PostgreSQL 歷史版本列表 Page26

更新時間：2014-02-21
更新細節：

What's new in this version:

Shore up GRANT ... WITH ADMIN OPTION restrictions:
- Granting a role without ADMIN OPTION is supposed to prevent the grantee from adding or removing members from the granted role, but this restriction was easily bypassed by doing SET ROLE first. The security impact is mostly that a role member can revoke the access of others, contrary to the wishes of his grantor. Unapproved role member additions are a lesser concern, since an uncooperative role member could provide most of his rights to others anyway by creating views or SECURITY DEFINER functions. (CVE-2014-0060) Prevent privilege escalation via manual calls to PL validator functions (Andres Freund):
- The primary role of PL validator functions is to be called implicitly during CREATE FUNCTION, but they are also normal SQL functions that a user can call explicitly. Calling a validator on a function actually written in some other language was not checked for and could be exploited for privilege-escalation purposes. The fix involves adding a call to a privilege-checking function in each validator function. Non-core procedural languages will also need to make this change to their own validator functions, if any. (CVE-2014-0061) Avoid multiple name lookups during table and index DDL (Robert Haas, Andres Freund):
- If the name lookups come to different conclusions due to concurrent activity, we might perform some parts of the DDL on a different table than other parts. At least in the case of CREATE INDEX, this can be used to cause the permissions checks to be performed against a different table than the index creation, allowing for a privilege escalation attack. (CVE-2014-0062) Prevent buffer overrun with long datetime strings (Noah Misch):
- The MAXDATELEN constant was too small for the longest possible value of type interval, allowing a buffer overrun in interval_out(). Although the datetime input functions were more careful about avoiding buffer overrun, the limit was short enough to cause them to reject some valid inputs, such as input containing a very long timezone name. The ecpg library contained these vulnerabilities along with some of its own. (CVE-2014-0063) Prevent buffer overrun due to integer overflow in size calculations (Noah Misch, Heikki Linnakangas):
- Several functions, mostly type input functions, calculated an allocation size without checking for overflow. If overflow did occur, a too-small buffer would be allocated and then written past. (CVE-2014-0064) Prevent overruns of fixed-size buffers (Peter Eisentraut, Jozef Mlich):
- Use strlcpy() and related functions to provide a clear guarantee that fixed-size buffers are not overrun. Unlike the preceding items, it is unclear whether these cases really represent live issues, since in most cases there appear to be previous constraints on the size of the input string. Nonetheless it seems prudent to silence all Coverity warnings of this type. (CVE-2014-0065) Avoid crashing if crypt() returns NULL (Honza Horak, Bruce Momjian):
- There are relatively few scenarios in which crypt() could return NULL, but contrib/chkpass would crash if it did. One practical case in which this could be an issue is if libc is configured to refuse to execute unapproved hashing algorithms (e.g., "FIPS mode"). (CVE-2014-0066) Document risks of make check in the regression testing instructions (Noah Misch, Tom Lane):
- Since the temporary server started by make check uses "trust" authentication, another user on the same machine could connect to it as database superuser, and then potentially exploit the privileges of the operating-system user who started the tests. A future release will probably incorporate changes in the testing procedure to prevent this risk, but some public discussion is needed first. So for the moment, just warn people against using make check when there are untrusted users on the same machine. (CVE-2014-0067) Rework tuple freezing protocol (Álvaro Herrera, Andres Freund):
- The logic for tuple freezing was unable to handle some cases involving freezing of multixact IDs, with the practical effect that shared row-level locks might be forgotten once old enough.
- Fixing this required changing the WAL record format for tuple freezing. While this is no issue for standalone servers, when using replication it means that standby servers must be upgraded to 9.3.3 or later before their masters are. An older standby will be unable to interpret freeze records generated by a newer master, and will fail with a PANIC message. (In such a case, upgrading the standby should be sufficient to let it resume execution.) Create separate GUC parameters to control multixact freezing (Álvaro Herrera):
- 9.3 requires multixact tuple labels to be frozen before they grow too old, in the same fashion as plain transaction ID labels have been frozen for some time. Previously, the transaction ID freezing parameters were used for multixact IDs too; but since the consumption rates of transaction IDs and multixact IDs can be quite different, this did not work very well. Introduce new settings vacuum_multixact_freeze_min_age, vacuum_multixact_freeze_table_age, and autovacuum_multixact_freeze_max_age to control when to freeze multixacts. Account for remote row locks propagated by local updates (Álvaro Herrera):
- If a row was locked by transaction A, and transaction B updated it, the new version of the row created by B would be locked by A, yet visible only to B. If transaction B then again updated the row, A's lock wouldn't get checked, thus possibly allowing B to complete when it shouldn't. This case is new in 9.3 since prior versions did not have any types of row locking that would permit another transaction to update the row at all.
