Robert Foggia of Trustwave reported that read_tablespace_map()
fails to prevent an overrun of its on-stack input buffer.
Since the tablespace map file is presumed trustworthy, this does
not seem like an interesting security vulnerability, but still
we should fix it just in the name of robustness.
While here, document that pg_basebackup's --tablespace-mapping option
doesn't work with tar-format output, because it doesn't. To make it
work, we'd have to modify the tablespace_map file within the tarball
sent by the server, which might be possible but I'm not volunteering.
(Less-painful solutions would require changing the basebackup protocol
so that the source server could adjust the map. That's not very
appetizing either.)
After reading the root cert list from the ssl_ca_file, immediately
install it as client CA list of the new SSL context. That gives the
SSL context ownership of the list, so that SSL_CTX_free will free it.
This avoids a permanent memory leak if we fail further down in
be_tls_init(), which could happen if bogus CRL data is offered.
The leak could only amount to something if the CRL parameters get
broken after server start (else we'd just quit) and then the server
is SIGHUP'd many times without fixing the CRL data. That's rather
unlikely perhaps, but it seems worth fixing, if only because the
code is clearer this way.
While we're here, add some comments about the memory management
aspects of this logic.
Noted by Jelte Fennema and independently by Andres Freund.
Back-patch to v10; before commit de41869b6 it doesn't matter,
since we'd not re-execute this code during SIGHUP.
Discussion: https://postgr.es/m/16160-18367e56e9a28264@postgresql.org
psql's editing commands decide whether the user has edited the file
by checking for change of modification timestamp. This is probably
fine for a pre-existing file, but with a temporary file that is
created within the command, it's possible for a fast typist to
save-and-exit in less than the one-second granularity of stat(2)
timestamps. On Windows FAT filesystems the granularity is even
worse, 2 seconds, making the race a bit easier to hit.
To fix, try to set the temp file's mod time to be two seconds ago.
It's unlikely this would fail, but then again the race condition
itself is unlikely, so just ignore any error.
Also, we might as well check the file size as well as its mod time.
While this is a difficult bug to hit, it still seems worth
back-patching, to ensure that users' edits aren't lost.
Laurenz Albe, per gripe from Jacob Champion; based on fix suggestions
from Jacob and myself
Discussion: https://postgr.es/m/0ba3f2a658bac6546d9934ab6ba63a805d46a49b.camel@cybertec.at
GENERATED ALWAYS AS IDENTITY implies NOT NULL, but the code failed
to complain if you overrode that with "GENERATED ALWAYS AS IDENTITY
NULL". One might think the old behavior was a feature, but it was
inconsistent because the outcome varied depending on the order of
the clauses, so it seems to have been just an oversight.
Per bug #16913 from Pavel Boev. Back-patch to v10 where identity
columns were introduced.
Vik Fearing (minor tweaks by me)
Discussion: https://postgr.es/m/16913-3b5198410f67d8c6@postgresql.org
Commit 92785dac2 copied some logic related to advancement of inStart
from pqParseInput3 into getRowDescriptions and getAnotherTuple,
because it wanted to allow user-defined row processor callbacks to
potentially longjmp out of the library, and inStart would have to be
updated before that happened to avoid an infinite loop. We later
decided that that API was impossibly fragile and reverted it, but
we didn't undo all of the related code changes, and this bit of
messiness survived. Undo it now so that there's just one place in
pqParseInput3's processing where inStart is advanced; this will
simplify addition of better tracing support.
getParamDescriptions had grown similar processing somewhere along
the way (not in 92785dac2; I didn't track down just when), but it's
actually buggy because its handling of corrupt-message cases seems to
have been copied from the v2 logic where we lacked a known message
length. The cases where we "goto not_enough_data" should not simply
return EOF, because then we won't consume the message, potentially
creating an infinite loop. That situation now represents a
definitively corrupt message, and we should report it as such.
Although no field reports of getParamDescriptions getting stuck in
a loop have been seen, it seems appropriate to back-patch that fix.
