, let alone restoring to them. (Also, the few
callers outside pg_dump already didn't work with pre-schema servers.)
In older branches, that's not an acceptable solution, so instead just
tweak the DISABLE/ENABLE TRIGGER logic to ensure it will schema-qualify
its output regardless of server version.
Per bug #15338 from Oleg somebody. Back-patch to all supported branches.
Peter Eisentraut [Tue, 17 Jul 2018 07:48:29 +0000 (09:48 +0200)]
InsertPgAttributeTuple() to set attcacheoff
InsertPgAttributeTuple() is the interface between in-memory tuple
descriptors and on-disk pg_attribute, so it makes sense to give it the
job of resetting attcacheoff. This avoids having all the callers having
to do so.
Andrew Gierth [Fri, 17 Aug 2018 14:04:26 +0000 (15:04 +0100)]
Set scan direction appropriately for SubPlans (bug #15336)
When executing a SubPlan in an expression, the EState's direction
field was left alone, resulting in an attempt to execute the subplan
backwards if it was encountered during a backwards scan of a cursor.
Also, though much less likely, it was possible to reach the execution
of an InitPlan while in backwards-scan state.
Repair by saving/restoring estate->es_direction and forcing forward
scan mode in the relevant places.
Backpatch all the way, since this has been broken since 8.3 (prior to
commit c7ff7663e, SubPlans had their own EStates rather than sharing
the parent plan's, so there was no confusion over scan direction).
Per bug #15336 reported by Vladimir Baranoff; analysis and patch by
me, review by Tom Lane.
Tom Lane [Fri, 17 Aug 2018 14:37:59 +0000 (10:37 -0400)]
Fix configure's snprintf test so it exposes HP-UX bug.
Since commit e1d19c902, buildfarm member gharial has been failing with
symptoms indicating that snprintf sometimes returns -1 for buffer
overrun, even though it passes the added configure check. Some
google research suggests that this happens only in limited cases,
such as when the overrun happens partway through a %d item. Adjust
the configure check to exercise it that way. Since I'm now feeling
more paranoid than I was before, also make the test explicitly verify
that the buffer doesn't get physically overrun.
Bruce Momjian [Fri, 17 Aug 2018 14:25:48 +0000 (10:25 -0400)]
pg_upgrade: issue helpful error message for use on standbys
Commit 777e6ddf1723306bd2bf8fe6f804863f459b0323 checked for a shut down
message from a standby and allowed it to continue. This patch reports a
helpful error message in these cases, suggesting to use rsync as
documented.
Tomas Vondra [Thu, 16 Aug 2018 17:56:11 +0000 (19:56 +0200)]
Use the built-in float datatypes to implement geometric types
This patch makes the geometric operators and functions use the exported
function of the float4/float8 datatypes. The main reason of doing so is
to check for underflow and overflow, and to handle NaNs consciously.
The float datatypes consider NaNs values to be equal and greater than
all non-NaN values. This change considers NaNs equal only for equality
operators. The placement operators, contains, overlaps, left/right of
etc. continue to return false when NaNs are involved. We don't need
to worry about them being considered greater than any-NaN because there
aren't any basic comparison operators like less/greater than for the
geometric datatypes.
The changes may be summarised as:
* Check for underflow, overflow and division by zero
* Consider NaN values to be equal
* Return NULL when the distance is NaN for all closest point operators
* Favour not-NaN over NaN where it makes sense
The patch also replaces all occurrences of "double" as "float8". They
are the same, but were used inconsistently in the same file.
Author: Emre Hasegeli Reviewed-by: Kyotaro Horiguchi, Tomas Vondra
Discussion: https://www.postgresql.org/message-id/CAE2gYzxF7-5djV6-cEvqQu-fNsnt%3DEqbOURx7ZDg%2BVv6ZMTWbg%40mail.gmail.com
Tomas Vondra [Thu, 16 Aug 2018 17:55:43 +0000 (19:55 +0200)]
Remove remaining GEODEBUG references from geo_ops.c
Commit a7dc63d904a6044d299aebdf59ad3199b6a9e99d removed most of the
GEODEBUG occurrences, but there were a couple remaining. So remove
them too, to get rid of the macro entirely.
Tom Lane [Thu, 16 Aug 2018 17:01:09 +0000 (13:01 -0400)]
Require a C99-compliant snprintf(), and remove related workarounds.
Since our substitute snprintf now returns a C99-compliant result,
there's no need anymore to have complicated code to cope with pre-C99
behavior. We can just make configure substitute snprintf.c if it finds
that the system snprintf() is pre-C99. (Note: I do not believe that
there are any platforms where this test will trigger that weren't
already being rejected due to our other C99-ish feature requirements for
snprintf. But let's add the check for paranoia's sake.) Then, simplify
the call sites that had logic to cope with the pre-C99 definition.
I also dropped some stuff that was being paranoid about the possibility
of snprintf overrunning the given buffer. The only reports we've ever
heard of that being a problem were for Solaris 7, which is long dead,
and we've sure not heard any reports of these assertions triggering in
a long time. So let's drop that complexity too.
Likewise, drop some code that wasn't trusting snprintf to set errno
when it returns -1. That would be not-per-spec, and again there's
no real reason to believe it is a live issue, especially not for
snprintfs that pass all of configure's feature checks.
Alvaro Herrera [Thu, 16 Aug 2018 15:43:04 +0000 (12:43 -0300)]
Fix executor prune failure when plan already pruned
In a multi-layer partitioning setup, if at plan time all the
sub-partitions are pruned but the intermediate one remains, the executor
later throws a spurious error that there's nothing to prune. That is
correct, but there's no reason to throw an error. Therefore, don't.
