Commit Graph

36848 Commits

Author SHA1 Message Date
Andres Freund
a6d488cb53 Remove Alpha and Tru64 support.
Support for running postgres on Alpha hasn't been tested for a long
while. Due to Alpha's uniquely lax cache coherency model it's a hard
to develop for platform (especially blindly!) and thought to be
unlikely to currently work correctly.

As Alpha is the only supported architecture for Tru64 drop support for
it as well. Tru64's support has ended 2012 and it has been in
maintenance-only mode for much longer.

Also remove stray references to __ksr__ and ultrix defines.
2014-06-28 21:46:15 +02:00
Tom Lane
d222585a9f Allow pushdown of WHERE quals into subqueries with window functions.
We can allow this even without any specific knowledge of the semantics
of the window function, so long as pushed-down quals will either accept
every row in a given window partition, or reject every such row.  Because
window functions act only within a partition, such a case can't result
in changing the window functions' outputs for any surviving row.
Eliminating entire partitions in this way obviously can reduce the cost
of the window-function computations substantially.

The fly in the ointment is that it's hard to be entirely sure whether
this is true for an arbitrary qual condition.  This patch allows pushdown
if (a) the qual references only partitioning columns, and (b) the qual
contains no volatile functions.  We are at risk of incorrect results if
the qual can produce different answers for values that the partitioning
equality operator sees as equal.  While it's not hard to invent cases
for which that can happen, it seems to seldom be a problem in practice,
since no one has complained about a similar assumption that we've had
for many years with respect to DISTINCT.  The potential performance
gains seem to be worth the risk.

David Rowley, reviewed by Vik Fearing; some credit is due also to
Thomas Mayer who did considerable preliminary investigation.
2014-06-27 23:08:08 -07:00
Alvaro Herrera
f741300c90 Have multixact be truncated by checkpoint, not vacuum
Instead of truncating pg_multixact at vacuum time, do it only at
checkpoint time.  The reason for doing it this way is twofold: first, we
want it to delete only segments that we're certain will not be required
if there's a crash immediately after the removal; and second, we want to
do it relatively often so that older files are not left behind if
there's an untimely crash.

Per my proposal in
http://www.postgresql.org/message-id/20140626044519.GJ7340@eldon.alvh.no-ip.org
we now execute the truncation in the checkpointer process rather than as
part of vacuum.  Vacuum is in only charge of maintaining in shared
memory the value to which it's possible to truncate the files; that
value is stored as part of checkpoints also, and so upon recovery we can
reuse the same value to re-execute truncate and reset the
oldest-value-still-safe-to-use to one known to remain after truncation.

Per bug reported by Jeff Janes in the course of his tests involving
bug #8673.

While at it, update some comments that hadn't been updated since
multixacts were changed.

Backpatch to 9.3, where persistency of pg_multixact files was
introduced by commit 0ac5ad5134.
2014-06-27 14:43:53 -04:00
Alvaro Herrera
b7e51d9c06 Don't allow relminmxid to go backwards during VACUUM FULL
We were allowing a table's pg_class.relminmxid value to move backwards
when heaps were swapped by VACUUM FULL or CLUSTER.  There is a
similar protection against relfrozenxid going backwards, which we
neglected to clone when the multixact stuff was rejiggered by commit
0ac5ad5134.

Backpatch to 9.3, where relminmxid was introduced.

As reported by Heikki in
http://www.postgresql.org/message-id/52401AEA.9000608@vmware.com
2014-06-27 14:43:46 -04:00
Alvaro Herrera
b277057648 Fix broken Assert() introduced by 8e9a16ab8f
Don't assert MultiXactIdIsRunning if the multi came from a tuple that
had been share-locked and later copied over to the new cluster by
pg_upgrade.  Doing that causes an error to be raised unnecessarily:
MultiXactIdIsRunning is not open to the possibility that its argument
came from a pg_upgraded tuple, and all its other callers are already
checking; but such multis cannot, obviously, have transactions still
running, so the assert is pointless.

