--- we were not using the scandir pattern filtering anyway.  This also
removes the scandir requirement in configure.

This gets rid of an impressive amount of duplicative code, with only
minimal behavior changes.  DROP FOREIGN DATA WRAPPER now requires object
ownership rather than superuser privileges, matching the documentation
we already have.  We also eliminate the historical warning about dropping
a built-in function as unuseful.  All operations are now performed in the
same order for all object types handled by dropcmds.c.

KaiGai Kohei, with minor revisions by me

Use of anynonarray was a crude hack to get around ambiguity versus the
array inclusion operators of the same names.  My previous patch to extend
the parser's type resolution heuristics makes that unnecessary, so use
the more general declaration instead.  This eliminates a wart that these
operators couldn't be used with ranges over arrays, which are otherwise
supported just fine.

Also, mark range_before and range_after as commutator operators,
per discussion with Jeff Davis.

For a very long time, one of the parser's heuristics for resolving
ambiguous operator calls has been to assume that unknown-type literals are
of the same type as the other input (if it's known).  However, this was
only used in the first step of quickly checking for an exact-types match,
and thus did not help in resolving matches that require coercion, such as
matches to polymorphic operators.  As we add more polymorphic operators,
this becomes more of a problem.  This patch adds another use of the same
heuristic as a last-ditch check before failing to resolve an ambiguous
operator or function call.  In particular this will let us define the range
inclusion operator in a less limited way (to come in a follow-on patch).

Also improve its comments and related regression tests.

Jeff Davis, with some further adjustments by Tom

Same as previous patch, but give it actual thought this time

It's been deprecated for ages according to Tom, and it breaks now given
the previous patch anyway.

Per buildfarm

A very long time ago, language names were specified as literals rather
than identifiers, so this code was added to do case-folding.  But that
style has ben deprecated for many years so this isn't needed any more.
Language names will still be downcased when specified as unquoted
identifiers, but quoted identifiers or the old style using string
literals will be left as-is.

pattern, which is used on PG 9.1 and HEAD (but not pre-9.1).  Fixes
crash on Windows.

Backpatched to 9.1.

Reported by Mark Dilger

This gives a much better error message when the object of interest is
concurrently dropped and avoids needlessly failing when the object of
interest is concurrently dropped and recreated.  It also improves the
behavior of two concurrent DROP IF EXISTS operations targeted at the
same object; as before, one will drop the object, but now the other
will emit the usual NOTICE indicating that the object does not exist,
instead of rolling back.  As a fringe benefit, it's also slightly
less code.

Fix assorted infelicities, such as dependency on OIDs that aren't
hardwired, as well as outright misdeclaration of daterange_canonical(),
which resulted in crashes if you invoked it directly.  Add some more
regression tests to try to catch similar mistakes in future.

This can change the meaning of queries, if the blank line happens to
occur in the middle of a quoted literal, as per complaint from Tomas Vondra.

Back-patch to all supported branches.

Cache the the element type's I/O info across calls, not only the range
type's info.  In passing, also clean up hash_range a bit more.

Move the responsibility for caching specialized information about range
types into the type cache, so that the catalog lookups only have to occur
once per session.  Rearrange APIs a bit so that fn_extra caching is
actually effective in the GiST support code.  (Use of OidFunctionCallN is
bad enough for performance in itself, but it also prevents the function
from exploiting fn_extra caching.)

The range I/O functions are still not very bright about caching repeated
lookups, but that seems like material for a separate patch.

Also, avoid unnecessary use of memcpy to fetch/store the range type OID and
flags, and don't use the full range_deserialize machinery when all we need
to see is the flags value.

Also fix API error in range_gist_penalty --- it was failing to set *penalty
for any case involving an empty range.