Reported-by: Andreas Seltenreich <seltenreich@gmx.de>
Author: David Rowley <david.rowley@2ndquadrant.com>
Discussion: https://postgr.es/m/87in4h98i0.fsf@ansel.ydns.eu
Tomas Vondra [Thu, 16 Aug 2018 14:49:10 +0000 (16:49 +0200)]
Close the file descriptor in ApplyLogicalMappingFile
The function was forgetting to close the file descriptor, resulting
in failures like this:
ERROR: 53000: exceeded maxAllocatedDescs (492) while trying to open
file "pg_logical/mappings/map-4000-4eb-1_60DE1E08-5376b5-537c6b"
LOCATION: OpenTransientFile, fd.c:2161
Simply close the file at the end, and backpatch to 9.4 (where logical
decoding was introduced). While at it, fix a nearby typo.
Andres Freund [Thu, 16 Aug 2018 08:32:05 +0000 (01:32 -0700)]
Try to enable C99 in configure, but do not rely on it (yet).
Based on recent discussion it seems possible that we might start to
rely on more of C99. A prerequisite for that is enabling support for
that on used compilers.
Let's see on which buildfarm members autoconf's AC_PROG_CC_C99() is
sufficient to do so. There's probably at least one member where the
compiler is too old, but that'd probably be OK.
If we go for this permanently we'd likely want to clean out / up a few
other configure tests.
Note this does not touch the msvc build infrastructure, which'd need
separate treatment.
Thomas Munro [Thu, 16 Aug 2018 05:17:30 +0000 (17:17 +1200)]
Improve comment in GetNewObjectId().
The previous comment gave the impression that skipping OIDs before
FirstNormalObjectId was merely an optimization to avoid likely collisions.
In fact other parts of the system have been relying on this threshold to
detect system-created objects since commit 8e18d04d4da, so adjust the
wording.
Author: Thomas Munro Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/CAEepm%3D33JASACeOayr_W3%3DCSjy2jiPxM-k89axu0akFbHdjnjA%40mail.gmail.com
Alvaro Herrera [Wed, 15 Aug 2018 21:09:29 +0000 (18:09 -0300)]
Update FSM on WAL replay of page all-visible/frozen
We aren't very strict about keeping FSM up to date on WAL replay,
because per-page freespace values aren't critical in replicas (can't
write to heap in a replica; and if the replica is promoted, the values
would be updated by VACUUM anyway). However, VACUUM since 9.6 can skip
processing pages marked all-visible or all-frozen, and if such pages are
recorded in FSM with wrong values, those values are blindly propagated
to FSM's upper layers by VACUUM's FreeSpaceMapVacuum. (This rationale
assumes that crashes are not very frequent, because those would cause
outdated FSM to occur in the primary.)
Even when the FSM is outdated in standby, things are not too bad
normally, because, most per-page FSM values will be zero (other than
those propagated with the base-backup that created the standby); only
once the remaining free space is less than 0.2*BLCKSZ the per-page value
is maintained by WAL replay of heap ins/upd/del. However, if
wal_log_hints=on causes complete FSM pages to be propagated to a standby
via full-page images, many too-optimistic per-page values can end up
being registered in the standby.
Incorrect per-page values aren't critical in most cases, since an
inserter that is given a page that doesn't actually contain the claimed
free space will update FSM with the correct value, and retry until it
finds a usable page. However, if there are many such updates to do, an
inserter can spend a long time doing them before a usable page is found;
in a heavily trafficked insert-only table with many concurrent inserters
this has been observed to cause several second stalls, causing visible
application malfunction.
To fix this problem, it seems sufficient to have heap_xlog_visible
(replay of setting all-visible and all-frozen VM bits for a heap page)
update the FSM value for the page being processed. This fixes the
per-page counters together with making the page skippable to vacuum, so
when vacuum does FreeSpaceMapVacuum, the values propagated to FSM upper
layers are the correct ones, avoiding the problem.
While at it, apply the same fix to heap_xlog_clean (replay of tuple
removal by HOT pruning and vacuum). This makes any space freed by the
cleaning available earlier than the next vacuum in the promoted replica.
Backpatch to 9.6, where this problem was diagnosed on an insert-only
table with all-frozen pages, which were introduced as a concept in that
release. Theoretically it could apply with all-visible pages to older
branches, but there's been no report of that and it doesn't backpatch
cleanly anyway.
Tom Lane [Wed, 15 Aug 2018 20:29:31 +0000 (16:29 -0400)]
Clean up assorted misuses of snprintf()'s result value.
Fix a small number of places that were testing the result of snprintf()
but doing so incorrectly. The right test for buffer overrun, per C99,
is "result >= bufsize" not "result > bufsize". Some places were also
checking for failure with "result == -1", but the standard only says
that a negative value is delivered on failure.
(Note that this only makes these places correct if snprintf() delivers
C99-compliant results. But at least now these places are consistent
with all the other places where we assume that.)
Also, make psql_start_test() and isolation_start_test() check for
buffer overrun while constructing their shell commands. There seems
like a higher risk of overrun, with more severe consequences, here
than there is for the individual file paths that are made elsewhere
in the same functions, so this seemed like a worthwhile change.
Also fix guc.c's do_serialize() to initialize errno = 0 before
calling vsnprintf. In principle, this should be unnecessary because
vsnprintf should have set errno if it returns a failure indication ...
but the other two places this coding pattern is cribbed from don't
assume that, so let's be consistent.
These errors are all very old, so back-patch as appropriate. I think
that only the shell command overrun cases are even theoretically
reachable in practice, but there's not much point in erroneous error
checks.
Tom Lane [Wed, 15 Aug 2018 17:21:05 +0000 (13:21 -0400)]
Make snprintf.c follow the C99 standard for snprintf's result value.
C99 says that the result should be the number of bytes that would have
been emitted given a large enough buffer, not the number we actually
were able to put in the buffer. It's time to make our substitute
implementation comply with that. Not doing so results in inefficiency
in buffer-enlargement cases, and also poses a portability hazard for
third-party code that might expect C99-compliant snprintf behavior
within Postgres.