I chose to back-patch all of this to keep the logic looking more alike
in supported branches.
Discussion: https://postgr.es/m/2217283.1615411989@sss.pgh.pa.us
"SELECT pg_import_system_collations(0)" caused an assertion failure.
With a random nonzero argument --- or indeed with zero, in non-assert
builds --- it would happily make pg_collation entries with garbage
values of collnamespace. These are harmless as far as I can tell
(unless maybe the OID happens to become used for a schema, later on?).
In any case this isn't a security issue, since the function is
superuser-only. But it seems like a gotcha for unwary DBAs, so let's
add a check that the given OID belongs to some schema.
Back-patch to v10 where this function was introduced.
On Windows, CMD.EXE allegedly does not run a command that uses forward slashes,
so let's convert the path to use backslashes instead.
Backpatch to 10.
Author: Nitin Jadhav <nitinjadhavpostgres@gmail.com>
Reviewed-by: Juan José Santamaría Flecha <juanjo.santamaria@gmail.com>
Discussion: https://postgr.es/m/CAMm1aWaNDuaPYFYMAqDeJrZmPtNvLcJRS++CcZWY8LT6KcoBZw@mail.gmail.com
Break the synopsis into named parts to make it less confusing.
Make more than zero effort at applying SGML markup. Do a bit
of copy-editing of nearby text.
The synopsis revision is by Alvaro Herrera and Paul Förster,
the rest is my fault. Back-patch to v10 where multi-host
connection strings appeared.
Discussion: https://postgr.es/m/6E752D6B-487C-463E-B6E2-C32E7FB007EA@gmail.com
Commit 866e24d47db1 added an assert that HEAP_XMAX_LOCK_ONLY and
HEAP_KEYS_UPDATED cannot appear together, on the faulty assumption that
the latter necessarily referred to an update and not a tuple lock; but
that's wrong, because SELECT FOR UPDATE can use precisely that
combination, as evidenced by the amcheck test case added here.
Remove the Assert(), and also patch amcheck's verify_heapam.c to not
complain if the combination is found. Also, out of overabundance of
caution, update (across all branches) README.tuplock to be more explicit
about this.
Author: Julien Rouhaud <rjuju123@gmail.com>
Reviewed-by: Mahendra Singh Thalor <mahi6run@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Discussion: https://postgr.es/m/20210124061758.GA11756@nol
While poking at the regex code, I happened to notice that the bug
squashed in commit afcc8772e had a sibling: next() failed to return
a specific value associated with the '}' token for a "\{m,n\}"
quantifier when parsing in basic RE mode. Again, this could result
in treating the quantifier as non-greedy, which it never should be in
basic mode. For that to happen, the last character before "\}" that
sets "nextvalue" would have to set it to zero, or it'd have to have
accidentally been zero from the start. The failure can be provoked
repeatably with, for example, a bound ending in digit "0".
Like the previous patch, back-patch all the way.
FreeBSD 13 gained O_DSYNC, which would normally cause wal_sync_method to
choose open_datasync as its default value. That may not be a good
choice for all systems, and performs worse than fdatasync in some
scenarios. Let's preserve the existing default behavior for now.
Like commit 576477e73c4, which did the same for Linux, back-patch to all
supported releases.
Discussion: https://postgr.es/m/CA%2BhUKGLsAMXBQrCxCXoW-JsUYmdOL8ALYvaX%3DCrHqWxm-nWbGA%40mail.gmail.com
While cleaning up after a parallel query or parallel index creation that
created temporary files, we could be interrupted by a statement timeout.
The error handling path would then fail to clean up the files when it
ran dsm_detach() again, because the callback was already popped off the
list. Prevent this hazard by holding interrupts while the cleanup code
runs.
Thanks to Heikki Linnakangas for this suggestion, and also to Kyotaro
Horiguchi, Masahiko Sawada, Justin Pryzby and Tom Lane for discussion of
this and earlier ideas on how to fix the problem.
Back-patch to all supported releases.