- This oversight could allow referential integrity checks to give false positives (for instance, allow deletes that should have been rejected). Applications using the new commands SELECT FOR KEY SHARE and SELECT FOR NO KEY UPDATE might also have suffered locking failures of this kind. Prevent "forgetting" valid row locks when one of several holders of a row lock aborts (Álvaro Herrera):
- This was yet another mechanism by which a shared row lock could be lost, thus possibly allowing updates that should have been prevented by foreign-key constraints. Fix incorrect logic during update chain locking (Álvaro Herrera):
- This mistake could result in spurious "could not serialize access due to concurrent update" errors in REPEATABLE READ and SERIALIZABLE transaction isolation modes.
- Handle wraparound correctly during extension or truncation of pg_multixact/members (Andres Freund, Álvaro Herrera) Fix handling of 5-digit filenames in pg_multixact/members (Álvaro Herrera):
- As of 9.3, these names can be more than 4 digits, but the directory cleanup code ignored such files.
- Improve performance of multixact cache code (Álvaro Herrera)
- Optimize updating a row that's already locked by the same transaction (Andres Freund, Álvaro Herrera)
- This fixes a performance regression from pre-9.3 versions when doing SELECT FOR UPDATE followed by UPDATE/DELETE.
- During archive recovery, prefer highest timeline number when WAL segments with the same ID are present in both the archive and pg_xlog/ (Kyotaro Horiguchi)
- Previously, not-yet-archived segments could get ignored during recovery. This reverts an undesirable behavioral change in 9.3.0 back to the way things worked pre-9.3. Fix possible mis-replay of WAL records when some segments of a relation aren't full size (Greg Stark, Tom Lane):
- The WAL update could be applied to the wrong page, potentially many pages past where it should have been. Aside from corrupting data, this error has been observed to result in significant "bloat" of standby servers compared to their masters, due to updates being applied far beyond where the end-of-file should have been. This failure mode does not appear to be a significant risk during crash recovery, only when initially synchronizing a standby created from a base backup taken from a quickly-changing master. Fix bug in determining when recovery has reached consistency (Tomonari Katsumata, Heikki Linnakangas):
- In some cases WAL replay would mistakenly conclude that the database was already consistent at the start of replay, thus possibly allowing hot-standby queries before the database was really consistent. Other symptoms such as "PANIC: WAL contains references to invalid pages" were also possible. Fix WAL logging of visibility map changes (Heikki Linnakangas):
- Fix improper locking of btree index pages while replaying a VACUUM operation in hot-standby mode (Andres Freund, Heikki Linnakangas, Tom Lane)
- This error could result in "PANIC: WAL contains references to invalid pages" failures. Ensure that insertions into non-leaf GIN index pages write a full-page WAL record when appropriate (Heikki Linnakangas):
- The previous coding risked index corruption in the event of a partial-page write during a system crash.
- When pause_at_recovery_target and recovery_target_inclusive are both set, ensure the target record is applied before pausing, not after (Heikki Linnakangas)
- Ensure walreceiver sends hot-standby feedback messages on time even when there is a continuous stream of data (Andres Freund, Amit Kapila)
- Prevent timeout interrupts from taking control away from mainline code unless ImmediateInterruptOK is set (Andres Freund, Tom Lane)
- This is a serious issue for any application making use of statement timeouts, as it could cause all manner of strange failures after a timeout occurred. We have seen reports of "stuck" spinlocks, ERRORs being unexpectedly promoted to PANICs, unkillable backends, and other misbehaviors.
- Fix race conditions during server process exit (Robert Haas)
- Ensure that signal handlers don't attempt to use the process's MyProc pointer after it's no longer valid.
- Fix race conditions in walsender shutdown logic and walreceiver SIGHUP signal handler (Tom Lane)
- Fix unsafe references to errno within error reporting logic (Christian Kruse)
- This would typically lead to odd behaviors such as missing or inappropriate HINT fields.
- Fix possible crashes from using ereport() too early during server startup (Tom Lane)
- The principal case we've seen in the field is a crash if the server is started in a directory it doesn't have permission to read.
- Clear retry flags properly in OpenSSL socket write function (Alexander Kukushkin)
- This omission could result in a server lockup after unexpected loss of an SSL-encrypted connection.
- Fix length checking for Unicode identifiers (U&"..." syntax) containing escapes (Tom Lane)
- A spurious truncation warning would be printed for such identifiers if the escaped form of the identifier was too long, but the identifier actually didn't need truncation after de-escaping.
- Fix parsing of Unicode literals and identifiers just before the end of a command string or function body (Tom Lane)
- Allow keywords that are type names to be used in lists of roles (Stephen Frost)
- A previous patch allowed such keywords to be used without quoting in places such as role identifiers; but it missed cases where a list of role identifiers was permitted, such as DROP ROLE.
