Commit Graph

42876 Commits

Author SHA1 Message Date
Robert Haas a5775991bb Remove no-longer-needed compatibility code for hash indexes.
Because commit ea69a0dead bumped the
HASH_VERSION, we don't need to worry about PostgreSQL 10 seeing
bucket pages from earlier versions.

Amit Kapila

Discussion: http://postgr.es/m/CAA4eK1LAo4DGwh+mi-G3U8Pj1WkBBeFL38xdCnUHJv1z4bZFkQ@mail.gmail.com
2017-05-09 23:44:21 -04:00
Robert Haas df1a4eba94 Fix typos in comments.
Etsuro Fujita

Discussion: http://postgr.es/m/968d99bf-0fa8-085b-f0a1-a379f8d661ff@lab.ntt.co.jp
2017-05-09 23:40:08 -04:00
Robert Haas 9e6104c667 Prohibit transition tables on views and foreign tables.
Thomas Munro, per off-list report from Prabhat Sabu.  Changes
to the message wording for consistency with the existing
relkind check for partitioned tables by me.

Discussion: http://postgr.es/m/CAEepm=2xJFFpGM+N=gpWx-9Nft2q1oaFZX07_y23AHCrJQLt0g@mail.gmail.com
2017-05-09 23:34:02 -04:00
Robert Haas 29fd3d9da0 Don't permit transition tables with TRUNCATE triggers.
Prior to this prohibition, such a trigger caused a crash.

Thomas Munro, per a report from Neha Sharma.  I added a
regression test.

Discussion: http://postgr.es/m/CAEepm=0VR5W-N38eTkO_FqJbGqQ_ykbBRmzmvHyxDhy1p=0Csw@mail.gmail.com
2017-05-09 23:24:23 -04:00
Robert Haas 304007d9f1 Pass EXEC_FLAG_REWIND when initializing a tuplestore scan.
Since a rescan is possible, we must be able to rewind.

Thomas Munro, per a report from Prabhat Sabu

Discussion: http://postgr.es/m/CAEepm=2=Uv5fm=exqL+ygBxaO+-tgmC=o+63H4zYAXi9HtXf1w@mail.gmail.com
2017-05-09 23:13:21 -04:00
Robert Haas 3439f84475 Disallow finite partition bound following earlier UNBOUNDED column.
Amit Langote, per an observation by me.

Discussion: http://postgr.es/m/CA+TgmoYWnV2GMnYLG-Czsix-E1WGAbo4D+0tx7t9NdfYBDMFsA@mail.gmail.com
2017-05-09 22:41:12 -04:00
Peter Eisentraut 489b96e80b Improve memory use in logical replication apply
Previously, the memory used by the logical replication apply worker for
processing messages would never be freed, so that could end up using a
lot of memory.  To improve that, change the existing ApplyContext memory
context to ApplyMessageContext and reset that after every
message (similar to MessageContext used elsewhere).  For consistency of
naming, rename the ApplyCacheContext to ApplyContext.

Author: Stas Kelvich <s.kelvich@postgrespro.ru>
2017-05-09 14:51:49 -04:00
Alvaro Herrera e0bf16060b Ignore PQcancel errors properly
Add a (void) cast to all PQcancel() calls that purposefully don't check
the return value, to keep compilers and static checkers happy.

Per Coverity.
2017-05-09 14:58:51 -03:00
Peter Eisentraut 26aa1cf376 pg_dump: Add --no-subscriptions option
Author: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Petr Jelinek <petr.jelinek@2ndquadrant.com>
2017-05-09 10:58:06 -04:00
Peter Eisentraut ab178bb2f4 doc: Add info about replication slot management
Add some more information about managing replication slots associated
with logical replication subscriptions.
2017-05-09 10:25:26 -04:00
Peter Eisentraut 013c1178fd Remove the NODROP SLOT option from DROP SUBSCRIPTION
It turned out this approach had problems, because a DROP command should
not have any options other than CASCADE and RESTRICT.  Instead, always
attempt to drop the slot if there is one configured, but also add an
ALTER SUBSCRIPTION action to set the slot to NONE.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/29431.1493730652@sss.pgh.pa.us
2017-05-09 10:20:42 -04:00
Bruce Momjian c4c493fd35 pgindent: use HTTP instead of FTP to retrieve pg_bsd_indent src
FTP support will be removed from ftp.postgresql.org in months, but http
still works.  Typedefs already used http.
2017-05-09 09:28:44 -04:00
Tom Lane da07596006 Further patch rangetypes_selfuncs.c's statistics slot management.
Values in a STATISTIC_KIND_RANGE_LENGTH_HISTOGRAM slot are float8,
not of the type of the column the statistics are for.