Reported-by: Justin Pryzby <pryzby@telsasoft.com>
Discussion: https://postgr.es/m/20191212180506.GR2082@telsasoft.com
Modern gcc and clang compilers offer alignment sanitizers, which help to detect
pointer misalignment. However, our codebase already contains x86-specific
crc32 computation code, which uses unalignment access. Thankfully, those
compilers also support the attribute, which disables alignment sanitizers at
the function level. This commit adds pg_attribute_no_sanitize_alignment(),
which wraps this attribute, and applies it to pg_comp_crc32c_sse42() function.
Back-patch of commits 993bdb9f9 and ad2ad698a, to enable doing
alignment testing in all supported branches.
Discussion: https://postgr.es/m/CAPpHfdsne3%3DT%3DfMNU45PtxdhSL_J2PjLTeS8rwKnJzUR4YNd4w%40mail.gmail.com
Discussion: https://postgr.es/m/475514.1612745257%40sss.pgh.pa.us
Author: Alexander Korotkov, revised by Tom Lane
Reviewed-by: Tom Lane
Given a regex pattern with a very long fixed prefix (approaching 500
characters), the result of pow(FIXED_CHAR_SEL, fixed_prefix_len) can
underflow to zero. Typically the preceding selectivity calculation
would have underflowed as well, so that we compute 0/0 and get NaN.
In released branches this leads to an assertion failure later on.
That doesn't happen in HEAD, for reasons I've not explored yet,
but it's surely still a bug.
To fix, just skip the division when the pow() result is zero, so
that we'll (most likely) return a zero selectivity estimate. In
the edge cases where "sel" didn't yet underflow, perhaps this
isn't desirable, but I'm not sure that the case is worth spending
a lot of effort on. The results of regex_selectivity_sub() are
barely worth the electrons they're written on anyway :-(
Per report from Alexander Lakhin. Back-patch to all supported versions.
Discussion: https://postgr.es/m/6de0a0c3-ada9-cd0c-3e4e-2fa9964b41e3@gmail.com
This reverts commit ed290896335414c6c069b9ccae1f3dcdd2fac6ba and
equivalent back-branch commits. The issue is subtler than I thought,
and it's far from new, so just before a release deadline is no time
to be fooling with it. We'll consider what to do at a bit more
leisure.
Discussion: https://postgr.es/m/CAJcOf-fAdj=nDKMsRhQzndm-O13NY4dL6xGcEvdX5Xvbbi0V7g@mail.gmail.com
rewriteRuleAction() neglected this step, although it was careful to
propagate other similar flags such as hasSubLinks or hasRowSecurity.
Omitting to transfer hasRecursive is just cosmetic at the moment,
but omitting hasModifyingCTE is a live bug, since the executor
certainly looks at that.
The proposed test case only fails back to v10, but since the executor
examines hasModifyingCTE in 9.x as well, I suspect that a test case
could be devised that fails in older branches. Given the nearness
of the release deadline, though, I'm not going to spend time looking
for a better test.
Report and patch by Greg Nancarrow, cosmetic changes by me
Discussion: https://postgr.es/m/CAJcOf-fAdj=nDKMsRhQzndm-O13NY4dL6xGcEvdX5Xvbbi0V7g@mail.gmail.com
Generally, members of inheritance trees must be plain tables (or,
in more recent versions, foreign tables). ALTER TABLE INHERIT
rejects creating an inheritance relationship that has a view at
either end. When DefineQueryRewrite attempts to convert a relation
to a view, it already had checks prohibiting doing so for partitioning
parents or children as well as traditional-inheritance parents ...
but it neglected to check that a traditional-inheritance child wasn't
being converted. Since the planner assumes that any inheritance
child is a table, this led to making plans that tried to do a physical
scan on a view, causing failures (or even crashes, in recent versions).
One could imagine trying to support such a case by expanding the view
normally, but since the rewriter runs before the planner does
inheritance expansion, it would take some very fundamental refactoring
to make that possible. There are probably a lot of other parts of the
system that don't cope well with such a situation, too. For now,
just forbid it.