- Fix parser crash for EXISTS(SELECT * FROM zero_column_table) (Tom Lane)
- Fix possible crash due to invalid plan for nested sub-selects, such as WHERE (... x IN (SELECT ...) ...) IN (SELECT ...) (Tom Lane)
- Fix mishandling of WHERE conditions pulled up from a LATERAL subquery (Tom Lane)
- The typical symptom of this bug was a "JOIN qualification cannot refer to other relations" error, though subtle logic errors in created plans seem possible as well.
- Disallow LATERAL references to the target table of an UPDATE/DELETE (Tom Lane)
- While this might be allowed in some future release, it was unintentional in 9.3, and didn't work quite right anyway.
- Fix UPDATE/DELETE of an inherited target table that has UNION ALL subqueries (Tom Lane)
- Without this fix, UNION ALL subqueries aren't correctly inserted into the update plans for inheritance child tables after the first one, typically resulting in no update happening for those child table(s).
- Fix ANALYZE to not fail on a column that's a domain over a range type (Tom Lane)
- Ensure that ANALYZE creates statistics for a table column even when all the values in it are "too wide" (Tom Lane)
- ANALYZE intentionally omits very wide values from its histogram and most-common-values calculations, but it neglected to do something sane in the case that all the sampled entries are too wide.
- In ALTER TABLE ... SET TABLESPACE, allow the database's default tablespace to be used without a permissions check (Stephen Frost)
- CREATE TABLE has always allowed such usage, but ALTER TABLE didn't get the memo.
- Fix support for extensions containing event triggers (Tom Lane)
- Fix "cannot accept a set" error when some arms of a CASE return a set and others don't (Tom Lane)
- Fix memory leakage in JSON functions (Craig Ringer)
- Properly distinguish numbers from non-numbers when generating JSON output (Andrew Dunstan)
- Fix possible misclassification of multibyte characters by the text search parser (Tom Lane)
- Non-ASCII characters could be misclassified when using C locale with a multibyte encoding. On Cygwin, non-C locales could fail as well.
- Fix possible misbehavior in plainto_tsquery() (Heikki Linnakangas)
- Use memmove() not memcpy() for copying overlapping memory regions. There have been no field reports of this actually causing trouble, but it's certainly risky.
- Fix placement of permissions checks in pg_start_backup() and pg_stop_backup() (Andres Freund, Magnus Hagander)
- The previous coding might attempt to do catalog access when it shouldn't.
- Accept SHIFT_JIS as an encoding name for locale checking purposes (Tatsuo Ishii)
- Fix *-qualification of named parameters in SQL-language functions (Tom Lane)
- Given a composite-type parameter named foo, $1.* worked fine, but foo.* not so much.
- Fix misbehavior of PQhost() on Windows (Fujii Masao)
- It should return localhost if no host has been specified.
- Improve error handling in libpq and psql for failures during COPY TO STDOUT/FROM STDIN (Tom Lane)
- In particular this fixes an infinite loop that could occur in 9.2 and up if the server connection was lost during COPY FROM STDIN. Variants of that scenario might be possible in older versions, or with other client applications.
- Fix incorrect translation handling in some psql d commands (Peter Eisentraut, Tom Lane)
- Ensure pg_basebackup's background process is killed when exiting its foreground process (Magnus Hagander)
- Fix possible incorrect printing of filenames in pg_basebackup's verbose mode (Magnus Hagander)
- Avoid including tablespaces inside PGDATA twice in base backups (Dimitri Fontaine, Magnus Hagander)
- Fix misaligned descriptors in ecpg (MauMau)
- In ecpg, handle lack of a hostname in the connection parameters properly (Michael Meskes)
- Fix performance regression in contrib/dblink connection startup (Joe Conway)
- Avoid an unnecessary round trip when client and server encodings match.
- In contrib/isn, fix incorrect calculation of the check digit for ISMN values (Fabien Coelho)
- Fix contrib/pgbench's progress logging to avoid overflow when the scale factor is large (Tatsuo Ishii)
- Fix contrib/pg_stat_statement's handling of CURRENT_DATE and related constructs (Kyotaro Horiguchi)
- Improve lost-connection error handling in contrib/postgres_fdw (Tom Lane)
- Ensure client-code-only installation procedure works as documented (Peter Eisentraut)
- In Mingw and Cygwin builds, install the libpq DLL in the bin directory (Andrew Dunstan)
- This duplicates what the MSVC build has long done. It should fix problems with programs like psql failing to start because they can't find the DLL.
- Avoid using the deprecated dllwrap tool in Cygwin builds (Marco Atzeri)
- Enable building with Visual Studio 2013 (Brar Piening)
- Don't generate plain-text HISTORY and src/test/regress/README files anymore (Tom Lane)
- These text files duplicated the main HTML and PDF documentation formats. The trouble involved in maintaining them greatly outweighs the likely audience for plain-text format. Distribution tarballs will still contain files by these names, but they'll just be stubs directing the reader to consult the main documentation. The plain-text INSTALL file will still be maintained, as there is arguably a use-case for that.
- Update time zone data files to tzdata release 2013i for DST law changes in Jordan and historical changes in Cuba.
- In addition, the zones Asia/Riyadh87, Asia/Riyadh88, and Asia/Riyadh89 have been removed, as they are no longer maintained by IANA, and never represented actual civil timekeeping practice.