This bug is at least partly the fault of sloppy specification comments
for get_attstatsslot()/free_attstatsslot(): the type OID they want is that
of the stavalues entries, not of the underlying column.  (I double-checked
other callers and they seem to get this right.)  Adjust the comments to be
more correct.

Per buildfarm.

Security: CVE-2017-7484
2017-05-08 15:03:14 -04:00
Peter Eisentraut fe974cc5a6 Check connection info string in ALTER SUBSCRIPTION
Previously it would allow an invalid connection string to be set.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: tushar <tushar.ahuja@enterprisedb.com>
2017-05-08 14:01:00 -04:00
Tom Lane c89d2d0204 Last-minute updates for release notes.
Security: CVE-2017-7484, CVE-2017-7485, CVE-2017-7486
2017-05-08 12:57:27 -04:00
Peter Eisentraut 9a591c1bcc Fix statistics reporting in logical replication workers
This new arrangement ensures that statistics are reported right after
commit of transactions.  The previous arrangement didn't get this quite
right and could lead to assertion failures.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: Erik Rijkers <er@xs4all.nl>
2017-05-08 12:10:22 -04:00
Tom Lane b6576e5914 Fix possibly-uninitialized variable.
Oversight in e2d4ef8de et al (my fault not Peter's).  Per buildfarm.

Security: CVE-2017-7484
2017-05-08 11:18:40 -04:00
Noah Misch 3eefc51053 Match pg_user_mappings limits to information_schema.user_mapping_options.
Both views replace the umoptions field with NULL when the user does not
meet qualifications to see it.  They used different qualifications, and
pg_user_mappings documented qualifications did not match its implemented
qualifications.  Make its documentation and implementation match those
of user_mapping_options.  One might argue for stronger qualifications,
but these have long, documented tenure.  pg_user_mappings has always
exhibited this problem, so back-patch to 9.2 (all supported versions).

Michael Paquier and Feike Steenbergen.  Reviewed by Jeff Janes.
Reported by Andrew Wheelwright.

Security: CVE-2017-7486
2017-05-08 07:24:24 -07:00
Noah Misch 0170b10dff Restore PGREQUIRESSL recognition in libpq.
Commit 65c3bf19fd moved handling of the,
already then, deprecated requiressl parameter into conninfo_storeval().
The default PGREQUIRESSL environment variable was however lost in the
change resulting in a potentially silent accept of a non-SSL connection
even when set.  Its documentation remained.  Restore its implementation.
Also amend the documentation to mark PGREQUIRESSL as deprecated for
those not following the link to requiressl.  Back-patch to 9.3, where
commit 65c3bf1 first appeared.

Behavior has been more complex when the user provides both deprecated
and non-deprecated settings.  Before commit 65c3bf1, libpq operated
according to the first of these found:

  requiressl=1
  PGREQUIRESSL=1
  sslmode=*
  PGSSLMODE=*

(Note requiressl=0 didn't override sslmode=*; it would only suppress
PGREQUIRESSL=1 or a previous requiressl=1.  PGREQUIRESSL=0 had no effect
whatsoever.)  Starting with commit 65c3bf1, libpq ignored PGREQUIRESSL,
and order of precedence changed to this:

  last of requiressl=* or sslmode=*
  PGSSLMODE=*

Starting now, adopt the following order of precedence:

  last of requiressl=* or sslmode=*
  PGSSLMODE=*
  PGREQUIRESSL=1

This retains the 65c3bf1 behavior for connection strings that contain
both requiressl=* and sslmode=*.  It retains the 65c3bf1 change that
either connection string option overrides both environment variables.
For the first time, PGSSLMODE has precedence over PGREQUIRESSL; this
avoids reducing security of "PGREQUIRESSL=1 PGSSLMODE=verify-full"
configurations originating under v9.3 and later.