In passing, remove useless tests for str == NULL; neither C99 nor
predecessor standards ever allowed that except when count == 0,
so I see no reason to expend cycles on making that a non-crash case
for this implementation. Also, don't waste a byte in pg_vfprintf's
local I/O buffer; this might have performance benefits by allowing
aligned writes during flushbuffer calls.
Bruce Momjian [Tue, 14 Aug 2018 21:19:02 +0000 (17:19 -0400)]
pg_upgrade: fix shutdown check for standby servers
Commit 244142d32afd02e7408a2ef1f249b00393983822 only tested for the
pg_controldata output for primary servers, but standby servers have
different "Database cluster state" output, so check for that too.
Diagnosed-by: Michael Paquier
Discussion: https://postgr.es/m/20180810164240.GM13638@paquier.xyz
Tom Lane [Mon, 13 Aug 2018 17:07:52 +0000 (13:07 -0400)]
Fix libpq's implementation of per-host connection timeouts.
Commit 5f374fe7a attempted to turn the connect_timeout from an overall
maximum time limit into a per-host limit, but it didn't do a great job of
that. The timer would only get restarted if we actually detected timeout
within connectDBComplete(), not if we changed our attention to a new host
for some other reason. In that case the old timeout continued to run,
possibly causing a premature timeout failure for the new host.
Fix that, and also tweak the logic so that if we do get a timeout,
we advance to the next available IP address, not to the next host name.
There doesn't seem to be a good reason to assume that all the IP
addresses supplied for a given host name will necessarily fail the
same way as the current one. Moreover, this conforms better to the
admittedly-vague documentation statement that the timeout is "per
connection attempt". I changed that to "per host name or IP address"
to be clearer. (Note that reconnections to the same server, such as for
switching protocol version or SSL status, don't get their own separate
timeout; that was true before and remains so.)
Also clarify documentation about the interpretation of connect_timeout
values less than 2.
This seems like a bug, so back-patch to v10 where this logic came in.
Michael Paquier [Mon, 13 Aug 2018 09:49:04 +0000 (11:49 +0200)]
Make autovacuum more aggressive to remove orphaned temp tables
Commit dafa084, added in 10, made the removal of temporary orphaned
tables more aggressive. This commit makes an extra step into the
aggressiveness by adding a flag in each backend's MyProc which tracks
down any temporary namespace currently in use. The flag is set when the
namespace gets created and can be reset if the temporary namespace has
been created in a transaction or sub-transaction which is aborted. The
flag value assignment is assumed to be atomic, so this can be done in a
lock-less fashion like other flags already present in PGPROC like
databaseId or backendId, still the fact that the temporary namespace and
table created are still locked until the transaction creating those
commits acts as a barrier for other backends.
This new flag gets used by autovacuum to discard more aggressively
orphaned tables by additionally checking for the database a backend is
connected to as well as its temporary namespace in-use, removing
orphaned temporary relations even if a backend reuses the same slot as
one which created temporary relations in a past session.
The base idea of this patch comes from Robert Haas, has been written in
its first version by Tsunakawa Takayuki, then heavily reviewed by me.
Author: Tsunakawa Takayuki Reviewed-by: Michael Paquier, Kyotaro Horiguchi, Andres Freund
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8A4DC6@G01JPEXMBYT05
Backpatch: 11-, as PGPROC gains a new flag and we don't want silent ABI
breakages on already released versions.
Amit Kapila [Mon, 13 Aug 2018 04:34:39 +0000 (10:04 +0530)]
Adjust comment atop ExecShutdownNode.
After commits a315b967cc and b805b63ac2, part of the comment atop
ExecShutdownNode is redundant. Adjust it.
Author: Amit Kapila
Backpatch-through: 10 where both the mentioned commits are present.
Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
Amit Kapila [Mon, 13 Aug 2018 02:52:18 +0000 (08:22 +0530)]
Prohibit shutting down resources if there is a possibility of back up.
Currently, we release the asynchronous resources as soon as it is evident
that no more rows will be needed e.g. when a Limit is filled. This can be
problematic especially for custom and foreign scans where we can scan
backward. Fix that by disallowing the shutting down of resources in such
cases.
Reported-by: Robert Haas Analysed-by: Robert Haas and Amit Kapila
Author: Amit Kapila Reviewed-by: Robert Haas
Backpatch-through: 9.6 where this code was introduced
Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
Andrew Gierth [Mon, 13 Aug 2018 00:45:35 +0000 (01:45 +0100)]
Avoid query-lifetime memory leaks in XMLTABLE (bug #15321)
Multiple calls to XMLTABLE in a query (e.g. laterally applying it to a
table with an xml column, an important use-case) were leaking large
amounts of memory into the per-query context, blowing up memory usage.
Repair by reorganizing memory context usage in nodeTableFuncscan; use
the usual per-tuple context for row-by-row evaluations instead of
perValueCxt, and use the explicitly created context -- renamed from
perValueCxt to perTableCxt -- for arguments and state for each
individual table-generation operation.
Backpatch to PG10 where this code was introduced.
Original report by IRC user begriffs; analysis and patch by me.
Reviewed by Tom Lane and Pavel Stehule.
Tom Lane [Sun, 12 Aug 2018 22:46:01 +0000 (18:46 -0400)]
Revert "Distinguish printf-like functions that support %m from those that don't."
This reverts commit 3a60c8ff892a8242b907f44702bfd9f1ff877d45. Buildfarm
results show that that caused a whole bunch of new warnings on platforms
where gcc believes the local printf to be non-POSIX-compliant. This
problem outweighs the hypothetical-anyway possibility of getting warnings
for misuse of %m. We could use gnu_printf archetype when we've substituted
src/port/snprintf.c, but that brings us right back to the problem of not
getting warnings for %m.