Noticed while investigating the bogus pg_multixact/offsets/0000 file
left over by pg_upgrade, as reported by Andres Freund in
http://www.postgresql.org/message-id/20140530121631.GE25431@alap3.anarazel.de

Backpatch to 9.3, as the commit that introduced the buglet.
2014-06-27 14:43:39 -04:00
Tom Lane
1147035203 Disallow pushing volatile qual expressions down into DISTINCT subqueries.
A WHERE clause applied to the output of a subquery with DISTINCT should
theoretically be applied only once per distinct row; but if we push it
into the subquery then it will be evaluated at each row before duplicate
elimination occurs.  If the qual is volatile this can give rise to
observably wrong results, so don't do that.

While at it, refactor a little bit to allow subquery_is_pushdown_safe
to report more than one kind of restrictive condition without indefinitely
expanding its argument list.

Although this is a bug fix, it seems unwise to back-patch it into released
branches, since it might de-optimize plans for queries that aren't giving
any trouble in practice.  So apply to 9.4 but not further back.
2014-06-27 11:08:48 -07:00
Tom Lane
f71136eeeb Get rid of bogus separate pg_proc entries for json_extract_path operators.
These should not have existed to begin with, but there was apparently some
misunderstanding of the purpose of the opr_sanity regression test item
that checks for operator implementation functions with their own comments.
The idea there is to check for unintentional violations of the rule that
operator implementation functions shouldn't be documented separately
.... but for these functions, that is in fact what we want, since the
variadic option is useful and not accessible via the operator syntax.
Get rid of the extra pg_proc entries and fix the regression test and
documentation to be explicit about what we're doing here.
2014-06-26 16:22:15 -07:00
Tom Lane
344eed91e9 Forward-patch regression test for "could not find pathkey item to sort".
Commit a87c729153 already fixed the bug this
is checking for, but the regression test case it added didn't cover this
scenario.  Since we managed to miss the fact that there was a bug at all,
it seems like a good idea to propagate the extra test case forward to HEAD.
2014-06-26 10:41:48 -07:00
Fujii Masao
de42ed401a Remove obsolete example of CSV log file name from log_filename document.
7380b63 changed log_filename so that epoch was not appended to it
when no format specifier is given. But the example of CSV log file name
with epoch still left in log_filename document. This commit removes
such obsolete example.

This commit also documents the defaults of log_directory and
log_filename.

Backpatch to all supported versions.

Christoph Berg
2014-06-26 14:27:27 +09:00
Tom Lane
798e235790 Rationalize error messages within jsonfuncs.c.
I noticed that the functions in jsonfuncs.c sometimes printed error
messages that claimed I'd called some other function.  Investigation showed
that this was from repurposing code into "worker" functions without taking
much care as to whether it would mention the right SQL-level function if it
threw an error.  Moreover, there was a weird mismash of messages that
contained a fixed function name, messages that used %s for a function name,
and messages that constructed a function name out of spare parts, like
"json%s_populate_record" (which, quite aside from being ugly as sin, wasn't
even sufficient to cover all the cases).  This would put an undue burden on
our long-suffering translators.  Standardize on inserting the SQL function
name with %s so as to reduce the number of translatable strings, and pass
function names around as needed to make sure we can report the right one.
Fix up some gratuitous variations in wording, too.
2014-06-25 15:25:22 -07:00
Tom Lane
8d2d7ad5ab Cosmetic improvements in jsonfuncs.c.
Re-pgindent, remove a lot of random vertical whitespace, remove useless
(if not counterproductive) inline markings, get rid of unnecessary
zero-padding of strings for hashtable searches.  No functional changes.
2014-06-25 11:22:18 -07:00
Tom Lane
57d8c1270e Fix handling of nested JSON objects in json_populate_recordset and friends.
populate_recordset_object_start() improperly created a new hash table
(overwriting the link to the existing one) if called at nest levels
greater than one.  This resulted in previous fields not appearing in
the final output, as reported by Matti Hameister in bug #10728.
In 9.4 the problem also affects json_to_recordset.

This perhaps missed detection earlier because the default behavior is to
throw an error for nested objects: you have to pass use_json_as_text = true
to see the problem.

In addition, fix query-lifespan leakage of the hashtable created by
json_populate_record().  This is pretty much the same problem recently
fixed in dblink: creating an intended-to-be-temporary context underneath
the executor's per-tuple context isn't enough to make it go away at the
end of the tuple cycle, because MemoryContextReset is not
MemoryContextResetAndDeleteChildren.