Per bug #16856 from Yang Lin. Back-patch to all supported branches.
(In versions before v10, this includes back-patching the portion of
commit 501ed02cf that added has_superclass(). Perhaps the lack of
that infrastructure partially explains the missing check.)
Discussion: https://postgr.es/m/16856-0363e05c6e1612fd@postgresql.org
If a multi-byte character is escaped with a backslash in TEXT mode input,
and the encoding is one of the client-only encodings where the bytes after
the first one can have an ASCII byte "embedded" in the char, we didn't
skip the character correctly. After a backslash, we only skipped the first
byte of the next character, so if it was a multi-byte character, we would
try to process its second byte as if it was a separate character. If it
was one of the characters with special meaning, like '\n', '\r', or
another '\\', that would cause trouble.
One such exmple is the byte sequence '\x5ca45c2e666f6f' in Big5 encoding.
That's supposed to be [backslash][two-byte character][.][f][o][o], but
because the second byte of the two-byte character is 0x5c, we incorrectly
treat it as another backslash. And because the next character is a dot, we
parse it as end-of-copy marker, and throw an "end-of-copy marker corrupt"
error.
Backpatch to all supported versions.
Reviewed-by: John Naylor, Kyotaro Horiguchi
Discussion: https://www.postgresql.org/message-id/a897f84f-8dca-8798-3139-07da5bb38728%40iki.fi
The ExecutorEnd hook is invoked in a context that could be quite
long-lived, not the executor's own per-query context as I think
we were sort of assuming. Thus, any cruft generated while producing
the EXPLAIN output could accumulate over multiple queries. This can
result in spectacular leakage if log_nested_statements is on, and
even without that I'm surprised nobody complained before.
To fix, just switch into the executor's context so that anything we
allocate will be released when standard_ExecutorEnd frees the executor
state. We might as well nuke the code's retail pfree of the explain
output string, too; that's laughably inadequate to the need.
Japin Li, per report from Jeff Janes. This bug is old, so
back-patch to all supported branches.
Discussion: https://postgr.es/m/CAMkU=1wCVtbeRn0s9gt12KwQ7PLXovbpM8eg25SYocKW3BT4hg@mail.gmail.com
In a cluster having used CREATE INDEX CONCURRENTLY while having enabled
prepared transactions, queries that use the resulting index can silently
fail to find rows. Fix this for future CREATE INDEX CONCURRENTLY by
making it wait for prepared transactions like it waits for ordinary
transactions. This expands the VirtualTransactionId structure domain to
admit prepared transactions. It may be necessary to reindex to recover
from past occurrences. Back-patch to 9.5 (all supported versions).
Andrey Borodin, reviewed (in earlier versions) by Tom Lane and Michael
Paquier.
Discussion: https://postgr.es/m/2E712143-97F7-4890-B470-4A35142ABC82@yandex-team.ru
Per buildfarm and local experimentation, bleeding-edge gcc isn't
convinced that the MemSet in reorder_function_arguments() is safe.
Shut it up by adding an explicit check that pronargs isn't negative,
and by changing MemSet to memset. (It appears that either change is
enough to quiet the warning at -O2, but let's do both to be sure.)
We had "short *mdy" in the extern declarations, but "short mdy[3]"
in the actual function definitions. Per C99 these are equivalent,
but recent versions of gcc have started to issue warnings about
the inconsistency. Clean it up before the warnings get any more
widespread.
Back-patch, in case anyone wants to build older PG versions with
bleeding-edge compilers.
Discussion: https://postgr.es/m/2401575.1611764534@sss.pgh.pa.us
doConnect() never returns connections in state CONNECTION_BAD, so
checking for that is pointless. Remove the code that does.
This code has been dead since ba708ea3dc84, 20 years ago.
Discussion: https://postgr.es/m/20210126195224.GA20361@alvherre.pgsql
Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
When reporting connection errors, we might show a database name in the
message that's not the one we actually tried to connect to, if the
database was taken from libpq defaults instead of from user parameters.
Fix such error messages to use PQdb(), which reports the correct name.
