HP's web server has apparently become case-sensitive sometime recently.
Per bug #13479 from Daniel Abraham.  Corrected link identified by Alvaro.

1) Add sgml comments referencing commits. This is useful to search for
   missing items etc.

   The comments containing the commit notes are an excerpt from:
   git log --date=short \
       --pretty='format:%cd [%h] %<(8,trunc)%cN: %<(48,trunc)%s%n%n%w(,4,4)%b%n' \
       $(git merge-base origin/master upstream/REL9_4_STABLE)..origin/master
2) Improve a handful of existing notes
3) Add missing entries about a couple features.
4) Add a bunch of straight-forward FIXMEs

Let the hacking begin ...

Apparently, this is needed in some Solaris versions.

Author: Oskari Saarenmaa

Coverity rightly gripes that it's silly to have a test here when
the adjacent ExecEvalExpr() would choke on a NULL expression pointer.

Petr Jelinek

This seems useful to catch errors of the sort I just fixed, where
PageGetSpecialPointer is called before initializing the page.

After calling XLogInitBufferForRedo(), the page might be all-zeros if it was
not in page cache already. btree_xlog_unlink_page initialized the page
correctly, but it called PageGetSpecialPointer before initializing it, which
would lead to a corrupt page at WAL replay, if the unlinked page is not in
page cache.

Backpatch to 9.4, the bug came with the rewrite of B-tree page deletion.

Without this, we might access memory that's already been freed, or
leak memory if in the C locale.

Peter Geoghegan

I broke this with my WAL format refactoring patch. Before that, the metapage
was read from disk, and modified in-place regardless of the LSN. That was
always a bit silly, as there's no need to read the old page version from
disk disk when we're overwriting it anyway. So that was changed in 9.5, but
I failed to add a GinInitPage call to initialize the page-headers correctly.
Usually you wouldn't notice, because the metapage is already in the page
cache and is not zeroed.

One way to reproduce this is to perform a VACUUM on an already vacuumed
table (so that the vacuum has no real work to do), immediately after a
checkpoint, and then perform an immediate shutdown. After recovery, the
page headers of the metapage will be incorrectly all-zeroes.

Reported by Jeff Janes

Minor corrections and clarifications.  Notably, for stuff that got moved
out of contrib, make sure it's documented somewhere other than "Additional
Modules".

I'm sure these need more work, but that's all I have time for today.

Avoid memory leak from incorrect choice of how to free a StringInfo
(resetStringInfo doesn't do it).  Now that pg_split_opts doesn't scribble
on the optstr, mark that as "const" for clarity.  Attach the commentary in
protocol.sgml to the right place, and add documentation about the
user-visible effects of this change on postgres' -o option and libpq's
PGOPTIONS option.

_Asm_sched_fence() is just a compiler barrier, not a memory barrier. But
spinlock release on IA64 needs, at the very least, release
semantics. Use a full barrier instead.

This might be the cause for the occasional failures on buildfarm member
anole.

Discussion: 20150629101108.GB17640@alap3.anarazel.de

Source-Git-URL: git://git.postgresql.org/git/pgtranslation/messages.git
Source-Git-Hash: fb7e72f46cfafa1b5bfe4564d9686d63a1e6383f

Yeah, I know, pretty anal-retentive of me.  But we oughta find some
way to automate this for the .y and .l files.

As first committed, this view reported on the file contents as they were
at the last SIGHUP event.  That's not as useful as reporting on the current
contents, and what's more, it didn't work right on Windows unless the
current session had serviced at least one SIGHUP.  Therefore, arrange to
re-read the files when pg_show_all_settings() is called.  This requires
only minor refactoring so that we can pass changeVal = false to
set_config_option() so that it won't actually apply any changes locally.

In addition, add error reporting so that errors that would prevent the
configuration files from being loaded, or would prevent individual settings
from being applied, are visible directly in the view.  This makes the view
usable for pre-testing whether edits made in the config files will have the
desired effect, before one actually issues a SIGHUP.