更新時間：2014-02-21
更新細節：

What's new in this version:

Shore up GRANT ... WITH ADMIN OPTION restrictions:
- Granting a role without ADMIN OPTION is supposed to prevent the grantee from adding or removing members from the granted role, but this restriction was easily bypassed by doing SET ROLE first. The security impact is mostly that a role member can revoke the access of others, contrary to the wishes of his grantor. Unapproved role member additions are a lesser concern, since an uncooperative role member could provide most of his rights to others anyway by creating views or SECURITY DEFINER functions. (CVE-2014-0060) Prevent privilege escalation via manual calls to PL validator functions (Andres Freund):
- The primary role of PL validator functions is to be called implicitly during CREATE FUNCTION, but they are also normal SQL functions that a user can call explicitly. Calling a validator on a function actually written in some other language was not checked for and could be exploited for privilege-escalation purposes. The fix involves adding a call to a privilege-checking function in each validator function. Non-core procedural languages will also need to make this change to their own validator functions, if any. (CVE-2014-0061) Avoid multiple name lookups during table and index DDL (Robert Haas, Andres Freund):
- If the name lookups come to different conclusions due to concurrent activity, we might perform some parts of the DDL on a different table than other parts. At least in the case of CREATE INDEX, this can be used to cause the permissions checks to be performed against a different table than the index creation, allowing for a privilege escalation attack. (CVE-2014-0062) Prevent buffer overrun with long datetime strings (Noah Misch):
- The MAXDATELEN constant was too small for the longest possible value of type interval, allowing a buffer overrun in interval_out(). Although the datetime input functions were more careful about avoiding buffer overrun, the limit was short enough to cause them to reject some valid inputs, such as input containing a very long timezone name. The ecpg library contained these vulnerabilities along with some of its own. (CVE-2014-0063) Prevent buffer overrun due to integer overflow in size calculations (Noah Misch, Heikki Linnakangas):
- Several functions, mostly type input functions, calculated an allocation size without checking for overflow. If overflow did occur, a too-small buffer would be allocated and then written past. (CVE-2014-0064) Prevent overruns of fixed-size buffers (Peter Eisentraut, Jozef Mlich):
- Use strlcpy() and related functions to provide a clear guarantee that fixed-size buffers are not overrun. Unlike the preceding items, it is unclear whether these cases really represent live issues, since in most cases there appear to be previous constraints on the size of the input string. Nonetheless it seems prudent to silence all Coverity warnings of this type. (CVE-2014-0065) Avoid crashing if crypt() returns NULL (Honza Horak, Bruce Momjian):
- There are relatively few scenarios in which crypt() could return NULL, but contrib/chkpass would crash if it did. One practical case in which this could be an issue is if libc is configured to refuse to execute unapproved hashing algorithms (e.g., "FIPS mode"). (CVE-2014-0066) Document risks of make check in the regression testing instructions (Noah Misch, Tom Lane):
- Since the temporary server started by make check uses "trust" authentication, another user on the same machine could connect to it as database superuser, and then potentially exploit the privileges of the operating-system user who started the tests. A future release will probably incorporate changes in the testing procedure to prevent this risk, but some public discussion is needed first. So for the moment, just warn people against using make check when there are untrusted users on the same machine. (CVE-2014-0067) Rework tuple freezing protocol (Álvaro Herrera, Andres Freund):
- The logic for tuple freezing was unable to handle some cases involving freezing of multixact IDs, with the practical effect that shared row-level locks might be forgotten once old enough.
- Fixing this required changing the WAL record format for tuple freezing. While this is no issue for standalone servers, when using replication it means that standby servers must be upgraded to 9.3.3 or later before their masters are. An older standby will be unable to interpret freeze records generated by a newer master, and will fail with a PANIC message. (In such a case, upgrading the standby should be sufficient to let it resume execution.) Create separate GUC parameters to control multixact freezing (Álvaro Herrera):
- 9.3 requires multixact tuple labels to be frozen before they grow too old, in the same fashion as plain transaction ID labels have been frozen for some time. Previously, the transaction ID freezing parameters were used for multixact IDs too; but since the consumption rates of transaction IDs and multixact IDs can be quite different, this did not work very well. Introduce new settings vacuum_multixact_freeze_min_age, vacuum_multixact_freeze_table_age, and autovacuum_multixact_freeze_max_age to control when to freeze multixacts. Account for remote row locks propagated by local updates (Álvaro Herrera):
- If a row was locked by transaction A, and transaction B updated it, the new version of the row created by B would be locked by A, yet visible only to B. If transaction B then again updated the row, A's lock wouldn't get checked, thus possibly allowing B to complete when it shouldn't. This case is new in 9.3 since prior versions did not have any types of row locking that would permit another transaction to update the row at all.
- This oversight could allow referential integrity checks to give false positives (for instance, allow deletes that should have been rejected). Applications using the new commands SELECT FOR KEY SHARE and SELECT FOR NO KEY UPDATE might also have suffered locking failures of this kind. Prevent "forgetting" valid row locks when one of several holders of a row lock aborts (Álvaro Herrera):
- This was yet another mechanism by which a shared row lock could be lost, thus possibly allowing updates that should have been prevented by foreign-key constraints. Fix incorrect logic during update chain locking (Álvaro Herrera):
- This mistake could result in spurious "could not serialize access due to concurrent update" errors in REPEATABLE READ and SERIALIZABLE transaction isolation modes.
- Handle wraparound correctly during extension or truncation of pg_multixact/members (Andres Freund, Álvaro Herrera) Fix handling of 5-digit filenames in pg_multixact/members (Álvaro Herrera):
- As of 9.3, these names can be more than 4 digits, but the directory cleanup code ignored such files.
- Improve performance of multixact cache code (Álvaro Herrera)
- Optimize updating a row that's already locked by the same transaction (Andres Freund, Álvaro Herrera)
- This fixes a performance regression from pre-9.3 versions when doing SELECT FOR UPDATE followed by UPDATE/DELETE.
- During archive recovery, prefer highest timeline number when WAL segments with the same ID are present in both the archive and pg_xlog/ (Kyotaro Horiguchi)
- Previously, not-yet-archived segments could get ignored during recovery. This reverts an undesirable behavioral change in 9.3.0 back to the way things worked pre-9.3. Fix possible mis-replay of WAL records when some segments of a relation aren't full size (Greg Stark, Tom Lane):
- The WAL update could be applied to the wrong page, potentially many pages past where it should have been. Aside from corrupting data, this error has been observed to result in significant "bloat" of standby servers compared to their masters, due to updates being applied far beyond where the end-of-file should have been. This failure mode does not appear to be a significant risk during crash recovery, only when initially synchronizing a standby created from a base backup taken from a quickly-changing master. Fix bug in determining when recovery has reached consistency (Tomonari Katsumata, Heikki Linnakangas):
- In some cases WAL replay would mistakenly conclude that the database was already consistent at the start of replay, thus possibly allowing hot-standby queries before the database was really consistent. Other symptoms such as "PANIC: WAL contains references to invalid pages" were also possible. Fix WAL logging of visibility map changes (Heikki Linnakangas):