Michael Paquier and Tom Lane
2014-06-24 21:22:40 -07:00
Bruce Momjian
0f7482733a pg_upgrade: remove pg_multixact files left by initdb
This fixes a bug that caused vacuum to fail when the '0000' files left
by initdb were accessed as part of vacuum's cleanup of old pg_multixact
files.

Backpatch through 9.3
2014-06-24 16:11:06 -04:00
Heikki Linnakangas
a87a7dc8b6 Don't allow foreign tables with OIDs.
The syntax doesn't let you specify "WITH OIDS" for foreign tables, but it
was still possible with default_with_oids=true. But the rest of the system,
including pg_dump, isn't prepared to handle foreign tables with OIDs
properly.

Backpatch down to 9.1, where foreign tables were introduced. It's possible
that there are databases out there that already have foreign tables with
OIDs. There isn't much we can do about that, but at least we can prevent
them from being created in the future.

Patch by Etsuro Fujita, reviewed by Hadi Moshayedi.
2014-06-24 13:27:18 +03:00
Robert Haas
c922353b1c Check for interrupts during tuple-insertion loops.
Normally, this won't matter too much; but if I/O is really slow, for
example because the system is overloaded, we might write many pages
before checking for interrupts.  A single toast insertion might
write up to 1GB of data, and a multi-insert could write hundreds
of tuples (and their corresponding TOAST data).
2014-06-23 21:45:21 -04:00
Heikki Linnakangas
631e7f6b4e Improve tab-completion of DROP and ALTER ENABLE/DISABLE on triggers and rules.
At "DROP RULE/TRIGGER triggername ON ...", tab-complete tables that have
a rule/trigger with that name.

At "ALTER TABLE tablename ENABLE/DISABLE TRIGGER/RULE ...", tab-complete to
rules/triggers on that table. Previously, we would tab-complete to all
rules or triggers, not just those that are on that table.

Also, filter out internal RI triggers from the list. You can't DROP them,
and enabling/disabling them is such a rare (and dangerous) operation that
it seems better to hide them.

Andreas Karlsson, reviewed by Ian Barwick.
2014-06-23 23:56:20 +03:00
Fujii Masao
f8ad8bd473 Fix typo in replication slot function doc. 2014-06-24 03:51:51 +09:00
Fujii Masao
394e05996f Add missing closing parenthesis into max_replication_slots doc. 2014-06-24 03:25:01 +09:00
Heikki Linnakangas
85ba0748ed Fix bug in WAL_DEBUG.
The record header was not copied correctly to the buffer that was passed
to the rm_desc function. Broken by my rm_desc signature refactoring patch.
2014-06-23 12:22:36 +03:00
Bruce Momjian
884dede37a doc: adjust JSONB GIN index description
Backpatch through 9.4
2014-06-21 15:33:23 -04:00
Bruce Momjian
a52f2a0b9c 9.4 release notes: adjust some entry wording
Backpatch to 9.4
2014-06-21 10:57:23 -04:00
Kevin Grittner
734bea8a69 Fix documentation template for CREATE TRIGGER.
By using curly braces, the template had specified that one of
"NOT DEFERRABLE", "INITIALLY IMMEDIATE", or "INITIALLY DEFERRED"
was required on any CREATE TRIGGER statement, which is not
accurate.  Change to square brackets makes that optional.

Backpatch to 9.1, where the error was introduced.
2014-06-21 09:17:04 -05:00
Tom Lane
8b38a538c0 Add Asserts to verify that catalog cache keys are unique and not null.
The catcache code is effectively assuming this already, so let's insist
that the catalog and index are actually declared that way.

Having done that, the comments in indexing.h about non-unique indexes
not being used for catcaches are completely redundant not just mostly so;
and we didn't have such a comment for every such index anyway.  So let's
get rid of them.

Per discussion of whether we should identify primary keys for catalogs.
We might or might not take that further step, but this change in itself
will allow quicker detection of misdeclared catcaches, so it seems worth
doing in any case.
2014-06-20 18:21:05 -04:00
Joe Conway
1dde5782e3 Clean up data conversion short-lived memory context.
dblink uses a short-lived data conversion memory context. However it
was not deleted when no longer needed, leading to a noticeable memory
leak under some circumstances. Plug the hole, along with minor
refactoring. Backpatch to 9.2 where the leak was introduced.

