Improve connectMaintenanceDatabase() error reporting.

The prior coding instructs the user to pick an alternative maintenance
database, but this is overly clever, since it obscures whatever the real
cause of the failure is.

Josh Kupershmidt
Allow new relmapper entries when allow_system_table_mods is true.

This restores the pre-9.0 situation that it's possible to add new indexes
on pg_class and other mapped-but-not-shared catalogs, so long as you broke
the glass and flipped the big red Dont-Touch-Me switch.  As before, there
are a lot of gotchas, and you'd have to be pretty desperate to try this
on a production database; but there doesn't seem to be a reason for
relmapper.c to be preventing such things all by itself.  Per
experimentation with a case suggested by Cody Cutrer.
Doc updates for index-only scans.

Document that routine vacuuming is now also important for the purpose
of index-only scans; and mention in the section that describes the
visibility map that it is used to implement index-only scans.

Marti Raudsepp, with some changes by me.
Add installing entab to pgindent instructions

And minor other pgindent documentation tweaks.
Clean up compiler warnings from unused variables with asserts disabled

For those variables only used when asserts are enabled, use a new
macro PG_USED_FOR_ASSERTS_ONLY, which expands to
__attribute__((unused)) when asserts are not enabled.
Fix configure's search for collateindex.pl.

PGAC_PATH_COLLATEINDEX supposed that it could use AC_PATH_PROGS to search
for collateindex.pl, but that macro will only accept files that are marked
executable, and at least some DocBook installations don't mark the script
executable (a case the docs Makefile was already prepared for).  Accept the
script if it's present and readable in $DOCBOOKSTYLE/bin, and otherwise
search the PATH as before.

Having fixed that up, we don't need the fallback case that was in the docs
Makefile, and instead can throw an understandable error if configure didn't
find the script.  Per recent trouble report from John Lumby.
If a role has a password expiration date, show that in psql's \du output.

Per a suggestion from Euler Taveira, it seems like a good idea to include
this information in \du (and \dg) output.  This costs nothing for people
who are not using the VALID UNTIL feature, while for those who are, it's
rather critical information.

Fabrízio de Royes Mello
Refactor to eliminate duplicate copies of conninfo default-finding code.

Alex Shulgin, lightly edited by me
Fix GET DIAGNOSTICS for case of assignment to function's first variable.

An incorrect and entirely unnecessary "safety check" in exec_stmt_getdiag()
caused the code to treat an assignment to a variable with dno zero as a
no-op.  Unfortunately, that's a perfectly valid dno.  This has been broken
since GET DIAGNOSTICS was invented.  It's not terribly surprising that the
bug went unnoticed for so long, since in most cases you probably wouldn't
use the function's first-created variable (normally its first parameter)
as a GET DIAGNOSTICS target.  Nonetheless, it's broken.  Per bug #6551
from Adam Buraczewski.
Update docs on numeric storage requirements.

Since 9.1, the minimum overhead is three bytes, not five.

Fujii Masao
Doc clarifications regarding use of varlena.

Jay Levitt, reviewed by Tom Lane.
Clarify that PQconninfoParse returns an array with all legal options.

Per discussion with Dmitriy Igrishin and Tom Lane.
Code review for protransform patches.

Fix loss of previous expression-simplification work when a transform
function fires: we must not simply revert to untransformed input tree.
Instead build a dummy FuncExpr node to pass to the transform function.
This has the additional advantage of providing a simpler, more uniform
API for transform functions.

Move documentation to a somewhat less buried spot, relocate some
poorly-placed code, be more wary of null constants and invalid typmod
values, add an opr_sanity check on protransform function signatures,
and some other minor cosmetic adjustments.

Note: although this patch touches pg_proc.h, no need for catversion
bump, because the changes are cosmetic and don't actually change the
intended catalog contents.
Refactor simplify_function et al to centralize argument simplification.

We were doing the recursive simplification of function/operator arguments
in half a dozen different places, with rather baroque logic to ensure it
didn't get done multiple times on some arguments.  This patch improves that
by postponing argument simplification until after we've dealt with named
parameters and added any needed default expressions.

Marti Raudsepp, somewhat hacked on by me
Cast some printf arguments to avoid possibly-nonportable behavior.

Per compiler warnings on buildfarm member black_firefly.
Fix planner's handling of outer PlaceHolderVars within subqueries.

For some reason, in the original coding of the PlaceHolderVar mechanism
I had supposed that PlaceHolderVars couldn't propagate into subqueries.
That is of course entirely possible.  When it happens, we need to treat
an outer-level PlaceHolderVar much like an outer Var or Aggref, that is
SS_replace_correlation_vars() needs to replace the PlaceHolderVar with
a Param, and then when building the finished SubPlan we have to provide
the PlaceHolderVar expression as an actual parameter for the SubPlan.
The handling of the contained expression is a bit delicate but it can be
treated exactly like an Aggref's expression.

In addition to the missing logic in subselect.c, prepjointree.c was failing
to search subqueries for PlaceHolderVars that need their relids adjusted
during subquery pullup.  It looks like everyplace else that touches
PlaceHolderVars got it right, though.

Per report from Mark Murawski.  In 9.1 and HEAD, queries affected by this
oversight would fail with "ERROR: Upper-level PlaceHolderVar found where
not expected".  But in 9.0 and 8.4, you'd silently get possibly-wrong
answers, since the value transmitted into the subquery wouldn't go to null
when it should.
Replace empty locale name with implied value in CREATE DATABASE and initdb.

setlocale() accepts locale name "" as meaning "the locale specified by the
process's environment variables".  Historically we've accepted that for
Postgres' locale settings, too.  However, it's fairly unsafe to store an
empty string in a new database's pg_database.datcollate or datctype fields,
because then the interpretation could vary across postmaster restarts,
possibly resulting in index corruption and other unpleasantness.

Instead, we should expand "" to whatever it means at the moment of calling
CREATE DATABASE, which we can do by saving the value returned by
setlocale().

For consistency, make initdb set up the initial lc_xxx parameter values the
same way.  initdb was already doing the right thing for empty locale names,
but it did not replace non-empty names with setlocale results.  On a
platform where setlocale chooses to canonicalize the spellings of locale
names, this would result in annoying inconsistency.  (It seems that popular
implementations of setlocale don't do such canonicalization, which is a
pity, but the POSIX spec certainly allows it to be done.)  The same risk
of inconsistency leads me to not venture back-patching this, although it
could certainly be seen as a longstanding bug.

Per report from Jeff Davis, though this is not his proposed patch.
Fix COPY FROM for null marker strings that correspond to invalid encoding.

The COPY documentation says "COPY FROM matches the input against the null
string before removing backslashes".  It is therefore reasonable to presume
that null markers like E'\\0' will work ... and they did, until someone put
the tests in the wrong order during microoptimization-driven rewrites.
Since then, we've been failing if the null marker is something that would
de-escape to an invalidly-encoded string.  Since null markers generally
need to be something that can't appear in the data, this represents a
nontrivial loss of functionality; surprising nobody noticed it earlier.

Per report from Jeff Davis.  Backpatch to 8.4 where this got broken.
Code cleanup for heap_freeze_tuple.

It used to be case that lazy vacuum could call this function with only
a shared lock on the buffer, but neither lazy vacuum nor any other
code path does that any more.  Simplify the code accordingly and clean
up some related, obsolete comments.
Remove dead assignment

found by Coverity