- Fix improper locking of btree index pages while replaying a VACUUM operation in hot-standby mode (Andres Freund, Heikki Linnakangas, Tom Lane)
- This error could result in "PANIC: WAL contains references to invalid pages" failures. Ensure that insertions into non-leaf GIN index pages write a full-page WAL record when appropriate (Heikki Linnakangas):
- The previous coding risked index corruption in the event of a partial-page write during a system crash.
- When pause_at_recovery_target and recovery_target_inclusive are both set, ensure the target record is applied before pausing, not after (Heikki Linnakangas)
- Ensure walreceiver sends hot-standby feedback messages on time even when there is a continuous stream of data (Andres Freund, Amit Kapila)
- Prevent timeout interrupts from taking control away from mainline code unless ImmediateInterruptOK is set (Andres Freund, Tom Lane)
- This is a serious issue for any application making use of statement timeouts, as it could cause all manner of strange failures after a timeout occurred. We have seen reports of "stuck" spinlocks, ERRORs being unexpectedly promoted to PANICs, unkillable backends, and other misbehaviors.
- Fix race conditions during server process exit (Robert Haas)
- Ensure that signal handlers don't attempt to use the process's MyProc pointer after it's no longer valid.
- Fix race conditions in walsender shutdown logic and walreceiver SIGHUP signal handler (Tom Lane)
- Fix unsafe references to errno within error reporting logic (Christian Kruse)
- This would typically lead to odd behaviors such as missing or inappropriate HINT fields.
- Fix possible crashes from using ereport() too early during server startup (Tom Lane)
- The principal case we've seen in the field is a crash if the server is started in a directory it doesn't have permission to read.
- Clear retry flags properly in OpenSSL socket write function (Alexander Kukushkin)
- This omission could result in a server lockup after unexpected loss of an SSL-encrypted connection.
- Fix length checking for Unicode identifiers (U&"..." syntax) containing escapes (Tom Lane)
- A spurious truncation warning would be printed for such identifiers if the escaped form of the identifier was too long, but the identifier actually didn't need truncation after de-escaping.
- Fix parsing of Unicode literals and identifiers just before the end of a command string or function body (Tom Lane)
- Allow keywords that are type names to be used in lists of roles (Stephen Frost)
- A previous patch allowed such keywords to be used without quoting in places such as role identifiers; but it missed cases where a list of role identifiers was permitted, such as DROP ROLE.
- Fix parser crash for EXISTS(SELECT * FROM zero_column_table) (Tom Lane)
- Fix possible crash due to invalid plan for nested sub-selects, such as WHERE (... x IN (SELECT ...) ...) IN (SELECT ...) (Tom Lane)
- Fix mishandling of WHERE conditions pulled up from a LATERAL subquery (Tom Lane)
- The typical symptom of this bug was a "JOIN qualification cannot refer to other relations" error, though subtle logic errors in created plans seem possible as well.
- Disallow LATERAL references to the target table of an UPDATE/DELETE (Tom Lane)
- While this might be allowed in some future release, it was unintentional in 9.3, and didn't work quite right anyway.
- Fix UPDATE/DELETE of an inherited target table that has UNION ALL subqueries (Tom Lane)
- Without this fix, UNION ALL subqueries aren't correctly inserted into the update plans for inheritance child tables after the first one, typically resulting in no update happening for those child table(s).
- Fix ANALYZE to not fail on a column that's a domain over a range type (Tom Lane)
- Ensure that ANALYZE creates statistics for a table column even when all the values in it are "too wide" (Tom Lane)
- ANALYZE intentionally omits very wide values from its histogram and most-common-values calculations, but it neglected to do something sane in the case that all the sampled entries are too wide.
- In ALTER TABLE ... SET TABLESPACE, allow the database's default tablespace to be used without a permissions check (Stephen Frost)
- CREATE TABLE has always allowed such usage, but ALTER TABLE didn't get the memo.
- Fix support for extensions containing event triggers (Tom Lane)
- Fix "cannot accept a set" error when some arms of a CASE return a set and others don't (Tom Lane)
- Fix memory leakage in JSON functions (Craig Ringer)
- Properly distinguish numbers from non-numbers when generating JSON output (Andrew Dunstan)
- Fix possible misclassification of multibyte characters by the text search parser (Tom Lane)
- Non-ASCII characters could be misclassified when using C locale with a multibyte encoding. On Cygwin, non-C locales could fail as well.
- Fix possible misbehavior in plainto_tsquery() (Heikki Linnakangas)
- Use memmove() not memcpy() for copying overlapping memory regions. There have been no field reports of this actually causing trouble, but it's certainly risky.
- Fix placement of permissions checks in pg_start_backup() and pg_stop_backup() (Andres Freund, Magnus Hagander)
- The previous coding might attempt to do catalog access when it shouldn't.
- Accept SHIFT_JIS as an encoding name for locale checking purposes (Tatsuo Ishii)
- Fix *-qualification of named parameters in SQL-language functions (Tom Lane)
- Given a composite-type parameter named foo, $1.* worked fine, but foo.* not so much.
- Fix misbehavior of PQhost() on Windows (Fujii Masao)
- It should return localhost if no host has been specified.
- Improve error handling in libpq and psql for failures during COPY TO STDOUT/FROM STDIN (Tom Lane)
- In particular this fixes an infinite loop that could occur in 9.2 and up if the server connection was lost during COPY FROM STDIN. Variants of that scenario might be possible in older versions, or with other client applications.
- Fix incorrect translation handling in some psql d commands (Peter Eisentraut, Tom Lane)
- Ensure pg_basebackup's background process is killed when exiting its foreground process (Magnus Hagander)
- Fix possible incorrect printing of filenames in pg_basebackup's verbose mode (Magnus Hagander)
- Avoid including tablespaces inside PGDATA twice in base backups (Dimitri Fontaine, Magnus Hagander)
- Fix misaligned descriptors in ecpg (MauMau)
- In ecpg, handle lack of a hostname in the connection parameters properly (Michael Meskes)
- Fix performance regression in contrib/dblink connection startup (Joe Conway)
- Avoid an unnecessary round trip when client and server encodings match.
- In contrib/isn, fix incorrect calculation of the check digit for ISMN values (Fabien Coelho)
- Fix contrib/pgbench's progress logging to avoid overflow when the scale factor is large (Tatsuo Ishii)
- Fix contrib/pg_stat_statement's handling of CURRENT_DATE and related constructs (Kyotaro Horiguchi)
- Improve lost-connection error handling in contrib/postgres_fdw (Tom Lane)
- Ensure client-code-only installation procedure works as documented (Peter Eisentraut)
- In Mingw and Cygwin builds, install the libpq DLL in the bin directory (Andrew Dunstan)
- This duplicates what the MSVC build has long done. It should fix problems with programs like psql failing to start because they can't find the DLL.
- Avoid using the deprecated dllwrap tool in Cygwin builds (Marco Atzeri)
- Enable building with Visual Studio 2013 (Brar Piening)
- Don't generate plain-text HISTORY and src/test/regress/README files anymore (Tom Lane)
- These text files duplicated the main HTML and PDF documentation formats. The trouble involved in maintaining them greatly outweighs the likely audience for plain-text format. Distribution tarballs will still contain files by these names, but they'll just be stubs directing the reader to consult the main documentation. The plain-text INSTALL file will still be maintained, as there is arguably a use-case for that.
- Update time zone data files to tzdata release 2013i for DST law changes in Jordan and historical changes in Cuba.
- In addition, the zones Asia/Riyadh87, Asia/Riyadh88, and Asia/Riyadh89 have been removed, as they are no longer maintained by IANA, and never represented actual civil timekeeping practice.