Report and initial patch by MauMau. Reviewed/modified slightly by
Tom Lane and me.
2014-06-20 12:24:59 -07:00
Andres Freund
ecac0e2b9e Do all-visible handling in lazy_vacuum_page() outside its critical section.
Since fdf9e21196 lazy_vacuum_page() rechecks the all-visible status
of pages in the second pass over the heap. It does so inside a
critical section, but both visibilitymap_test() and
heap_page_is_all_visible() perform operations that should not happen
inside one. The former potentially performs IO and both potentially do
memory allocations.

To fix, simply move all the all-visible handling outside the critical
section. Doing so means that the PD_ALL_VISIBLE on the page won't be
included in the full page image of the HEAP2_CLEAN record anymore. But
that's fine, the flag will be set by the HEAP2_VISIBLE logged later.

Backpatch to 9.3 where the problem was introduced. The bug only came
to light due to the assertion added in 4a170ee9 and isn't likely to
cause problems in production scenarios. The worst outcome is a
avoidable PANIC restart.

This also gets rid of the difference in the order of operations
between master and standby mentioned in 2a8e1ac5.

Per reports from David Leverton and Keith Fiske in bug #10533.
2014-06-20 11:09:17 +02:00
Andres Freund
3bdcf6a5a7 Don't allow to disable backend assertions via the debug_assertions GUC.
The existance of the assert_enabled variable (backing the
debug_assertions GUC) reduced the amount of knowledge some static code
checkers (like coverity and various compilers) could infer from the
existance of the assertion. That could have been solved by optionally
removing the assertion_enabled variable from the Assert() et al macros
at compile time when some special macro is defined, but the resulting
complication doesn't seem to be worth the gain from having
debug_assertions. Recompiling is fast enough.

The debug_assertions GUC is still available, but readonly, as it's
useful when diagnosing problems. The commandline/client startup option
-A, which previously also allowed to enable/disable assertions, has
been removed as it doesn't serve a purpose anymore.

While at it, reduce code duplication in bufmgr.c and localbuf.c
assertions checking for spurious buffer pins. That code had to be
reindented anyway to cope with the assert_enabled removal.
2014-06-20 11:09:17 +02:00
Tom Lane
45b0f35723 Avoid leaking memory while evaluating arguments for a table function.
ExecMakeTableFunctionResult evaluated the arguments for a function-in-FROM
in the query-lifespan memory context.  This is insignificant in simple
cases where the function relation is scanned only once; but if the function
is in a sub-SELECT or is on the inside of a nested loop, any memory
consumed during argument evaluation can add up quickly.  (The potential for
trouble here had been foreseen long ago, per existing comments; but we'd
not previously seen a complaint from the field about it.)  To fix, create
an additional temporary context just for this purpose.

Per an example from MauMau.  Back-patch to all active branches.
2014-06-19 22:14:26 -04:00
Noah Misch
686f362bee Fix contrib/pg_upgrade/test.sh for $PWD containing spaces.
Most of the necessary quoting was in place; this catches the exceptions.
2014-06-19 21:47:08 -04:00
Noah Misch
c82725edfa Let installcheck-world pass against a server requiring a password.
Give passwords to each user created in support of an ECPG connection
test case.  Use SET SESSION AUTHORIZATION, not a fresh connection, to
reduce privileges during a dblink test case.

To test against such a server, both the "make installcheck-world"
environment and the postmaster environment must provide the default
user's password; $PGPASSFILE is the principal way to do so.  (The
postmaster environment needs it for dblink and postgres_fdw tests.)
2014-06-19 21:41:26 -04:00
Tom Lane
f28d9b10f7 Document SQL functions' behavior of parsing the whole function at once.
Haribabu Kommi, somewhat rewritten by me
2014-06-19 12:33:56 -04:00
Kevin Grittner
bfaa8c665f Fix calculation of PREDICATELOCK_MANAGER_LWLOCK_OFFSET.
Commit ea9df812d8 failed to include
NUM_BUFFER_PARTITIONS in this offset, resulting in a bad offset.
Ultimately this threw off NUM_FIXED_LWLOCKS which is based on
earlier offsets, leading to memory allocation problems.  It seems
likely to have also caused increased LWLOCK contention when
serializable transactions were used, because lightweight locks used
for that overlapped others.