A possible answer is to attack it in the other direction by insisting
that %m support be included in printf's feature set, but that will take
more investigation. In the meantime, revert the previous change, and
update the comment for PGAC_C_PRINTF_ARCHETYPE to more fully explain
what's going on.
Tom Lane [Sun, 12 Aug 2018 22:05:49 +0000 (18:05 -0400)]
Fix bogus loop logic in 013_crash_restart test's pump_until subroutine.
The pump_nb() step might've already received the desired data, so we must
check for that at the top of the loop not the bottom. Otherwise, the
call to pump() will sit with nothing to do until the timeout elapses.
pump_until then falls out with apparent success ... but the timeout has
been used up, causing the next call of pump_until to report a timeout
failure. I believe this explains the intermittent timeout failures
we've seen in the buildfarm ever since this test went in. I was able
to reproduce the problem on gaur semi-repeatably, and this appears to
fix it.
In passing, remove a duplicate assignment, fix one stdin-assignment to
look like the rest, and document the test's dependency on test_decoding.
Tom Lane [Sat, 11 Aug 2018 19:53:20 +0000 (15:53 -0400)]
Fix wrong order of operations in inheritance_planner.
When considering a partitioning parent rel, we should stop processing that
subroot as soon as we've done adjust_appendrel_attrs and any securityQuals
updates. The rest of this is unnecessary, and indeed adding duplicate
subquery RTEs to the subroot is *wrong*. As the code stood, the children
of that partition ended up with two sets of copied subquery RTEs, confusing
matters greatly. Even more hilarity ensued if all of the children got
excluded by constraint exclusion, so that the extra RTEs didn't make it
back into the parent rtable.
Per fuzz testing by Andreas Seltenreich. Back-patch to v11 where this
got broken (by commit 0a480502b, it looks like).
Tom Lane [Sat, 11 Aug 2018 15:23:41 +0000 (11:23 -0400)]
Produce compiler errors if errno is referenced inside elog/ereport calls.
It's often unsafe to reference errno within an elog/ereport call, because
there are a lot of sub-functions involved and they might not all preserve
errno. (This is why we support the %m format spec: it works off a value
of errno captured before we execute any potentially-unsafe functions in
the arguments.) Therefore, we have a project policy not to use errno
there.
This patch adds a hack to cause an (admittedly obscure) compiler error
for such unsafe usages. With the current code, the error will only be seen
on Linux, macOS, and FreeBSD, but that should certainly be enough to catch
mistakes in the buildfarm if they somehow get missed earlier.
In addition, fix some places in src/common/exec.c that trip the error.
I think these places are actually all safe, but it's simple enough to
avoid the error by capturing errno manually, and doing so is good
future-proofing in case these call sites get any more complicated.
Tom Lane [Sat, 11 Aug 2018 15:11:05 +0000 (11:11 -0400)]
Distinguish printf-like functions that support %m from those that don't.
The elog/ereport family of functions certainly support the %m format spec,
because they implement it "by hand". But elsewhere we have printf wrappers
that might or might not allow it depending on whether the platform's printf
does. (Most non-glibc versions don't, and notably, src/port/snprintf.c
doesn't.) Hence, rather than using the gnu_printf format archetype
interchangeably for all these functions, use it only for elog/ereport.
This will allow us to get compiler warnings for mistakes like the ones
fixed in commit a13b47a59, at least on platforms where printf doesn't
take %m and gcc is correctly configured to know it. (Unfortunately,
that won't happen on Linux, nor on macOS according to my testing.
It remains to be seen what the buildfarm's gcc-on-Windows animals will
think of this, but we may well have to rely on less-popular platforms
to warn us about unportable code of this kind.)
Peter Geoghegan [Fri, 10 Aug 2018 20:01:34 +0000 (13:01 -0700)]
Handle parallel index builds on mapped relations.
Commit 9da0cc35284, which introduced parallel CREATE INDEX, failed to
propagate relmapper.c backend local cache state to parallel worker
processes. This could result in parallel index builds against mapped
catalog relations where the leader process (participating as a worker)
scans the new, pristine relfilenode, while worker processes scan the
obsolescent relfilenode. When this happened, the final index structure
was typically not consistent with the owning table's structure. The
final index structure could contain entries formed from both heap
relfilenodes. Only rebuilds on mapped catalog relations that occur as
part of a VACUUM FULL or CLUSTER could become corrupt in practice, since
their mapped relation relfilenode swap is what allows the inconsistency
to arise.
On master, fix the problem by propagating the required relmapper.c
backend state as part of standard parallel initialization (Cf. commit 29d58fd3). On v11, simply disallow builds against mapped catalog
relations by deeming them parallel unsafe.
Author: Peter Geoghegan Reported-By: "death lock" Reviewed-By: Tom Lane, Amit Kapila
Bug: #15309
Discussion: https://postgr.es/m/153329671686.1405.18298309097348420351@wrigleys.postgresql.org
Backpatch: 11-, where parallel CREATE INDEX was introduced.
Michael Paquier [Fri, 10 Aug 2018 16:26:59 +0000 (18:26 +0200)]
Improve TRUNCATE by avoiding early lock queue
A caller of TRUNCATE could previously queue for an access exclusive lock
on a relation it may not have permission to truncate, potentially
interfering with users authorized to work on it. This can be very
intrusive depending on the lock attempted to be taken. For example,
pg_authid could be blocked, preventing any authentication attempt to
happen on a PostgreSQL instance.
This commit fixes the case of TRUNCATE so as RangeVarGetRelidExtended is
used with a callback doing the necessary ACL checks at an earlier stage,
avoiding lock queuing issues, so as an immediate failure happens for
unprivileged users instead of waiting on a lock that would not be
taken.
This is rather similar to the type of work done in cbe24a6 for CLUSTER,
and the code of TRUNCATE is this time refactored so as there is no
user-facing changes. As the commit for CLUSTER, no back-patch is done.