(But, per commit 2930c05634bc, make sure not to try to print NULL.)
Apply to branches 9.5 through 13. Branch master has already been
changed differently by commit 58cd8dca3de0.
Reported-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://postgr.es/m/CA+TgmobssJ6rS22dspWnu-oDxXevGmhMD8VcRBjmj-b9UDqRjw@mail.gmail.com
The loops to identify word boundaries could access past the end of
the input string. Likely that would never result in an actual
crash, but it makes valgrind unhappy.
The logic to try different numbers of words didn't work when the
input has two words but we only have a match to the first, eg
"\h with select". (We must "continue" the pass loop, not "break".)
The logic to compute nl_count was bizarrely managed, and in at
least two code paths could end up calling PageOutput with
nl_count = 0, resulting in failing to paginate output that should
have been fed to the pager. Also, in v12 and up, the nl_count
calculation hadn't been updated to account for the addition of a URL.
The PQExpBuffer holding the command syntax details wasn't freed,
resulting in a session-lifespan memory leak.
While here, improve some comments, choose a more descriptive name
for a variable, fix inconsistent datatype choice for another variable.
Per bug #16837 from Alexander Lakhin. This code is very old,
so back-patch to all supported branches.
Kyotaro Horiguchi and Tom Lane
Discussion: https://postgr.es/m/16837-479bcd56040c71b3@postgresql.org
Both heapgettup() and heapgettup_pagemode() incorrectly set the first page
to scan in a backward scan in which the number of pages to scan was
specified by heap_setscanlimits(). The code incorrectly started the scan
at the end of the relation when startBlk was 0, or otherwise at
startBlk - 1, neither of which is correct when only scanning a subset of
pages.
The fix here checks if heap_setscanlimits() has changed the number of
pages to scan and if so we set the first page to scan as the final page in
the specified range during backward scans.
Proper adjustment of this code was forgotten when heap_setscanlimits() was
added in 7516f5259 back in 9.5. However, practice, nowhere in core code
performs backward scans after having used heap_setscanlimits(), yet, it is
possible an extension uses the heap functions in this way, hence
backpatch.
An upcoming patch does use heap_setscanlimits() with backward scans, so
this must be fixed before that can go in.
Author: David Rowley
Discussion: https://postgr.es/m/CAApHDvpGc9h0_oVD2CtgBcxCS1N-qDYZSeBRnUh+0CWJA9cMaA@mail.gmail.com
Backpatch-through: 9.5, all supported versions
DST law changes in Russia (Volgograd zone) and South Sudan.
Historical corrections for Australia, Bahamas, Belize, Bermuda,
Ghana, Israel, Kenya, Nigeria, Palestine, Seychelles, and Vanuatu.
Notably, the Australia/Currie zone has been corrected to the point
where it is identical to Australia/Hobart.
In light of recent discussions, we should instruct people to
install Apple's command line tools; installing Xcode is secondary.
Also, fix sample command for finding out the default sysroot,
as we now know that the command originally recommended can give
a result that doesn't match your OS version.
Also document the workaround to use if you really don't want
configure to select a sysroot at all.
Discussion: https://postgr.es/m/20210119111625.20435-1-james.hilliard1@gmail.com
This text claimed that the reconnection would occur "to the same
server", but there is no such guarantee in the code, nor would
insisting on that be an improvement.
Back-patch to v10 where multi-host connection strings were added.
Discussion: https://postgr.es/m/1095901.1611268376@sss.pgh.pa.us
It emerges that in some phases of the moon (perhaps to do with
directory entry order?), xcrun will report that the SDK path is
/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk
which is normally a symlink to a version-numbered sibling directory.
Our heuristic to skip non-version-numbered pathnames was rejecting
that, which is the wrong thing to do. We'd still like to end up
with a version-numbered PG_SYSROOT value, but we can have that by
dereferencing the symlink.
Like the previous fix, back-patch to all supported versions.