Reported by Amit Kapila with analysis and fix.
Backpatch to 9.4, where the bug was introduced.
2014-06-19 08:40:37 -05:00
Fujii Masao
9ba78fb0b9 Don't allow data_directory to be set in postgresql.auto.conf by ALTER SYSTEM.
data_directory could be set both in postgresql.conf and postgresql.auto.conf so far.
This could cause some problematic situations like circular definition. To avoid such
situations, this commit forbids a user to set data_directory in postgresql.auto.conf.

Backpatch this to 9.4 where ALTER SYSTEM command was introduced.

Amit Kapila, reviewed by Abhijit Menon-Sen, with minor adjustments by me.
2014-06-19 20:31:20 +09:00
Tom Lane
df8b7bc9ff Improve our mechanism for controlling the Linux out-of-memory killer.
Arrange for postmaster child processes to respond to two environment
variables, PG_OOM_ADJUST_FILE and PG_OOM_ADJUST_VALUE, to determine whether
they reset their OOM score adjustments and if so to what.  This is superior
to the previous design involving #ifdef's in several ways.  The behavior is
now available in a default build, and both ends of the adjustment --- the
original adjustment of the postmaster's level and the subsequent
readjustment by child processes --- can now be controlled in one place,
namely the postmaster launch script.  So it's no longer necessary for the
launch script to act on faith that the server was compiled with the
appropriate options.  In addition, if someone wants to use an OOM score
other than zero for the child processes, that doesn't take a recompile
anymore; and we no longer have to cater separately to the two different
historical kernel APIs for this adjustment.

Gurjeet Singh, somewhat revised by me
2014-06-18 20:12:51 -04:00
Andrew Dunstan
960661980b Remove unnecessary check for jbvBinary in convertJsonbValue.
The check was confusing and is a condition that should never in fact
happen.

Per gripe from Dmitry Dolgov.
2014-06-18 19:28:20 -04:00
Tom Lane
66802246e2 Fix weird spacing in error message.
Seems to have been introduced in 1a3458b6d8.
2014-06-18 15:44:35 -04:00
Andrew Dunstan
d2a986b74a Document that jsonb has all the standard comparison operators. 2014-06-18 15:18:22 -04:00
Tom Lane
8f889b1083 Implement UPDATE tab SET (col1,col2,...) = (SELECT ...), ...
This SQL-standard feature allows a sub-SELECT yielding multiple columns
(but only one row) to be used to compute the new values of several columns
to be updated.  While the same results can be had with an independent
sub-SELECT per column, such a workaround can require a great deal of
duplicated computation.

The standard actually says that the source for a multi-column assignment
could be any row-valued expression.  The implementation used here is
tightly tied to our existing sub-SELECT support and can't handle other
cases; the Bison grammar would have some issues with them too.  However,
I don't feel too bad about this since other cases can be converted into
sub-SELECTs.  For instance, "SET (a,b,c) = row_valued_function(x)" could
be written "SET (a,b,c) = (SELECT * FROM row_valued_function(x))".
2014-06-18 13:22:34 -04:00
Noah Misch
230ba02d85 Fix the MSVC build process for uuid-ossp.
Catch up with commit b8cc8f94730610c0189aa82dfec4ae6ce9b13e34's
introduction of the HAVE_UUID_OSSP symbol to the principal build
process.  Back-patch to 9.4, where that commit appeared.
2014-06-18 09:21:50 -04:00
Bruce Momjian
4cd3b1cbbd 9.4 release notes: improve valgrind mention
Report by Peter Geoghegan
2014-06-17 11:29:19 -04:00
Heikki Linnakangas
b29e715143 Revert accidental change of WAL_DEBUG default.
Oops.
2014-06-17 08:52:41 +03:00
Tom Lane
2146f13408 Avoid recursion when processing simple lists of AND'ed or OR'ed clauses.
Since most of the system thinks AND and OR are N-argument expressions
anyway, let's have the grammar generate a representation of that form when
dealing with input like "x AND y AND z AND ...", rather than generating
a deeply-nested binary tree that just has to be flattened later by the
planner.  This avoids stack overflow in parse analysis when dealing with
queries having more than a few thousand such clauses; and in any case it
removes some rather unsightly inconsistencies, since some parts of parse
analysis were generating N-argument ANDs/ORs already.

It's still possible to get a stack overflow with weirdly parenthesized
input, such as "x AND (y AND (z AND ( ... )))", but such cases are not
mainstream usage.  The maximum depth of parenthesization is already
limited by Bison's stack in such cases, anyway, so that the limit is
probably fairly platform-independent.