Daniel Gustafsson

Security: CVE-2017-7485
2017-05-08 07:24:24 -07:00
Bruce Momjian 74cadeaa2f doc: add Simon Riggs to VACUUM VERBOSE PG 10 release note item
Reported-by: Masahiko Sawada
2017-05-08 09:50:16 -04:00
Peter Eisentraut e2d4ef8de8 Add security checks to selectivity estimation functions
Some selectivity estimation functions run user-supplied operators over
data obtained from pg_statistic without security checks, which allows
those operators to leak pg_statistic data without having privileges on
the underlying tables.  Fix by checking that one of the following is
satisfied: (1) the user has table or column privileges on the table
underlying the pg_statistic data, or (2) the function implementing the
user-supplied operator is leak-proof.  If neither is satisfied, planning
will proceed as if there are no statistics available.

At least one of these is satisfied in most cases in practice.  The only
situations that are negatively impacted are user-defined or
not-leak-proof operators on a security-barrier view.

Reported-by: Robert Haas <robertmhaas@gmail.com>
Author: Peter Eisentraut <peter_e@gmx.net>
Author: Tom Lane <tgl@sss.pgh.pa.us>

Security: CVE-2017-7484
2017-05-08 09:26:32 -04:00
Heikki Linnakangas eb61136dc7 Remove support for password_encryption='off' / 'plain'.
Storing passwords in plaintext hasn't been a good idea for a very long
time, if ever. Now seems like a good time to finally forbid it, since we're
messing with this in PostgreSQL 10 anyway.

Remove the CREATE/ALTER USER UNENCRYPTED PASSSWORD 'foo' syntax, since
storing passwords unencrypted is no longer supported. ENCRYPTED PASSWORD
'foo' is still accepted, but ENCRYPTED is now just a noise-word, it does
the same as just PASSWORD 'foo'.

Likewise, remove the --unencrypted option from createuser, but accept
--encrypted as a no-op for backward compatibility. AFAICS, --encrypted was
a no-op even before this patch, because createuser encrypted the password
before sending it to the server even if --encrypted was not specified. It
added the ENCRYPTED keyword to the SQL command, but since the password was
already in encrypted form, it didn't make any difference. The documentation
was not clear on whether that was intended or not, but it's moot now.

Also, while password_encryption='on' is still accepted as an alias for
'md5', it is now marked as hidden, so that it is not listed as an accepted
value in error hints, for example. That's not directly related to removing
'plain', but it seems better this way.

Reviewed by Michael Paquier

Discussion: https://www.postgresql.org/message-id/16e9b768-fd78-0b12-cfc1-7b6b7f238fde@iki.fi
2017-05-08 11:26:07 +03:00
Simon Riggs 1f30295eab Remove poorly worded and duplicated comment
Move line of code to avoid need for duplicated comment

Brought to attention by Masahiko Sawada
2017-05-08 08:49:28 +01:00
Tom Lane 27dae036a5 Release notes for 9.6.3, 9.5.7, 9.4.12, 9.3.17, 9.2.21. 2017-05-07 16:56:02 -04:00
Tom Lane 86713deecd Third pass on 9.6.3 release notes.
Add updates for recent commits.

In passing, credit Etsuro Fujita for his work on the postgres_fdw
query cancel feature in 9.6; I seem to have missed that in the
original drafting of the 9.6 notes.
2017-05-07 14:43:04 -04:00
Heikki Linnakangas 0186ded546 Fix memory leaks if random salt generation fails.
In the backend, this is just to silence coverity warnings, but in the
frontend, it's a genuine leak, even if extremely rare.

Spotted by Coverity, patch by Michael Paquier.
2017-05-07 19:58:21 +03:00
Tom Lane a54d5875fe Guard against null t->tm_zone in strftime.c.
The upstream IANA code does not guard against null TM_ZONE pointers in this
function, but in our code there is such a check in the other pre-existing
use of t->tm_zone.  We do have some places that set pg_tm.tm_zone to NULL.
I'm not entirely sure it's possible to reach strftime with such a value,
but I'm not sure it isn't either, so be safe.

Per Coverity complaint.
2017-05-07 12:33:12 -04:00
Tom Lane d4e59c5521 Install the "posixrules" timezone link in MSVC builds.
Somehow, we'd missed ever doing this.  The consequences aren't too
severe: basically, the timezone library would fall back on its hardwired
notion of the DST transition dates to use for a POSIX-style zone name,
rather than obeying US/Eastern which is the intended behavior.  The net
effect would only be to obey current US DST law further back than it
ought to apply; so it's not real surprising that nobody noticed.