Reported-by: Lloyd Albin, Jeremy Schneider
Author: Michael Paquier
Reviewed by: Nathan Bossart, Kyotaro Horiguchi
Discussion: https://postgr.es/m/152512087100.19803.12733865831237526317@wrigleys.postgresql.org
Discussion: https://postgr.es/m/20180806165816.GA19883@paquier.xyz
Add missing documentation for argument of amcostestimate()
5262f7a4fc44 have introduced parallel index scan. In order to estimate the
number of parallel workers, it adds extra argument to amcostestimate() index
access method API function. However, this extra argument was missed in the
documentation. This commit fixes that.
Discussion: https://postgr.es/m/4128fdb4-8b63-2e05-38f6-3125f8c27263%40lab.ntt.co.jp
Author: Tatsuro Yamada, Alexander Korotkov
Backpatch-through: 10
Tom Lane [Thu, 9 Aug 2018 19:21:09 +0000 (15:21 -0400)]
Document need to clear MAKELEVEL when invoking PG build from a makefile.
Since commit 3b8f6e75f, failure to do this would lead to
submake-generated-headers not doing anything, so that references to
generated or symlinked headers would fail. Previous to that, the
omission only led to temp-install not doing anything, which apparently
affects many fewer people (doesn't anybody use "make check" in their
build rules??). Hence, backpatch to v11 but not further.
Per complaints from Christoph Berg, Jakob Egger, and others.
Bruce Momjian [Thu, 9 Aug 2018 14:13:15 +0000 (10:13 -0400)]
docs: Only first instance of a PREPARE parameter sets data type
If the first reference to $1 is "($1 = col) or ($1 is null)", the data
type can be determined, but not for "($1 is null) or ($1 = col)". This
change documents this.
Michael Paquier [Thu, 9 Aug 2018 07:40:15 +0000 (09:40 +0200)]
Restrict access to reindex of shared catalogs for non-privileged users
A database owner running a database-level REINDEX has the possibility to
also do the operation on shared system catalogs without being an owner
of them, which allows him to block resources it should not have access
to. The same goes for a schema owner. For example, PostgreSQL would go
unresponsive and even block authentication if a lock is waited for
pg_authid. This commit makes sure that a user running a REINDEX SYSTEM,
DATABASE or SCHEMA only works on the following relations:
- The user is a superuser
- The user is the table owner
- The user is the database/schema owner, only if the relation worked on
is not shared.
Robert has worded most the documentation changes, and I have coded the
core part.
Reported-by: Lloyd Albin, Jeremy Schneider
Author: Michael Paquier, Robert Haas
Reviewed by: Nathan Bossart, Kyotaro Horiguchi
Discussion: https://postgr.es/m/152512087100.19803.12733865831237526317@wrigleys.postgresql.org
Discussion: https://postgr.es/m/20180805211059.GA2185@paquier.xyz
Backpatch-through: 11- as the current behavior has been around for a
very long time and could be disruptive for already released branches.
Tom Lane [Thu, 9 Aug 2018 00:02:10 +0000 (20:02 -0400)]
Remove bogus Assert in make_partitionedrel_pruneinfo().
This Assert thought that a given rel couldn't be both leaf and
non-leaf, but it turns out that in some unusual plan trees
that's wrong, so remove it.
The lack of testing for cases like that is quite concerning ---
there is little reason for confidence that there aren't other
bugs in the area. But developing a stable test case seems
rather difficult, and in any case we don't need this Assert.
Peter Geoghegan [Wed, 8 Aug 2018 19:56:11 +0000 (12:56 -0700)]
Doc: Correct description of amcheck example query.
The amcheck documentation incorrectly claimed that its example query
verifies every catalog index in the database. In fact, the query only
verifies the 10 largest indexes (as determined by pg_class.relpages).
Adjust the description accordingly.
Backpatch: 10-, where contrib/amcheck was introduced.
Tom Lane [Wed, 8 Aug 2018 18:32:29 +0000 (14:32 -0400)]
Remove unwanted "garbage cleanup" logic in Makefiles.
GNUmakefile.in defined a macro "garbage" that seems to have been meant
as a suitable target for automatic "rm -rf" treatment, but it isn't
actually used anywhere (and indeed never was, AFAICT).
Moreover, we have concluded that the Makefiles shouldn't take it upon
themselves to remove files that aren't expected by-products of building,
so that doing anything like that would be against project policy anyway.
Hence, just remove the macro.
Grepping around finds another violation of that policy in ecpg/preproc,
so clean that up too.
Don't run atexit callbacks in quickdie signal handlers.
exit() is not async-signal safe. Even if the libc implementation is, 3rd
party libraries might have installed unsafe atexit() callbacks. After
receiving SIGQUIT, we really just want to exit as quickly as possible, so
we don't really want to run the atexit() callbacks anyway.
The original report by Jimmy Yih was a self-deadlock in startup_die().
However, this patch doesn't address that scenario; the signal handling
while waiting for the startup packet is more complicated. But at least this
alleviates similar problems in the SIGQUIT handlers, like that reported
by Asim R P later in the same thread.
Tom Lane [Wed, 8 Aug 2018 15:44:50 +0000 (11:44 -0400)]
Match RelOptInfos by relids not pointer equality.
Commit 1c2cb2744 added some code that tried to detect whether two
RelOptInfos were the "same" rel by pointer comparison; but it turns
out that inheritance_planner breaks that, through its shenanigans
with copying some relations forward into new subproblems. Compare
relid sets instead. Add a regression test case to exercise this
area.
Problem reported by Rushabh Lathia; diagnosis and fix by Amit Langote,
modified a bit by me.
Tom Lane [Tue, 7 Aug 2018 20:32:50 +0000 (16:32 -0400)]
Don't record FDW user mappings as members of extensions.