Patch originally by Gurjeet Singh, heavily revised by me
2014-06-16 15:55:30 -04:00
Bruce Momjian
ac608fe758 Use type pgsocket for Windows pipe emulation socket calls
This prevents several compiler warnings on Windows.
2014-06-16 15:24:38 -04:00
Noah Misch
be76a6d39e Secure Unix-domain sockets of "make check" temporary clusters.
Any OS user able to access the socket can connect as the bootstrap
superuser and proceed to execute arbitrary code as the OS user running
the test.  Protect against that by placing the socket in a temporary,
mode-0700 subdirectory of /tmp.  The pg_regress-based test suites and
the pg_upgrade test suite were vulnerable; the $(prove_check)-based test
suites were already secure.  Back-patch to 8.4 (all supported versions).
The hazard remains wherever the temporary cluster accepts TCP
connections, notably on Windows.

As a convenient side effect, this lets testing proceed smoothly in
builds that override DEFAULT_PGSOCKET_DIR.  Popular non-default values
like /var/run/postgresql are often unwritable to the build user.

Security: CVE-2014-0067
2014-06-14 09:41:13 -04:00
Noah Misch
9e6b1bf258 Add mkdtemp() to libpgport.
This function is pervasive on free software operating systems; import
NetBSD's implementation.  Back-patch to 8.4, like the commit that will
harness it.
2014-06-14 09:41:13 -04:00
Heikki Linnakangas
0ef0b6784c Change the signature of rm_desc so that it's passed a XLogRecord.
Just feels more natural, and is more consistent with rm_redo.
2014-06-14 10:46:48 +03:00
Noah Misch
f3fdd257a4 Harden pg_filenode_relation test against concurrent DROP TABLE.
Per buildfarm member prairiedog.  Back-patch to 9.4, where the test was
introduced.

Reviewed by Tom Lane.
2014-06-13 19:57:59 -04:00
Noah Misch
a7205d8157 Adjust 9.4 release notes.
Back-patch to 9.4.
2014-06-13 19:57:41 -04:00
Noah Misch
81300ea444 emacs.samples: Reliably override ".dir-locals.el".
Back-patch to 9.4, where .dir-locals.el was introduced.
2014-06-13 19:57:18 -04:00
Tom Lane
3f8c23c4d3 Improve predtest.c's ability to reason about operator expressions.
We have for a long time been able to prove implications and refutations
between clauses structured like "expr op const" with the same subexpression
and btree-related operators; for example that "x < 4" implies "x <= 5".
The implication machinery is needed to detect usability of partial indexes,
and the refutation machinery is needed to implement constraint exclusion.

This patch extends that machinery to make proofs for operator expressions
involving the same two immutable-but-not-necessarily-just-Const input
expressions, ie does "expr1 op1 expr2" prove or refute "expr1 op2 expr2" or
"expr2 op2 expr1"?  An important example is that we can now prove "x = y"
given "y = x", which formerly the code could not deduce unless x or y was a
constant.  We can make use of the system's knowledge of operator commutator
and negator pairs, and can also make use of btree opclass relationships,
for example "x < y" implies "x <= y" and refutes "x > y" (notice that
neither of these could be proven just from commutator or negator links).

Inspired by a gripe from Brian Dunavant.  This seems more like a new
feature than a bug fix, though, so no back-patch.
2014-06-13 00:02:56 -04:00
Tom Lane
c81e63d85f Fix pg_restore's processing of old-style BLOB COMMENTS data.
Prior to 9.0, pg_dump handled comments on large objects by dumping a bunch
of COMMENT commands into a single BLOB COMMENTS archive object.  With
sufficiently many such comments, some of the commands would likely get
split across bufferloads when restoring, causing failures in
direct-to-database restores (though no problem would be evident in text
output).  This is the same type of issue we have with table data dumped as
INSERT commands, and it can be fixed in the same way, by using a mini SQL
lexer to figure out where the command boundaries are.  Fortunately, the
COMMENT commands are no more complex to lex than INSERTs, so we can just
re-use the existing lexer for INSERTs.

Per bug #10611 from Jacek Zalewski.  Back-patch to all active branches.
2014-06-12 20:14:32 -04:00