Discussion: https://postgr.es/m/522433.1611089678@sss.pgh.pa.us
By default VACUUM will skip pages that it can't immediately get
exclusive access to, which means that even activities as harmless
and unpredictable as checkpoint buffer writes might prevent a page
from being processed. Ordinarily this is no big deal, but we have
a small number of test cases that examine the results of VACUUM's
processing and therefore will fail if the page of interest is skipped.
This seems to be the explanation for some rare buildfarm failures.
To fix, add the DISABLE_PAGE_SKIPPING option to the VACUUM commands
in tests where this could be an issue.
In passing, remove a duplicated query in pageinspect/sql/page.sql.
Back-patch as necessary (some of these cases are as old as v10).
Discussion: https://postgr.es/m/413923.1611006484@sss.pgh.pa.us
Specifying duplicated objects in this command would lead to unique
constraint violations in pg_default_acl or "tuple already updated by
self" errors. Similarly to GRANT/REVOKE, increment the command ID after
each subcommand processing to allow this case to work transparently.
A regression test is added by tweaking one of the existing queries of
privileges.sql to stress this case.
Reported-by: Andrus
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/ae2a7dc1-9d71-8cba-3bb9-e4cb7eb1f44e@hot.ee
Backpatch-through: 9.5
Somebody extended search_plan_tree() to treat MergeAppend exactly
like Append, which is 100% wrong, because unlike Append we can't
assume that only one input node is actively returning tuples.
Hence a cursor using a MergeAppend across a UNION ALL or inheritance
tree could falsely match a WHERE CURRENT OF query at a row that
isn't actually the cursor's current output row, but coincidentally
has the same TID (in a different table) as the current output row.
Delete the faulty code; this means that such a case will now return
an error like 'cursor "foo" is not a simply updatable scan of table
"bar"', instead of silently misbehaving. Users should not find that
surprising though, as the same cursor query could have failed that way
already depending on the chosen plan. (It would fail like that if the
sort were done with an explicit Sort node instead of MergeAppend.)
Expand the clearly-inadequate commentary to be more explicit about
what this code is doing, in hopes of forestalling future mistakes.
It's been like this for awhile, so back-patch to all supported
branches.
Discussion: https://postgr.es/m/482865.1611075182@sss.pgh.pa.us
execCurrent.c's search_plan_tree() assumed that ForeignScanStates
and CustomScanStates necessarily have a valid ss_currentRelation.
This is demonstrably untrue for postgres_fdw's remote join and
remote aggregation plans, and non-leaf custom scans might not have
an identifiable scan relation either. Avoid crashing by ignoring
such nodes when the field is null.
This solution will lead to errors like 'cursor "foo" is not a
simply updatable scan of table "bar"' in cases where maybe we
could have allowed WHERE CURRENT OF to work. That's not an issue
for postgres_fdw's usages, since joins or aggregations would render
WHERE CURRENT OF invalid anyway. But an otherwise-transparent
upper level custom scan node might find this annoying. When and if
someone cares to expend work on such a scenario, we could invent a
custom-scan-provider callback to determine what's safe.
Report and patch by David Geier, commentary by me. It's been like
this for awhile, so back-patch to all supported branches.
Discussion: https://postgr.es/m/0253344d-9bdd-11c4-7f0d-d88c02cd7991@swarm64.com
The context is an object that no longer bears some aclitem that it bore
initially. (A user issued REVOKE or GRANT statements upon the object.)
pg_dump is forming SQL to reproduce the object ACL. Since initdb
creates no ACL bearing GRANT OPTION, reaching this bug requires an
extension where the creation script establishes such an ACL. No PGXN
extension does that. If an installation did reach the bug, pg_dump
would have omitted a semicolon, causing a REVOKE and the next SQL
statement to fail. Separately, since the affected code exists to
eliminate an entire aclitem, it wants plain REVOKE, not REVOKE GRANT
OPTION FOR. Back-patch to 9.6, where commit
23f34fa4ba358671adab16773e79c17c92cbc870 first appeared.
