Fix some more bugs in contrib/xml2's xslt_process().

It failed to check for error return from xsltApplyStylesheet(), as reported
by Peter Gagarinov.  (So far as I can tell, libxslt provides no convenient
way to get a useful error message in failure cases.  There might be some
inconvenient way, but considering that this code is deprecated it's hard to
get enthusiastic about putting lots of work into it.  So I just made it say
"failed to apply stylesheet", in line with the existing error checks.)

While looking at the code I also noticed that the string returned by
xsltSaveResultToString was never freed, resulting in a session-lifespan
memory leak.

Back-patch to all supported versions.
Backpatch error message fix from 81f6bbe8ade8c90f23f9286ca9ca726d3e0e310f

Without this, pg_basebackup doesn't tell you why it failed when for example
there is a file in the data directory that the backend doesn't have
permissions to read.
Wake WALSender to reduce data loss at failover for async commit.
WALSender now woken up after each background flush by WALwriter, avoiding
multi-second replication delay for an all-async commit workload.
Replication delay reduced from 7s with default settings to 200ms, allowing
significantly reduced data loss at failover.

Andres Freund and Simon Riggs
Fix bug in early startup of Hot Standby with subtransactions.
When HS startup is deferred because of overflowed subtransactions, ensure
that we re-initialize KnownAssignedXids for when both existing and incoming
snapshots have non-zero qualifying xids.

Fixes bug #6661 reported by Valentine Gogichashvili.

Analysis and fix by Andres Freund
Prevent non-streaming replication connections from being selected sync slave

This prevents a pg_basebackup backup session that just does a base
backup (no xlog involved at all) from becoming the synchronous slave
and thus blocking all access while it runs.

Also fixes the problem when a higher priority slave shows up it would
become the sync standby before it has reached the STREAMING state, by
making sure we can only switch to a walsender that's actually STREAMING.

Fujii Masao
In pg_upgrade, verify that the install user has the same oid on both
clusters, and make sure the new cluster has no additional users.

Backpatch to 9.1.
In pg_upgrade, report pre-PG 8.1 plpython helper functions left in the
public schema that no longer point to valid shared object libraries, and
suggest a solution.

Backpatch to 9.1 (already in head)
Add missing subtitle for compressed archive logs
Update copyright year in forgotten places

found by Stefan Kaltenbrunner
pg_dump: Fix verbosity level in LO progress messages

In passing, reword another instance of the same message that was
gratuitously different.

Author: Josh Kupershmidt
after a bug report by Bosco Rama
Fix memory leak in ARRAY(SELECT ...) subqueries.

Repeated execution of an uncorrelated ARRAY_SUBLINK sub-select (which
I think can only happen if the sub-select is embedded in a larger,
correlated subquery) would leak memory for the duration of the query,
due to not reclaiming the array generated in the previous execution.
Per bug #6698 from Armando Miraglia.  Diagnosis and fix idea by Heikki,
patch itself by me.

This has been like this all along, so back-patch to all supported versions.
Improve pg_dump's dependency-sorting logic to enforce section dump order.

As of 9.2, with the --section option, it is very important that the concept
of "pre data", "data", and "post data" sections of the output be honored
strictly; else a dump divided into separate sectional files might be
unrestorable.  However, the dependency-sorting logic knew nothing of
sections and would happily select output orderings that didn't fit that
structure.  Doing so was mostly harmless before 9.2, but now we need to be
sure it doesn't do that.  To fix, create dummy objects representing the
section boundaries and add dependencies between them and all the normal
objects.  (This might sound expensive but it seems to only add a percent or
two to pg_dump's runtime.)

This also fixes a problem introduced in 9.1 by the feature that allows
incomplete GROUP BY lists when a primary key is given in GROUP BY.
That means that views can depend on primary key constraints.  Previously,
pg_dump would deal with that by simply emitting the primary key constraint
before the view definition (and hence before the data section of the
output).  That's bad enough for simple serial restores, where creating an
index before the data is loaded works, but is undesirable for speed
reasons.  But it could lead to outright failure of parallel restores, as
seen in bug #6699 from Joe Van Dyk.  That happened because pg_restore would
switch into parallel mode as soon as it reached the constraint, and then
very possibly would try to emit the view definition before the primary key
was committed (as a consequence of another bug that causes the view not to
be correctly marked as depending on the constraint).  Adding the section
boundary constraints forces the dependency-sorting code to break the view
into separate table and rule declarations, allowing the rule, and hence the
primary key constraint it depends on, to revert to their intended location
in the post-data section.  This also somewhat accidentally works around the
bogus-dependency-marking problem, because the rule will be correctly shown
as depending on the constraint, so parallel pg_restore will now do the
right thing.  (We will fix the bogus-dependency problem for real in a
separate patch, but that patch is not easily back-portable to 9.1, so the
fact that this patch is enough to dodge the only known symptom is
fortunate.)