I also added an "applied" column so that it's easy to identify entries that
are superseded by later entries; this was the main use-case for the original
design, but it seemed unnecessarily hard to use for that.

Also fix a 9.4.1 regression that allowed multiple entries for a
PGC_POSTMASTER variable to cause bogus complaints in the postmaster log.
(The issue here was that commit bf007a27 unintentionally reverted
3e3f6597, which suppressed any duplicate entries within
ParseConfigFp.  However, since the original coding of the pg_file_settings
view depended on such suppression *not* happening, we couldn't have fixed
this issue now without first doing something with pg_file_settings.
Now we suppress duplicates by marking them "ignored" within
ProcessConfigFileInternal, which doesn't hide them in the view.)

Lesser changes include:

Drive the view directly off the ConfigVariable list, instead of making a
basically-equivalent second copy of the data.  There's no longer any need
to hang onto the data permanently, anyway.

Convert show_all_file_settings() to do its work in one call and return a
tuplestore; this avoids risks associated with assuming that the GUC state
will hold still over the course of query execution.  (I think there were
probably latent bugs here, though you might need something like a cursor
on the view to expose them.)

Arrange to run SIGHUP processing in a short-lived memory context, to
forestall process-lifespan memory leaks.  (There is one known leak in this
code, in ProcessConfigDirectory; it seems minor enough to not be worth
back-patching a specific fix for.)

Remove mistaken assignment to ConfigFileLineno that caused line counting
after an include_dir directive to be completely wrong.

Add missed failure check in AlterSystemSetConfigFile().  We don't really
expect ParseConfigFp() to fail, but that's not an excuse for not checking.

When archive recovery and restartpoints were initially introduced,
checkpoint_segments was ignored on the grounds that the files restored from
archive don't consume any space in the recovery server. That was changed in
later releases, but even then it was arguably a feature rather than a bug,
as performing restartpoints as often as checkpoints during normal operation
might be excessive, but you might nevertheless not want to waste a lot of
space for pre-allocated WAL by setting checkpoint_segments to a high value.
But now that we have separate min_wal_size and max_wal_size settings, you
can bound WAL usage with max_wal_size, and still avoid consuming excessive
space usage by setting min_wal_size to a lower value, so that argument is
moot.

There are still some issues with actually limiting the space usage to
max_wal_size: restartpoints in recovery can only start after seeing the
checkpoint record, while a checkpoint starts flushing buffers as soon as
the redo-pointer is set. Restartpoint is paced to happen at the same
leisurily speed, determined by checkpoint_completion_target, as checkpoints,
but because they are started later, max_wal_size can be exceeded by upto
one checkpoint cycle's worth of WAL, depending on
checkpoint_completion_target. But that seems better than not trying at all,
and max_wal_size is a soft limit anyway.

The documentation already claimed that max_wal_size is obeyed in recovery,
so this just fixes the behaviour to match the docs. However, add some
weasel-words there to mention that max_wal_size may well be exceeded by
some amount in recovery.

Oops. I could swear I built the docs before pushing, but I guess not..

Seems like cheap insurance for WAL bugs. A spurious call to
XLogBeginInsert() in itself would be fairly harmless, but if there is any
data registered and the insertion is not completed/cancelled properly, there
is a risk that the data ends up in a wrong WAL record.

Per Jeff Janes's suggestion.

If data checksums or wal_log_hints is on, and a GIN page is split, the code
to find a new, empty, block was called after having already called
XLogBeginInsert(). That causes an assertion failure or PANIC, if finding the
new block involves updating a FSM page that had not been modified since last
checkpoint, because that update is WAL-logged, which calls XLogBeginInsert
again. Nested XLogBeginInsert calls are not supported.

To fix, rearrange GIN code so that XLogBeginInsert is called later, after
finding the victim buffers.

Reported by Jeff Janes.

If a file is removed from the source server, while pg_rewind is running, the
invocation of pg_read_binary_file() will fail. Use the just-added missing_ok
option to that function, to have it return NULL instead, and handle that
gracefully. And similarly for pg_ls_dir and pg_stat_file.