CreateUserMapping has a recordDependencyOnCurrentExtension call that's
been there since extensions were introduced (very possibly my fault).
However, there's no support anywhere else for user mappings as members
of extensions, nor are they listed as a possible member object type in
the documentation. Nor does it really seem like a good idea for user
mappings to belong to extensions when roles don't. Hence, remove the
bogus call.
(As we saw in bug #15310, the lack of any pg_dump support for this case
ensures that any such membership record would silently disappear during
pg_upgrade. So there's probably no need for us to do anything else
about cleaning up after this mistake.)
Tom Lane [Tue, 7 Aug 2018 20:00:44 +0000 (16:00 -0400)]
Fix incorrect initialization of BackendActivityBuffer.
Since commit c8e8b5a6e, this has been zeroed out using the wrong length.
In practice the length would always be too small, leading to not zeroing
the whole buffer rather than clobbering additional memory; and that's
pretty harmless, both because shmem would likely start out as zeroes
and because we'd reinitialize any given entry before use. Still,
it's bogus, so fix it.
Tom Lane [Tue, 7 Aug 2018 19:43:48 +0000 (15:43 -0400)]
Fix pg_upgrade to handle event triggers in extensions correctly.
pg_dump with --binary-upgrade must emit ALTER EXTENSION ADD commands
for all objects that are members of extensions. It forgot to do so for
event triggers, as per bug #15310 from Nick Barnes. Back-patch to 9.3
where event triggers were introduced.
Tom Lane [Tue, 7 Aug 2018 17:13:42 +0000 (13:13 -0400)]
Ensure pg_dump_sort.c sorts null vs non-null namespace consistently.
The original coding here (which is, I believe, my fault) supposed that
it didn't need to concern itself with the possibility that one object
of a given type-priority has a namespace while another doesn't. But
that's not reliably true anymore, if it ever was; and if it does happen
then it's possible that DOTypeNameCompare returns self-inconsistent
comparison results. That leads to unspecified behavior in qsort()
and a resultant weird output order from pg_dump.
This should end up being only a cosmetic problem, because any ordering
constraints that actually matter should be enforced by the later
dependency-based sort. Still, it's a bug, so back-patch.
Report and fix by Jacob Champion, though I editorialized on his
patch to the extent of making NULL sort after non-NULL, for consistency
with our usual sorting definitions.
Tom Lane [Mon, 6 Aug 2018 14:53:35 +0000 (10:53 -0400)]
Fix failure to reset libpq's state fully between connection attempts.
The logic in PQconnectPoll() did not take care to ensure that all of
a PGconn's internal state variables were reset before trying a new
connection attempt. If we got far enough in the connection sequence
to have changed any of these variables, and then decided to try a new
server address or server name, the new connection might be completed
with some state that really only applied to the failed connection.
While this has assorted bad consequences, the only one that is clearly
a security issue is that password_needed didn't get reset, so that
if the first server asked for a password and the second didn't,
PQconnectionUsedPassword() would return an incorrect result. This
could be leveraged by unprivileged users of dblink or postgres_fdw
to allow them to use server-side login credentials that they should
not be able to use.
Other notable problems include the possibility of forcing a v2-protocol
connection to a server capable of supporting v3, or overriding
"sslmode=prefer" to cause a non-encrypted connection to a server that
would have accepted an encrypted one. Those are certainly bugs but
it's harder to paint them as security problems in themselves. However,
forcing a v2-protocol connection could result in libpq having a wrong
idea of the server's standard_conforming_strings setting, which opens
the door to SQL-injection attacks. The extent to which that's actually
a problem, given the prerequisite that the attacker needs control of
the client's connection parameters, is unclear.
These problems have existed for a long time, but became more easily
exploitable in v10, both because it introduced easy ways to force libpq
to abandon a connection attempt at a late stage and then try another one
(rather than just giving up), and because it provided an easy way to
specify multiple target hosts.
Fix by rearranging PQconnectPoll's state machine to provide centralized
places to reset state properly when moving to a new target host or when
dropping and retrying a connection to the same host.
Tom Lane, reviewed by Noah Misch. Our thanks to Andrew Krasichkov
for finding and reporting the problem.
There are some problems with the tls-unique channel binding type. It's not
supported by all SSL libraries, and strictly speaking it's not defined for
TLS 1.3 at all, even though at least in OpenSSL, the functions used for it
still seem to work with TLS 1.3 connections. And since we had no
mechanism to negotiate what channel binding type to use, there would be
awkward interoperability issues if a server only supported some channel
binding types. tls-server-end-point seems feasible to support with any SSL
library, so let's just stick to that.
This removes the scram_channel_binding libpq option altogether, since there
is now only one supported channel binding type.
This also removes all the channel binding tests from the SSL test suite.
They were really just testing the scram_channel_binding option, which
is now gone. Channel binding is used if both client and server support it,
so it is used in the existing tests. It would be good to have some tests
specifically for channel binding, to make sure it really is used, and the
different combinations of a client and a server that support or doesn't
support it. The current set of settings we have make it hard to write such
tests, but I did test those things manually, by disabling
HAVE_BE_TLS_GET_CERTIFICATE_HASH and/or
HAVE_PGTLS_GET_PEER_CERTIFICATE_HASH.
I also removed the SCRAM_CHANNEL_BINDING_TLS_END_POINT constant. This is a
matter of taste, but IMO it's more readable to just use the
"tls-server-end-point" string.
Refactor the checks on whether the SSL library supports the functions
needed for tls-server-end-point channel binding. Now the server won't
advertise, and the client won't choose, the SCRAM-SHA-256-PLUS variant, if
compiled with an OpenSSL version too old to support it.