Back-patch to 9.1, except for the hunk that adds verification that the
finished archive TOC list is in correct section order; the place where
it was convenient to add that doesn't exist in 9.1.
Fix NOTIFY to cope with I/O problems, such as out-of-disk-space.

The LISTEN/NOTIFY subsystem got confused if SimpleLruZeroPage failed,
which would typically happen as a result of a write() failure while
attempting to dump a dirty pg_notify page out of memory.  Subsequently,
all attempts to send more NOTIFY messages would fail with messages like
"Could not read from file "pg_notify/nnnn" at offset nnnnn: Success".
Only restarting the server would clear this condition.  Per reports from
Kevin Grittner and Christoph Berg.

Back-patch to 9.0, where the problem was introduced during the
LISTEN/NOTIFY rewrite.
Initialize shared memory copy of ckptXidEpoch correctly when not in recovery.

This bug was introduced by commit 20d98ab6e4110087d1816cd105a40fcc8ce0a307,
so backpatch this to 9.0-9.2 like that one.

This fixes bug #6710, reported by Tarvi Pillessaar
Prevent CREATE TABLE LIKE/INHERITS from (mis) copying whole-row Vars.

If a CHECK constraint or index definition contained a whole-row Var (that
is, "table.*"), an attempt to copy that definition via CREATE TABLE LIKE or
table inheritance produced incorrect results: the copied Var still claimed
to have the rowtype of the source table, rather than the created table.

For the LIKE case, it seems reasonable to just throw error for this
situation, since the point of LIKE is that the new table is not permanently
coupled to the old, so there's no reason to assume its rowtype will stay
compatible.  In the inheritance case, we should ideally allow such
constraints, but doing so will require nontrivial refactoring of CREATE
TABLE processing (because we'd need to know the OID of the new table's
rowtype before we adjust inherited CHECK constraints).  In view of the lack
of previous complaints, that doesn't seem worth the risk in a back-patched
bug fix, so just make it throw error for the inheritance case as well.

Along the way, replace change_varattnos_of_a_node() with a more robust
function map_variable_attnos(), which is capable of being extended to
handle insertion of ConvertRowtypeExpr whenever we get around to fixing
the inheritance case nicely, and in the meantime it returns a failure
indication to the caller so that a helpful message with some context can be
thrown.  Also, this code will do the right thing with subselects (if we
ever allow them in CHECK or indexes), and it range-checks varattnos before
using them to index into the map array.

Per report from Sergey Konoplev.  Back-patch to all supported branches.
Fix race condition in enum value comparisons.

When (re) loading the typcache comparison cache for an enum type's values,
use an up-to-date MVCC snapshot, not the transaction's existing snapshot.
This avoids problems if we encounter an enum OID that was created since our
transaction started.  Per report from Andres Freund and diagnosis by Robert
Haas.

To ensure this is safe even if enum comparison manages to get invoked
before we've set a transaction snapshot, tweak GetLatestSnapshot to
redirect to GetTransactionSnapshot instead of throwing error when
FirstSnapshotSet is false.  The existing uses of GetLatestSnapshot (in
ri_triggers.c) don't care since they couldn't be invoked except in a
transaction that's already done some work --- but it seems just conceivable
that this might not be true of enums, especially if we ever choose to use
enums in system catalogs.

Note that the comparable coding in enum_endpoint and enum_range_internal
remains GetTransactionSnapshot; this is perhaps debatable, but if we
changed it those functions would have to be marked volatile, which doesn't
seem attractive.

Back-patch to 9.1 where ALTER TYPE ADD VALUE was added.
Have REASSIGN OWNED work on extensions, too

Per bug #6593, REASSIGN OWNED fails when the affected role has created
an extension.  Even though the user related to the extension is not
nominally the owner, its OID appears on pg_shdepend and thus causes
problems when the user is to be dropped.

This commit adds code to change the "ownership" of the extension itself,
not of the contained objects.  This is fine because it's currently only
called from REASSIGN OWNED, which would also modify the ownership of the
contained objects.  However, this is not sufficient for a working ALTER
OWNER implementation extension.

Back-patch to 9.1, where extensions were introduced.

Bug #6593 reported by Emiliano Leporati.
Forgot an #include in the previous patch :-(
Remove references to pgfoundry as recommended hosting platform

pgfoundry is deprectaed and no longer accepting new projects,
so we really shouldn't be directing people there.
Remove references to PostgreSQL bundled on Solaris

Also remove special references to downloads off pgfoundry since they are
not correct - downloads are done through the main website.