A range type whose element type has 'd' alignment must have 'd' alignment
itself, else there is no guarantee that the element value can be used
in-place.  (Because range_deserialize uses att_align_pointer which forcibly
aligns the given pointer, violations of this rule did not lead to SIGBUS
but rather to garbage data being extracted, as in one of the added
regression test cases.)

Also, you can't put a toast pointer inside a range datum, since the
referenced value could disappear with the range datum still present.
For consistency with the handling of arrays and records, I also forced
decompression of in-line-compressed bound values.  It would work to store
them as-is, but our policy is to avoid situations that might result in
double compression.

Add assorted regression tests for this, and bump catversion because of
fixes to built-in pg_type entries.

Also some marginal cleanup of inconsistent/unnecessary error checks.

This is mostly to add some sanity checking for the pg_range catalog.

Change range_lower and range_upper to return NULL rather than throwing an
error when the input range is empty or the relevant bound is infinite.  Per
discussion, throwing an error seems likely to be unduly hard to work with.
Also, this is more consistent with the behavior of the constructors, which
treat NULL as meaning an infinite bound.

Change range_before, range_after, range_adjacent to return false rather
than throwing an error when one or both input ranges are empty.

The original definition is unnecessarily difficult to use, and also can
result in undesirable planner failures since the planner could try to
compare an empty range to something else while deriving statistical
estimates.  (This was, in fact, the cause of repeatable regression test
failures on buildfarm member jaguar, as well as intermittent failures
elsewhere.)

Also tweak rangetypes regression test to not drop all the objects it
creates, so that the final state of the regression database contains
some rangetype objects for pg_dump testing.

No functional changes in this commit (except I could not resist the
temptation to re-word a couple of error messages).  This is just manual
cleanup after pgindent to make the code look reasonably like other PG
code, in preparation for more detailed code review to come.

Previously we waited for wal_writer_delay before flushing WAL. Now
we also wake WALWriter as soon as a WAL buffer page has filled.
Significant effect observed on performance of asynchronous commits
by Robert Haas, attributed to the ability to set hint bits on tuples
earlier and so reducing contention caused by clog lookups.

This seems to have been just an oversight in previous foreign-table work.
A quick grep didn't turn up any other places where RELKIND_FOREIGN_TABLE
was obviously omitted.

One change noted by Alexander Soudakov, the other by me.
Back-patch to 9.1.

This adds the "auto" option to the \x command, which switches to the
expanded mode when the normal output would be wider than the screen.

reviewed by Noah Misch

If it turns out we've locked the wrong OID, release the old lock.  In
most cases, it's pretty harmless to retain the extra lock, but this
seems tidier and avoids using lock table slots unnecessarily.

Per discussion with Tom Lane.

Report and patch by Josh Kupershmidt; comment revisions by me.

Previously, you'd get "function pg_catalog.pg_get_functiondef(integer) does
not exist", which is at best rather unprofessional-looking.  Back-patch
to 8.4 where \ef was introduced.

Josh Kupershmidt

This reverts commit 0180bd61.
contrib/userlock is gone, but user-level locking still exists,
and is exposed via the pg_advisory* family of functions.

If malloc(0) returns NULL, the binary search in findSecLabels() will
probably go into an infinite loop when there are no security labels,
because NULL-1 is greater than NULL after wraparound.

(We've seen this pathology before ... I wonder whether there's a way to
detect the class of bugs automatically?)

Diagnosis and patch by Steve Singer, cosmetic adjustments by me

Several server header files would not be installed in vpath builds
because they live in the build directory.

Backpatch to 9.1.

Mark Hills

I got alignment wrong in the redo routine. Spotted by redoing the log
genereated by copy regression test.

Forgot to call RestoreBkpBlocks() in the redo-function, as pointed out by
Simon Riggs. In redo of a regular heap insert, it's taken care of in
heap_redo(), but this new record type uses the heap2 RM, and heap2_redo()
does not take care of that for you.

Also, failed to reset the vmbuffer and all_visibile_cleared local variables
after switching to a new buffer.