In the passing, add some sanity checks to check that the chosen SASL
mechanism, SCRAM-SHA-256 or SCRAM-SHA-256-PLUS, matches whether the SCRAM
exchange used channel binding or not. For example, if the client selects
the non-channel-binding variant SCRAM-SHA-256, but in the SCRAM message
uses channel binding anyway. It's harmless from a security point of view,
I believe, and I'm not sure if there are some other conditions that would
cause the connection to fail, but it seems better to be strict about these
things and check explicitly.
Tom Lane [Sun, 5 Aug 2018 03:49:53 +0000 (23:49 -0400)]
Update version 11 release notes.
Remove description of commit 1944cdc98, which has now been back-patched
so it's not relevant to v11 any longer. Add descriptions of other
recent commits that seemed worth mentioning.
I marked the update as stopping at 2018-07-30, because it's unclear
whether d06eebce5 will be allowed to stay in v11, and I didn't feel like
putting effort into writing a description of it yet. If it does stay,
I think it will deserve mention in the Source Code section.
Tom Lane [Sat, 4 Aug 2018 23:38:58 +0000 (19:38 -0400)]
Fix INSERT ON CONFLICT UPDATE through a view that isn't just SELECT *.
When expanding an updatable view that is an INSERT's target, the rewriter
failed to rewrite Vars in the ON CONFLICT UPDATE clause. This accidentally
worked if the view was just "SELECT * FROM ...", as the transformation
would be a no-op in that case. With more complicated view targetlists,
this omission would often lead to "attribute ... has the wrong type" errors
or even crashes, as reported by Mario De Frutos Dieguez.
Fix by adding code to rewriteTargetView to fix up the data structure
correctly. The easiest way to update the exclRelTlist list is to rebuild
it from scratch looking at the new target relation, so factor the code
for that out of transformOnConflictClause to make it sharable.
In passing, avoid duplicate permissions checks against the EXCLUDED
pseudo-relation, and prevent useless view expansion of that relation's
dummy RTE. The latter is only known to happen (after this patch) in cases
where the query would fail later due to not having any INSTEAD OF triggers
for the view. But by exactly that token, it would create an unintended
and very poorly tested state of the query data structure, so it seems like
a good idea to prevent it from happening at all.
This has been broken since ON CONFLICT was introduced, so back-patch
to 9.5.
Dean Rasheed, based on an earlier patch by Amit Langote;
comment-kibitzing and back-patching by me
Michael Paquier [Sat, 4 Aug 2018 20:31:18 +0000 (05:31 +0900)]
Reset properly errno before calling write()
6cb3372 enforces errno to ENOSPC when less bytes than what is expected
have been written when it is unset, though it forgot to properly reset
errno before doing a system call to write(), causing errno to
potentially come from a previous system call.
Reported-by: Tom Lane
Author: Michael Paquier Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/31797.1533326676@sss.pgh.pa.us
Noah Misch [Sat, 4 Aug 2018 03:53:25 +0000 (20:53 -0700)]
Make "kerberos" test suite independent of "localhost" name resolution.
This suite malfunctioned if the canonical name of "localhost" was
something other than "localhost", such as "localhost.localdomain". Use
hostaddr=127.0.0.1 and a fictitious host=, so the resolver's answers for
"localhost" don't affect the outcome. Back-patch to v11, which
introduced this test suite.
Peter Geoghegan [Fri, 3 Aug 2018 21:45:11 +0000 (14:45 -0700)]
Add table relcache invalidation to index builds.
It's necessary to make sure that owning tables have a relcache
invalidation prior to advancing the command counter to make
newly-entered catalog tuples for the index visible. inval.c must be
able to maintain the consistency of the local caches in the event of
transaction abort. There is usually only a problem when CREATE INDEX
transactions abort, since there is a generic invalidation once we reach
index_update_stats().
This bug is of long standing. Problems were made much more likely by
the addition of parallel CREATE INDEX (commit 9da0cc35284), but it is
strongly suspected that similar problems can be triggered without
involving plan_create_index_workers(). (plan_create_index_workers()
triggers a relcache build or rebuild, which previously only happened in
rare edge cases.)
Author: Peter Geoghegan Reported-By: Luca Ferrari Diagnosed-By: Andres Freund Reviewed-By: Andres Freund
Discussion: https://postgr.es/m/CAKoxK+5fVodiCtMsXKV_1YAKXbzwSfp7DgDqUmcUAzeAhf=HEQ@mail.gmail.com
Backpatch: 9.3-
Tom Lane [Fri, 3 Aug 2018 16:20:47 +0000 (12:20 -0400)]
Remove no-longer-appropriate special case in psql's \conninfo code.
\conninfo prints the results of PQhost() and some other libpq functions.
It used to override the PQhost() result with the hostaddr parameter if
that'd been given, but that's unhelpful when multiple hosts were listed
in the connection string. Furthermore, it seems unnecessary in the wake
of commit 1944cdc98, since PQhost does any useful substitution itself.
So let's just remove the extra code and print PQhost()'s result without
any editorialization.
Tom Lane [Fri, 3 Aug 2018 16:12:10 +0000 (12:12 -0400)]
Change libpq's internal uses of PQhost() to inspect host field directly.
Commit 1944cdc98 changed PQhost() to return the hostaddr value when that
is specified and host isn't. This is a good idea in general, but
fe-auth.c and related files contain PQhost() calls for which it isn't.
Specifically, when we compare SSL certificates or other server identity
information to the host field, we do not want to use hostaddr instead;
that's not what's documented, that's not what happened pre-v10, and
it doesn't seem like a good idea.
Instead, we can just look at connhost[].host directly. This does what
we want in v10 and up; in particular, if neither host nor hostaddr
were given, the host field will be replaced with the default host name.
That seems useful, and it's likely the reason that these places were
coded to call PQhost() originally (since pre-v10, the stored field was
not replaced with the default).
Amit Kapila [Fri, 3 Aug 2018 05:32:02 +0000 (11:02 +0530)]
Fix buffer usage stats for parallel nodes.