David Rowley, per report from Amit Kapila

Discussion: https://postgr.es/m/CAA4eK1LC7CaNhRAQ__C3ht1JVrPzaAXXhEJRnR5L6bfYHiLmWw@mail.gmail.com
2017-05-07 11:57:41 -04:00
Tom Lane 5788a5670e Restore fullname[] contents before falling through in pg_open_tzfile().
Fix oversight in commit af2c5aa88: if the shortcut open() doesn't work,
we need to reset fullname[] to be just the name of the toplevel tzdata
directory before we fall through into the pre-existing code.  This failed
to be exposed in my (tgl's) testing because the fall-through path is
actually never taken under normal circumstances.

David Rowley, per report from Amit Kapila

Discussion: https://postgr.es/m/CAA4eK1LC7CaNhRAQ__C3ht1JVrPzaAXXhEJRnR5L6bfYHiLmWw@mail.gmail.com
2017-05-07 11:34:31 -04:00
Bruce Momjian 628462bda9 doc PG 10: adjustments to BRIN, WAL, JSON, XML items, syntax
Reported-by: Alvaro Herrera
2017-05-06 23:32:03 -04:00
Stephen Frost 09f8421819 pg_dump: Don't leak memory in buildDefaultACLCommands()
buildDefaultACLCommands() didn't destroy the string buffer created in
certain cases, leading to a memory leak.  Fix by destroying the buffer
before returning from the function.

Spotted by Coverity.

Author: Michael Paquier

Back-patch to 9.6 where buildDefaultACLCommands() was added.
2017-05-06 22:58:12 -04:00
Stephen Frost aa5d3c0b3f RLS: Fix ALL vs. SELECT+UPDATE policy usage
When we add the SELECT-privilege based policies to the RLS with check
options (such as for an UPDATE statement, or when we have INSERT ...
RETURNING), we need to be sure and use the 'USING' case if the policy is
actually an 'ALL' policy (which could have both a USING clause and an
independent WITH CHECK clause).

This could result in policies acting differently when built using ALL
(when the ALL had both USING and WITH CHECK clauses) and when building
the policies independently as SELECT and UPDATE policies.

Fix this by adding an explicit boolean to add_with_check_options() to
indicate when the USING policy should be used, even if the policy has
both USING and WITH CHECK policies on it.

Reported by: Rod Taylor

Back-patch to 9.5 where RLS was introduced.
2017-05-06 21:46:35 -04:00
Andres Freund b58c433ef9 Fix duplicated words in comment.
Reported-By: Peter Geoghegan
Discussion: https://postgr.es/m/CAH2-Wzn3rY2N0gTWndaApD113T+O8L6oz8cm7_F3P8y4awdoOg@mail.gmail.com
Backpatch: no, only present in master
2017-05-06 17:03:45 -07:00
Andres Freund e6c44eef55 Fix off-by-one possibly leading to skipped XLOG_RUNNING_XACTS records.
Since 6ef2eba3f5 ("Skip checkpoints, archiving on idle systems."),
GetLastImportantRecPtr() is used to avoid performing superfluous
checkpoints, xlog switches, running-xact records when the system is
idle.  Unfortunately the check concerning running-xact records had a
off-by-one error, leading to such records being potentially skipped
when only a single record has been inserted since the last
running-xact record.

An alternative approach would have been to change
GetLastImportantRecPtr()'s definition to point to the end of records,
but that would make the checkpoint code more complicated.

Author: Andres Freund
Discussion: https://postgr.es/m/20170505012447.wsrympaxnfis6ojt@alap3.anarazel.de
Backpatch: no, code only present in master
2017-05-06 16:55:07 -07:00
Tom Lane 334b82cd56 Second pass on 9.6.3 release notes.
Improve description of logical decoding snapshot issues, per suggestion
from Petr Jelinek.  Mention possible need to re-sync logical replicas
as a post-upgrade task.  Minor copy-editing for some other items.
2017-05-06 16:28:20 -04:00
Tom Lane a9c6d70435 Document current_role.
This system function has been there a very long time, but somehow escaped
being listed in func.sgml.