Reported by Fujii Masao, fix by Michael Paquier.

This makes it possible to use the functions without getting errors, if there
is a chance that the file might be removed or renamed concurrently.
pg_rewind needs to do just that, although this could be useful for other
purposes too. (The changes to pg_rewind to use these functions will come in
a separate commit.)

The read_binary_file() function isn't very well-suited for extensions.c's
purposes anymore, if it ever was. So bite the bullet and make a copy of it
in extension.c, tailored for that use case. This seems better than the
accidental code reuse, even if it's a some more lines of code.

Michael Paquier, with plenty of kibitzing by me.

The unit of measure is microseconds, not milliseconds.

Backpatch to 9.3 where the function and its comment were added.

A few places assumed they could pass NULL for the argtypes array when
looking up functions known to have zero arguments.  At first glance
it seems that this should be safe enough, since memcmp() is surely not
allowed to fetch any bytes if its count argument is zero.  However,
close reading of the C standard says that such calls have undefined
behavior, so we'd probably best avoid it.

Since the number of places doing this is quite small, and some other
places looking up zero-argument functions were already passing dummy
arrays, let's standardize on the latter solution rather than hacking
the function lookup code to avoid calling memcmp() in these cases.
I also added Asserts to catch any future violations of the new rule.

Given the utter lack of any evidence that this actually causes any
problems in the field, I don't feel a need to back-patch this change.

Per report from Piotr Stefaniak, though this is not his patch.

test_decoding used fastgetattr() to extract column values. That's wrong
when decoding updates and deletes if a table's replica identity is set
to FULL and new columns have been added since the old version of the
tuple was created. Due to the lack of a crosscheck with the datum's
natts values an invalid value will be output, leading to errors or
worse.

Bug: #13470
Reported-By: Krzysztof Kotlarski
Discussion: 20150626100333.3874.90852@wrigleys.postgresql.org

Backpatch to 9.4, where the feature, including the bug, was added.

Commit b89e1510 added the
ResolveCminCmaxDuringDecoding declaration to tqual.h, which uses an
HTAB parameter, without declaring HTAB.  It accidentally fails to
fail to build with current sources because a declaration happens to
be included, directly or indirectly, in all source files that
currently use tqual.h before tqual.h is first included, but we
shouldn't count on that.  Since an opaque declaration is enough
here, just use that, as was done in snapmgr.h.

Backpatch to 9.4, where the HTAB reference was added to tqual.h.

Etsuro Fujita

VACUUM FREEZE generated false cancelations of standby queries on an
otherwise idle master. Caused by an off-by-one error on cutoff_xid
which goes back to original commit.

Backpatch to all versions 9.0+

Analysis and report by Marco Nenciarini

Bug fix by Simon Riggs

Commit b488c580, which added the DDL command collection feature,
neglected to update the code that commit cac76582 had previously
added two weeks earlier for the TRANSFORM feature.

Reported by Michael Paquier.

There was a confusion about which block number to use when storing an
item's pointer in the revmap -- the revmap page's blkno was being used,
not the data page's blkno.

Spotted-by: Jeff Janes

Reported by Peter Geoghegan.

Don't apply rmtree(), which will gleefully remove an entire subtree,
and don't even apply unlink() unless it's symlink or a directory,
the only things that we expect to find.

Amit Kapila, with minor tweaks by me, per extensive discussions
involving Andrew Dunstan, Fujii Masao, and Heikki Linnakangas,
at least some of whom also reviewed the code.

Peter Geoghegan and Robert Haas

Spotted by Coverity and reported by Michael Paquier.  Per discussion,
we don't necessarily care about making Coverity happy in all such
instances, but we can go ahead and change them where it otherwise
seems to improve the code.

Per suggestions from Amit Langote and Álvaro Herrera.

Warning people that no WAL-logging will be done doesn't make sense
in this case.

Michael Paquier

Per discussion, LOG is just too chatty for something that will happen
as routinely as this.

Pavel Stehule