The buffer usage stats is accounted only for the execution phase of the
node. For Gather and Gather Merge nodes, such stats are accumulated at
the time of shutdown of workers which is done after execution of node due
to which we missed to account them for such nodes. Fix it by treating
nodes as running while we shut down them.
We can also miss accounting for a Limit node when Gather or Gather Merge
is beneath it, because it can finish the execution before shutting down
such nodes. So we allow a Limit node to shut down the resources before it
completes the execution.
In the passing fix the gather node code to allow workers to shut down as
soon as we find that all the tuples from the workers have been retrieved.
The original code use to do that, but is accidently removed by commit 01edb5c7fc.
Reported-by: Adrien Nayrat
Author: Amit Kapila and Robert Haas Reviewed-by: Robert Haas and Andres Freund
Backpatch-through: 9.6 where this code was introduced
Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
Amit Kapila [Fri, 3 Aug 2018 03:41:37 +0000 (09:11 +0530)]
Match the buffer usage tracking for leader and worker backends.
In the leader backend, we don't track the buffer usage for ExecutorStart
phase whereas in worker backend we track it for ExecutorStart phase as
well. This leads to different value for buffer usage stats for the
parallel and non-parallel query. Change the code so that worker backend
also starts tracking buffer usage after ExecutorStart.
Author: Amit Kapila and Robert Haas Reviewed-by: Robert Haas and Andres Freund
Backpatch-through: 9.6 where this code was introduced
Discussion: https://postgr.es/m/86137f17-1dfb-42f9-7421-82fd786b04a1@anayrat.info
Thomas Munro [Wed, 1 Aug 2018 23:25:31 +0000 (11:25 +1200)]
Add missing header include to pmsignal.h.
pmsignal.h uses sig_atomic_t in some builds, but relied on signal.h
having been included already. We could include it conditionally
but evidently that wouldn't save anything in practice and would
add more ugly macros, so let's just include signal.h always.
Reported-by: Tom Lane
Discussion: https://postgr.es/m/4166.1533154074%40sss.pgh.pa.us
Tom Lane [Wed, 1 Aug 2018 23:42:46 +0000 (19:42 -0400)]
Fix run-time partition pruning for appends with multiple source rels.
The previous coding here supposed that if run-time partitioning applied to
a particular Append/MergeAppend plan, then all child plans of that node
must be members of a single partitioning hierarchy. This is totally wrong,
since an Append could be formed from a UNION ALL: we could have multiple
hierarchies sharing the same Append, or child plans that aren't part of any
hierarchy.
To fix, restructure the related plan-time and execution-time data
structures so that we can have a separate list or array for each
partitioning hierarchy. Also track subplans that are not part of any
hierarchy, and make sure they don't get pruned.
Per reports from Phil Florent and others. Back-patch to v11, since
the bug originated there.
David Rowley, with a lot of cosmetic adjustments by me; thanks also
to Amit Langote for review.
Alvaro Herrera [Wed, 1 Aug 2018 21:39:07 +0000 (17:39 -0400)]
Fix logical replication slot initialization
This was broken in commit 9c7d06d60680, which inadvertently gave the
wrong value to fast_forward in one StartupDecodingContext call. Fix by
flipping the value. Add a test for the obvious error, namely trying to
initialize a replication slot with an nonexistent output plugin.
While at it, move the CreateDecodingContext call earlier, so that any
errors are reported before sending the CopyBoth message.
Author: Dave Cramer <davecramer@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CADK3HHLVkeRe1v4P02-5hj55H3_yJg3AEtpXyEY5T3wuzO2jSg@mail.gmail.com
Alvaro Herrera [Wed, 1 Aug 2018 19:06:47 +0000 (15:06 -0400)]
Fix per-tuple memory leak in partition tuple routing
Some operations were being done in a longer-lived memory context,
causing intra-query leaks. It's not noticeable unless you're doing a
large COPY, but if you are, it eats enough memory to cause a problem.
Tom Lane [Wed, 1 Aug 2018 16:30:36 +0000 (12:30 -0400)]
Fix libpq's code for searching .pgpass; rationalize empty-list-item cases.
Before v10, we always searched ~/.pgpass using the host parameter,
and nothing else, to match to the "hostname" field of ~/.pgpass.
(However, null host or host matching DEFAULT_PGSOCKET_DIR was replaced by
"localhost".) In v10, this got broken by commit 274bb2b38, repaired by
commit bdac9836d, and broken again by commit 7b02ba62e; in the code
actually shipped, we'd search with hostaddr if both that and host were
specified --- though oddly, *not* if only hostaddr were specified.
Since this is directly contrary to the documentation, and not
backwards-compatible, it's clearly a bug.
However, the change wasn't totally without justification, even though it
wasn't done quite right, because the pre-v10 behavior has arguably been
buggy since we added hostaddr. If hostaddr is specified and host isn't,
the pre-v10 code will search ~/.pgpass for "localhost", and ship that
password off to a server that most likely isn't local at all. That's
unhelpful at best, and could be a security breach at worst.
Therefore, rather than just revert to that old behavior, let's define
the behavior as "search with host if provided, else with hostaddr if
provided, else search for localhost". (As before, a host name matching
DEFAULT_PGSOCKET_DIR is replaced by localhost.) This matches the
behavior of the actual connection code, so that we don't pick up an
inappropriate password; and it allows useful searches to happen when
only hostaddr is given.
While we're messing around here, ensure that empty elements within a
host or hostaddr list select the same behavior as a totally-empty
field would; for instance "host=a,,b" is equivalent to "host=a,/tmp,b"
if DEFAULT_PGSOCKET_DIR is /tmp. Things worked that way in some cases
already, but not consistently so, which contributed to the confusion
about what key ~/.pgpass would get searched with.
Update documentation accordingly, and also clarify some nearby text.
Back-patch to v10 where the host/hostaddr list functionality was
introduced.
projects / postgresql / log