Discussion: https://postgr.es/m/20210109102423.GA160022@rfd.leadboat.com
Every core SLRU wraps around. With the exception of pg_notify, the wrap
point can fall in the middle of a page. Account for this in the
PagePrecedes callback specification and in SimpleLruTruncate()'s use of
said callback. Update each callback implementation to fit the new
specification. This changes SerialPagePrecedesLogically() from the
style of asyncQueuePagePrecedes() to the style of CLOGPagePrecedes().
(Whereas pg_clog and pg_serial share a key space, pg_serial is nothing
like pg_notify.) The bug fixed here has the same symptoms and user
followup steps as 592a589a04bd456410b853d86bd05faa9432cbbb. Back-patch
to 9.5 (all supported versions).
Reviewed by Andrey Borodin and (in earlier versions) by Tom Lane.
Discussion: https://postgr.es/m/20190202083822.GC32531@gust.leadboat.com
Add a check that CREATE STATISTICS does not add extended statistics on
system catalogs, similarly to indexes etc. It can be overriden using
the allow_system_table_mods GUC.
This bug exists since 7b504eb282c, adding the extended statistics, so
backpatch all the way back to PostgreSQL 10.
Author: Tomas Vondra
Reported-by: Dean Rasheed
Backpatch-through: 10
Discussion: https://postgr.es/m/CAEZATCXAPrrOKwEsyZKQ4uzzJQWBCt6QAvOcgqRGdWwT1zb%2BrQ%40mail.gmail.com
In cases where Xcode is newer than the underlying macOS version,
asking xcodebuild for the SDK path will produce a pointer to the
SDK shipped with Xcode, which may end up building code that does
not work on the underlying macOS version. It appears that in
such cases, xcodebuild's answer also fails to match the default
behavior of Apple's compiler: assuming one has installed Xcode's
"command line tools", there will be an SDK for the OS's own version
in /Library/Developer/CommandLineTools, and the compiler will
default to using that. This is all pretty poorly documented,
but experimentation suggests that "xcrun --show-sdk-path" gives
the sysroot path that the compiler is actually using, at least
in some cases. Hence, try that first, but revert to xcodebuild
if xcrun fails (in very old Xcode, it is missing or lacks the
--show-sdk-path switch).
Also, "xcrun --show-sdk-path" may give a path that is valid but lacks
any OS version identifier. We don't really want that, since most
of the motivation for wiring -isysroot into the build flags at all
is to ensure that all parts of a PG installation are built against
the same SDK, even when considering extensions built later and/or on
a different machine. Insist on finding "N.N" in the directory name
before accepting the result. (Adding "--sdk macosx" to the xcrun
call seems to produce the same answer as xcodebuild, but usually
more quickly because it's cached, so we also try that as a fallback.)
The core reason why we don't want to use Xcode's default SDK in cases
like this is that Apple's technology for introducing new syscalls
does not play nice with Autoconf: for example, configure will think
that preadv/pwritev exist when using a Big Sur SDK, even when building
on an older macOS version where they don't exist. It'd be nice to
have a better solution to that problem, but this patch doesn't attempt
to fix that.
Per report from Sergey Shinderuk. Back-patch to all supported versions.
Discussion: https://postgr.es/m/ed3b8e5d-0da8-6ebd-fd1c-e0ac80a4b204@postgrespro.ru
This is the same fix as commit 9eabfe300 applied to INDEX ATTACH
entries, but for table-to-publication attachments. As in that
case, even though the backend doesn't record "ownership" of the
attachment, we still ought to label it in the dump archive with
the role name that should run the ALTER PUBLICATION command.
The existing behavior causes the ALTER to be done by the original
role that started the restore; that will usually work fine, but
there may be corner cases where it fails.
The bulk of the patch is concerned with changing struct
PublicationRelInfo to include a pointer to the associated
PublicationInfo object, so that we can get the owner's name
out of that when the time comes. While at it, I rewrote
getPublicationTables() to do just one query of pg_publication_rel,
not one per table.
Back-patch to v10 where this code was introduced.
Discussion: https://postgr.es/m/1165710.1610473242@sss.pgh.pa.us