Fabien Coelho and Tom Lane

Discussion: https://postgr.es/m/alpine.DEB.2.20.1705061027580.3896@lancre
2017-05-06 14:19:47 -04:00
Tom Lane 54dbd4dc78 First-draft release notes for 9.6.3.
As usual, the release notes for other branches will be made by cutting
these down, but put them up for community review first.  Note there
are some entries that really only apply to pre-9.6 branches.
2017-05-05 19:33:34 -04:00
Tom Lane b3a47cdfd6 Suppress compiler warning about unportable pointer value.
Setting a pointer value to "0xdeadbeef" draws a warning from some
compilers, and for good reason.  Be less cute and just set it to NULL.

In passing make some other cosmetic adjustments nearby.

Discussion: https://postgr.es/m/CAJrrPGdW3EkU-CRobvVKYf3fJuBdgWyuGeAbNzAQ4yBh+bfb_Q@mail.gmail.com
2017-05-05 12:46:04 -04:00
Alvaro Herrera 14722c69f9 Allow MSVC to build with Tcl 8.6.
Commit eaba54c20c added support for Tcl 8.6 for configure-supported
platforms after verifying that pltcl works without further changes, but
the MSVC tooling wasn't updated accordingly.  Update MSVC to match,
restructuring the code to avoid duplicating the logic for every Tcl
version supported.

Backpatch to all live branches, like eaba54c20c.  In 9.4 and previous,
change the patch to use backslashes rather than forward, as in the rest
of the file.

Reported by Paresh More, who also tested the patch I provided.
Discussion: https://postgr.es/m/CAAgiCNGVw3ssBtSi3ZNstrz5k00ax=UV+_ZEHUeW_LMSGL2sew@mail.gmail.com
2017-05-05 12:38:29 -03:00
Peter Eisentraut 086221cf6b Prevent panic during shutdown checkpoint
When the checkpointer writes the shutdown checkpoint, it checks
afterwards whether any WAL has been written since it started and throws
a PANIC if so.  At that point, only walsenders are still active, so one
might think this could not happen, but walsenders can also generate WAL,
for instance in BASE_BACKUP and certain variants of
CREATE_REPLICATION_SLOT.  So they can trigger this panic if such a
command is run while the shutdown checkpoint is being written.

To fix this, divide the walsender shutdown into two phases.  First, the
postmaster sends a SIGUSR2 signal to all walsenders.  The walsenders
then put themselves into the "stopping" state.  In this state, they
reject any new commands.  (For simplicity, we reject all new commands,
so that in the future we do not have to track meticulously which
commands might generate WAL.)  The checkpointer waits for all walsenders
to reach this state before proceeding with the shutdown checkpoint.
After the shutdown checkpoint is done, the postmaster sends
SIGINT (previously unused) to the walsenders.  This triggers the
existing shutdown behavior of sending out the shutdown checkpoint record
and then terminating.

Author: Michael Paquier <michael.paquier@gmail.com>
Reported-by: Fujii Masao <masao.fujii@gmail.com>
2017-05-05 10:31:42 -04:00
Magnus Hagander 499ae5f5db Fix wording in pg_upgrade docs
Author: Daniel Gustafsson
2017-05-05 12:42:21 +02:00
Magnus Hagander 28d1c8ccc8 Build pgoutput.dll in MSVC build
Without this, logical replication obviously does not work on Windows

MauMau, with clean.bet additions from me per note from Michael Paquier
2017-05-05 12:08:48 +02:00
Heikki Linnakangas 0557a5dc2c Make SCRAM salts and nonces longer.
The salt is stored base64-encoded. With the old 10 bytes raw length, it was
always padded to 16 bytes after encoding. We might as well use 12 raw bytes
for the salt, and it's still encoded into 16 bytes.

Similarly for the random nonces, use a raw length that's divisible by 3, so
that there's no padding after base64 encoding. Make the nonces longer while
we're at it. 10 bytes was probably enough to prevent replay attacks, but
there's no reason to be skimpy here.

Per suggestion from Álvaro Hernández Tortosa.

