Fix plpgsql's reporting of plan-time errors in possibly-simple expressions.

exec_simple_check_plan and exec_eval_simple_expr attempted to call
GetCachedPlan directly.  This meant that if an error was thrown during
planning, the resulting context traceback would not include the line
normally contributed by _SPI_error_callback.  This is already inconsistent,
but just to be really odd, a re-execution of the very same expression
*would* show the additional context line, because we'd already have cached
the plan and marked the expression as non-simple.

The problem is easy to demonstrate in 9.2 and HEAD because planning of a
cached plan doesn't occur at all until GetCachedPlan is done.  In earlier
versions, it could only be an issue if initial planning had succeeded, then
a replan was forced (already somewhat improbable for a simple expression),
and the replan attempt failed.  Since the issue is mainly cosmetic in older
branches anyway, it doesn't seem worth the risk of trying to fix it there.
It is worth fixing in 9.2 since the instability of the context printout can
affect the results of GET STACKED DIAGNOSTICS, as per a recent discussion
on pgsql-novice.

To fix, introduce a SPI function that wraps GetCachedPlan while installing
the correct callback function.  Use this instead of calling GetCachedPlan
directly from plpgsql.

Also introduce a wrapper function for extracting a SPI plan's
CachedPlanSource list.  This lets us stop including spi_priv.h in
pl_exec.c, which was never a very good idea from a modularity standpoint.

In passing, fix a similar inconsistency that could occur in SPI_cursor_open,
which was also calling GetCachedPlan without setting up a context callback.
Don't use spi_priv.h in plpython.

There may once have been a reason to violate modularity like that,
but it doesn't appear that there is anymore.
Add --aggregate-interval option.

The new option specifies length of aggregation interval (in
seconds). May be used only together with -l. With this option, the log
contains per-interval summary (number of transactions, min/max latency
and two additional fields useful for variance estimation).

Patch contributed by Tomas Vondra, reviewed by Pavel Stehule. Slight
change by Tatsuo Ishii, suggested by Robert Hass to emit an error
message indicating that the option is not currently supported on
Windows.
Properly zero-pad the day-of-year part of the win32 build number

This ensure the version number increases over time. The first three digits
in the version number is still set to the actual PostgreSQL version
number, but the last one is intended to be an ever increasing build number,
which previosly failed when it changed between 1, 2 and 3 digits long values.

Noted by Deepak
Reject nonzero day fields in AT TIME ZONE INTERVAL functions.

It's not sensible for an interval that's used as a time zone value to be
larger than a day.  When we changed the interval type to contain a separate
day field, check_timezone() was adjusted to reject nonzero day values, but
timetz_izone(), timestamp_izone(), and timestamptz_izone() evidently were
overlooked.

While at it, make the error messages for these three cases consistent.
Switch timelines if we crash soon after promotion.
Previous patch to skip checkpoints at end of recovery didn't
correctly perform crash recovery, fumbling the timeline switch.
Now we record the minRecoveryPointTLI of the newly selected
timeline, so that we crash recover to the correct timeline.

Bug report from Fujii Masao, investigated by me.
pg_upgrade docs: mention modification of postgresql.conf in new cluster

Mention it might be necessary to modify postgresql.conf in the new
cluster to match the old cluster.

Backpatch to 9.2.

Suggested by user.
pgrowlocks: fix bogus lock strength output

Per report from digoal@126.com
Restrict infomask bits to set on multixacts

We must only set the bit(s) for the strongest lock held in the tuple;
otherwise, a multixact containing members with exclusive lock and
key-share lock will behave as though only a share lock is held.

This bug was introduced in commit 0ac5ad5134, somewhere along
development, when we allowed a singleton FOR SHARE lock to be
implemented without a MultiXact by using a multi-bit pattern.
I overlooked that GetMultiXactIdHintBits() needed to be tweaked as well.
Previously, we could have the bits for FOR KEY SHARE and FOR UPDATE
simultaneously set and it wouldn't cause a problem.

Per report from digoal@126.com
PL/Tcl: Fix compiler warnings with Tcl 8.6

Some constification was added in the Tcl APIs, so add the modifiers in
PL/Tcl as well.
Add CREATE RECURSIVE VIEW syntax

This is specified in the SQL standard.  The CREATE RECURSIVE VIEW
specification is transformed into a normal CREATE VIEW statement with a
WITH RECURSIVE clause.

reviewed by Abhijit Menon-Sen and Stephen Frost
Fill tuple before HeapSatisfiesHOTAndKeyUpdate

Failing to do this results in almost all updates to system catalogs
being non-HOT updates, because the OID column would differ (not having
been set for the new tuple), which is an indexed column.

While at it, make sure to set the tableoid early in both old and new
tuples as well.  This isn't of much consequence, since that column is
seldom (never?) indexed.

Report and patch from Andres Freund.
Fix typo in freeze_table_age implementation

The original code used freeze_min_age instead of freeze_table_age.  The
main consequence of this mistake is that lowering freeze_min_age would
cause full-table scans to occur much more frequently, which causes
serious issues because the number of writes required is much larger.
That feature (freeze_min_age) is supposed to affect only how soon tuples
are frozen; some pages should still be skipped due to the visibility
map.

Backpatch to 8.4, where the freeze_table_age feature was introduced.

Report and patch from Andres Freund
Move Assert() definitions to c.h

This way, they can be used by frontend and backend code.  We already
supported that, but doing it this way allows us to mix true frontend
files with backend files compiled in frontend environment.

Author: Andres Freund
doc: Tiny whitespace fix
Adjust COPY FREEZE error message to be more accurate and consistent.

Per suggestions from Noah and Tom.
Mark vacuum_defer_cleanup_age as PGC_POSTMASTER.

Following bug analysis of #7819 by Tom Lane
Prevent "\g filename" from affecting subsequent commands after an error.

In the previous coding, psql's state variable saying that output should
go to a file was only reset after successful completion of a query
returning tuples.  Thus for example,

regression=# select 1/0
regression-# \g somefile
ERROR:  division by zero
regression=# select 1/2;
regression=#

... huh, I wonder where that output went.  Even more oddly, the state
was not reset even if it's the file that's causing the failure:

regression=# select 1/2 \g /foo
/foo: Permission denied
regression=# select 1/2;
/foo: Permission denied
regression=# select 1/2;
/foo: Permission denied

This seems to me not to satisfy the principle of least surprise.
\g is certainly not documented in a way that suggests its effects are
at all persistent.

To fix, adjust the code so that the flag is reset at exit from SendQuery
no matter what happened.

Noted while reviewing the \gset patch, which had comparable issues.
Arguably this is a bug fix, but I'll refrain from back-patching for now.
Create a psql command \gset to store query results into psql variables.

This eases manipulation of query results in psql scripts.

Pavel Stehule, reviewed by Piyush Newe, Shigeru Hanada, and Tom Lane
PL/Python: Add result object str handler

This is intended so that say plpy.debug(rv) prints something useful for
debugging query execution results.

reviewed by Steve Singer