Discussion: https://www.postgresql.org/message-id/df8c6e27-4d8e-5281-96e5-131a4e638fc8@8kdata.com
2017-05-05 10:02:13 +03:00
Heikki Linnakangas e6e9c4da3a Misc cleanup of SCRAM code.
* Remove is_scram_verifier() function. It was unused.
* Fix sanitize_char() function, used in error messages on protocol
  violations, to print bytes >= 0x7F correctly.
* Change spelling of scram_MockSalt() function to be more consistent with
  the surroundings.
* Change a few more references to "server proof" to "server signature" that
  I missed in commit d981074c24.
2017-05-05 10:01:44 +03:00
Heikki Linnakangas 344a113079 Don't use SCRAM-specific "e=invalid-proof" on invalid password.
Instead, send the same FATAL message as with other password-based
authentication mechanisms. This gives a more user-friendly message:

psql: FATAL:  password authentication failed for user "test"

instead of:

psql: error received from server in SASL exchange: invalid-proof

Even before this patch, the server sent that FATAL message, after the
SCRAM-specific "e=invalid-proof" message. But libpq would stop at the
SCRAM error message, and not process the ErrorResponse that would come
after that. We could've taught libpq to check for an ErrorResponse after
failed authentication, but it's simpler to modify the server to send only
the ErrorResponse. The SCRAM specification allows for aborting the
authentication at any point, using an application-defined error mechanism,
like PostgreSQL's ErrorResponse. Using the e=invalid-proof message is
optional.

Reported by Jeff Janes.

Discussion: https://www.postgresql.org/message-id/CAMkU%3D1w3jQ53M1OeNfN8Cxd9O%2BA_9VONJivTbYoYRRdRsLT6vA@mail.gmail.com
2017-05-05 10:01:41 +03:00
Stephen Frost 44c528810a Change the way pg_dump retrieves partitioning info
This gets rid of the code that issued separate queries to retrieve the
partitioning parent-child relationship, parent partition key, and child
partition bound information.  With this patch, the information is
retrieved instead using the queries issued from getTables() and
getInherits(), which is both more efficient than the previous approach
and doesn't require any new code.

Since the partitioning parent-child relationship is now retrieved with
the same old code that handles inheritance, partition attributes receive
a proper flagInhAttrs() treatment (that it didn't receive before), which
is needed so that the inherited NOT NULL constraints are not emitted if
we already emitted it for the parent.

Also, fix a bug in pg_dump's --binary-upgrade code, which caused pg_dump
to emit invalid command to attach a partition to its parent.

Author: Amit Langote, with some additional changes by me.
2017-05-04 22:17:52 -04:00
Bruce Momjian 5469e44ffc doc: update PG 10 release notes
Mention vacuum verbose includes oldest xmin, BRIN index usage
estimation, and multi-column statistics.

Reported-by: Masahiko Sawada, Alvaro Herrera
2017-05-04 20:33:06 -04:00
Bruce Momjian 4f45beba7a doc: PG 10 release note updates for psql, GiST, and markup
Reported-by: Andrew Borodin, Fabien COELHO, Dagfinn Ilmari Mannsaker
2017-05-04 19:33:41 -04:00
Alvaro Herrera c22b59edd2 Credit Claudio as main author of feature 2017-05-04 17:50:54 -03:00
Tom Lane 3f074845a8 Fix pfree-of-already-freed-tuple when rescanning a GiST index-only scan.
GiST's getNextNearest() function attempts to pfree the previously-returned
tuple if any (that is, scan->xs_hitup in HEAD, or scan->xs_itup in older
branches).  However, if we are rescanning a plan node after ending a
previous scan early, those tuple pointers could be pointing to garbage,
because they would be pointing into the scan's pageDataCxt or queueCxt
which has been reset.  In a debug build this reliably results in a crash,
although I think it might sometimes accidentally fail to fail in
production builds.

To fix, clear the pointer field anyplace we reset a context it might
be pointing into.  This may be overkill --- I think probably only the
queueCxt case is involved in this bug, so that resetting in gistrescan()
would be sufficient --- but dangling pointers are generally bad news,
so let's avoid them.

Another plausible answer might be to just not bother with the pfree in
getNextNearest().  The reconstructed tuples would go away anyway in the
context resets, and I'm far from convinced that freeing them a bit earlier
really saves anything meaningful.  I'll stick with the original logic in
this patch, but if we find more problems in the same area we should
consider that approach.

Per bug #14641 from Denis Smirnov.  Back-patch to 9.5 where this
logic was introduced.

Discussion: https://postgr.es/m/20170504072034.24366.57688@wrigleys.postgresql.org
2017-05-04 13:59:39 -04:00