更新時間：2013-12-06
更新細節：

What's new in this version:

- Fix VACUUM's tests to see whether it can update relfrozenxid
- Fix multiple bugs in MultiXactId freezing
- Fix initialization of pg_clog and pg_subtrans during hot standby startup
- Fix multiple bugs in update chain traversal
- Fix dangling-pointer problem in fast-path locking
- Fix assorted race conditions in timeout management
- Truncate pg_multixact contents during WAL replay
- Ensure an anti-wraparound VACUUM counts a page as scanned when it's only verified that no tuples need freezing
- Fix full-table-vacuum request mechanism for MultiXactIds
- Fix race condition in GIN index posting tree page deletion
- Fix "unexpected spgdoinsert() failure" error during SP-GiST index creation
- Fix assorted bugs in materialized views
- Re-allow duplicate table aliases if they're within aliased JOINs
- Avoid flattening a subquery whose SELECT list contains a volatile function wrapped inside a sub-SELECT
- Fix planner's processing of non-simple-variable subquery outputs nested within outer joins
- Fix incorrect planning in cases where the same non-strict expression appears in multiple WHERE and outer JOIN equality clauses
- Fix planner crash with whole-row reference to a subquery
- Fix incorrect generation of optimized MIN()/MAX() plans for inheritance trees
- Fix premature deletion of temporary files
- Prevent intra-transaction memory leak when printing range values
- Fix memory leaks when reloading configuration files
- Prevent incorrect display of dropped columns in NOT NULL and CHECK constraint violation messages
- Allow default arguments and named-argument notation for window functions
- Suppress trailing whitespace on each line when pretty-printing rules and views
- Fix possible read past end of memory in rule printing
- Fix array slicing of int2vector and oidvector values
- Return a valid JSON value when converting an empty hstore value to json
- Fix incorrect behaviors when using a SQL-standard, simple GMT offset timezone
- Prevent possible misbehavior when logging translations of Windows error codes
- Properly quote generated command lines in pg_ctl
- Fix pg_dumpall to work when a source database sets default_transaction_read_only via ALTER DATABASE SET
- Fix pg_isready to handle its -d option properly
- Fix parsing of WAL file names in pg_receivexlog
- Report out-of-disk-space failures properly in pg_upgrade
- Make ecpg search for quoted cursor names case-sensitively
- Fix ecpg's processing of lists of variables declared varchar
- Make contrib/lo defend against incorrect trigger definitions
- Update time zone data files to tzdata release 2013h for DST law changes in Argentina, Brazil, Jordan, Libya, Liechtenstein, Morocco, and Palestine. Also, new timezone abbreviations WIB, WIT, WITA for Indonesia

更新時間：2013-12-06
更新細節：

What's new in this version:

- Fix VACUUM's tests to see whether it can update relfrozenxid
- Fix multiple bugs in MultiXactId freezing
- Fix initialization of pg_clog and pg_subtrans during hot standby startup
- Fix multiple bugs in update chain traversal
- Fix dangling-pointer problem in fast-path locking
- Fix assorted race conditions in timeout management
- Truncate pg_multixact contents during WAL replay
- Ensure an anti-wraparound VACUUM counts a page as scanned when it's only verified that no tuples need freezing
- Fix full-table-vacuum request mechanism for MultiXactIds
- Fix race condition in GIN index posting tree page deletion
- Fix "unexpected spgdoinsert() failure" error during SP-GiST index creation
- Fix assorted bugs in materialized views
- Re-allow duplicate table aliases if they're within aliased JOINs
- Avoid flattening a subquery whose SELECT list contains a volatile function wrapped inside a sub-SELECT
- Fix planner's processing of non-simple-variable subquery outputs nested within outer joins
- Fix incorrect planning in cases where the same non-strict expression appears in multiple WHERE and outer JOIN equality clauses
- Fix planner crash with whole-row reference to a subquery
- Fix incorrect generation of optimized MIN()/MAX() plans for inheritance trees
- Fix premature deletion of temporary files
- Prevent intra-transaction memory leak when printing range values
- Fix memory leaks when reloading configuration files
- Prevent incorrect display of dropped columns in NOT NULL and CHECK constraint violation messages
- Allow default arguments and named-argument notation for window functions
- Suppress trailing whitespace on each line when pretty-printing rules and views
- Fix possible read past end of memory in rule printing
- Fix array slicing of int2vector and oidvector values
- Return a valid JSON value when converting an empty hstore value to json
- Fix incorrect behaviors when using a SQL-standard, simple GMT offset timezone
- Prevent possible misbehavior when logging translations of Windows error codes
- Properly quote generated command lines in pg_ctl
- Fix pg_dumpall to work when a source database sets default_transaction_read_only via ALTER DATABASE SET
- Fix pg_isready to handle its -d option properly
- Fix parsing of WAL file names in pg_receivexlog
- Report out-of-disk-space failures properly in pg_upgrade
- Make ecpg search for quoted cursor names case-sensitively
- Fix ecpg's processing of lists of variables declared varchar
- Make contrib/lo defend against incorrect trigger definitions
- Update time zone data files to tzdata release 2013h for DST law changes in Argentina, Brazil, Jordan, Libya, Liechtenstein, Morocco, and Palestine. Also, new timezone abbreviations WIB, WIT, WITA for Indonesia

更新時間：2013-10-11
更新細節：

What's new in this version:

Changes:
- Update hstore extension with JSON functionality (Andrew Dunstan)

Users who installed hstore prior to 9.3.1 must execute:
- ALTER EXTENSION hstore UPDATE;
- to add two new JSON functions and a cast.
- Fix memory leak when creating range indexes (Heikki Linnakangas)
- Serializable snapshot fixes (Kevin Grittner, Heikki Linnakangas)
- Fix libpq SSL deadlock bug (Stephen Frost)
- Fix timeline handling bugs in pg_receivexlog (Heikki Linnakangas, Andrew Gierth)
- Prevent CREATE FUNCTION from checking SET variables unless function body checking is enabled (Tom Lane)
- Remove rare inaccurate warning during vacuum of index-less tables (Heikki Linnakangas)

更新時間：2013-10-11
更新細節：

What's new in this version:

Changes:
- Update hstore extension with JSON functionality (Andrew Dunstan)

Users who installed hstore prior to 9.3.1 must execute:
- ALTER EXTENSION hstore UPDATE;
- to add two new JSON functions and a cast.
- Fix memory leak when creating range indexes (Heikki Linnakangas)
- Serializable snapshot fixes (Kevin Grittner, Heikki Linnakangas)
- Fix libpq SSL deadlock bug (Stephen Frost)
- Fix timeline handling bugs in pg_receivexlog (Heikki Linnakangas, Andrew Gierth)
- Prevent CREATE FUNCTION from checking SET variables unless function body checking is enabled (Tom Lane)
- Remove rare inaccurate warning during vacuum of index-less tables (Heikki Linnakangas)

更新時間：2013-09-09
更新細節：

What's new in this version:

Major enhancements in PostgreSQL 9.3 include:
- Add materialized views
- Make simple views auto-updatable
- Add many features for the JSON data type, including operators and functions to extract elements from JSON values
- Implement SQL-standard LATERAL option for FROM-clause subqueries and function calls
- Allow foreign data wrappers to support writes (inserts/updates/deletes) on foreign tables
- Add a Postgres foreign data wrapper to allow access to other Postgres servers
- Add support for event triggers
- Add optional ability to checksum data pages and report corruption
- Prevent non-key-field row updates from blocking foreign key checks
- Greatly reduce System V shared memory requirements

更新時間：2013-09-09
更新細節：

What's new in this version:

Major enhancements in PostgreSQL 9.3 include:
- Add materialized views
- Make simple views auto-updatable
- Add many features for the JSON data type, including operators and functions to extract elements from JSON values
- Implement SQL-standard LATERAL option for FROM-clause subqueries and function calls
- Allow foreign data wrappers to support writes (inserts/updates/deletes) on foreign tables
- Add a Postgres foreign data wrapper to allow access to other Postgres servers
- Add support for event triggers
- Add optional ability to checksum data pages and report corruption
- Prevent non-key-field row updates from blocking foreign key checks
- Greatly reduce System V shared memory requirements

更新時間：2013-04-04
更新細節：

What's new in this version:

Changes:
- Fix insecure parsing of server command-line switches (Mitsumasa Kondo, Kyotaro Horiguchi)
- A connection request containing a database name that begins with "-" could be crafted to damage or destroy files within the server's data directory, even if the request is eventually rejected. (CVE-2013-1899)
- Reset OpenSSL randomness state in each postmaster child process (Marko Kreen). This avoids a scenario wherein random numbers generated by contrib/pgcrypto functions might be relatively easy for another database user to guess. The risk is only significant when the postmaster is configured with ssl = on but most connections don't use SSL encryption. (CVE-2013-1900)
- Make REPLICATION privilege checks test current user not authenticated user (Noah Misch)
- An unprivileged database user could exploit this mistake to call pg_start_backup() or pg_stop_backup(), thus possibly interfering with creation of routine backups. (CVE-2013-1901)
- Fix GiST indexes to not use "fuzzy" geometric comparisons when it's not appropriate to do so (Alexander Korotkov). The core geometric types perform comparisons using "fuzzy" equality, but gist_box_same must do exact comparisons, else GiST indexes using it might become inconsistent. After installing this update, users should REINDEX any GiST indexes on box, polygon, circle, or point columns, since all of these use gist_box_same.
- Fix erroneous range-union and penalty logic in GiST indexes that use contrib/btree_gist for variable-width data types, that is text, bytea, bit, and numeric columns (Tom Lane). These errors could result in inconsistent indexes in which some keys that are present would not be found by searches, and also in useless index bloat. Users are advised to REINDEX such indexes after installing this update.
- Fix bugs in GiST page splitting code for multi-column indexes (Tom Lane). These errors could result in inconsistent indexes in which some keys that are present would not be found by searches, and also in indexes that are unnecessarily inefficient to search. Users are advised to REINDEX multi-column GiST indexes after installing this update.
- Fix gist_point_consistent to handle fuzziness consistently (Alexander Korotkov)
- Index scans on GiST indexes on point columns would sometimes yield results different from a sequential scan, because gist_point_consistent disagreed with the underlying operator code about whether to do comparisons exactly or fuzzily.
- Fix buffer leak in WAL replay (Heikki Linnakangas). This bug could result in "incorrect local pin count" errors during replay, making recovery impossible.
- Ensure we do crash recovery before entering archive recovery, if the database was not stopped cleanly and a recovery.conf file is present (Heikki Linnakangas, Kyotaro Horiguchi, Mitsumasa Kondo). This is needed to ensure that the database is consistent in certain scenarios, such as initializing a standby server with a filesystem snapshot from a running server.
- Avoid deleting not-yet-archived WAL files during crash recovery (Heikki Linnakangas, Fujii Masao)
- Fix race condition in DELETE RETURNING (Tom Lane). Under the right circumstances, DELETE RETURNING could attempt to fetch data from a shared buffer that the current process no longer has any pin on. If some other process changed the buffer meanwhile, this would lead to garbage RETURNING output, or even a crash.
- Fix infinite-loop risk in regular expression compilation (Tom Lane, Don Porter)
- Fix potential null-pointer dereference in regular expression compilation (Tom Lane)
- Fix to_char() to use ASCII-only case-folding rules where appropriate (Tom Lane). This fixes misbehavior of some template patterns that should be locale-independent, but mishandled "I" and "i" in Turkish locales.
- Fix unwanted rejection of timestamp 1999-12-31 24:00:00 (Tom Lane)
- Fix SQL-language functions to be safely usable as support functions for range types (Tom Lane)
- Fix logic error when a single transaction does UNLISTEN then LISTEN (Tom Lane). The session wound up not listening for notify events at all, though it surely should listen in this case.
- Fix possible planner crash after columns have been added to a view that's depended on by another view (Tom Lane)
- Fix performance issue in EXPLAIN (ANALYZE, TIMING OFF) (Pavel Stehule)
- Remove useless "picksplit doesn't support secondary split" log messages (Josh Hansen, Tom Lane). This message seems to have been added in expectation of code that was never written, and probably never will be, since GiST's default handling of secondary splits is actually pretty good. So stop nagging end users about it.
- Remove vestigial secondary-split support in gist_box_picksplit() (Tom Lane). Not only was this implementation of secondary-split not better than the default implementation, it's actually worse. So remove it and let the default code path handle the case.
- Fix possible failure to send a session's last few transaction commit/abort counts to the statistics collector (Tom Lane)
- Eliminate memory leaks in PL/Perl's spi_prepare() function (Alex Hunsaker, Tom Lane)
- Fix pg_dumpall to handle database names containing "=" correctly (Heikki Linnakangas)
- Avoid crash in pg_dump when an incorrect connection string is given (Heikki Linnakangas). Ignore invalid indexes in pg_dump and pg_upgrade (Michael Paquier, Bruce Momjian). Dumping invalid indexes can cause problems at restore time, for example if the reason the index creation failed was because it tried to enforce a uniqueness condition not satisfied by the table's data. Also, if the index creation is in fact still in progress, it seems reasonable to consider it to be an uncommitted DDL change, which pg_dump wouldn't be expected to dump anyway. pg_upgrade now also skips invalid indexes rather than failing.
- In pg_basebackup, include only the current server version's subdirectory when backing up a tablespace (Heikki Linnakangas)
- Add a server version check in pg_basebackup and pg_receivexlog, so they fail cleanly with version combinations that won't work (Heikki Linnakangas)
- Fix contrib/dblink to handle inconsistent settings of DateStyle or IntervalStyle safely (Daniel Farina, Tom Lane). Previously, if the remote server had different settings of these parameters, ambiguous dates might be read incorrectly. This fix ensures that datetime and interval columns fetched by a dblink query will be interpreted correctly. Note however that inconsistent settings are still risky, since literal values appearing in SQL commands sent to the remote server might be interpreted differently than they would be locally.
- Fix contrib/pg_trgm's similarity() function to return zero for trigram-less strings (Tom Lane). Previously it returned NaN due to internal division by zero.
- Enable building PostgreSQL with Microsoft Visual Studio 2012 (Brar Piening, Noah Misch)
- Update time zone data files to tzdata release 2013b for DST law changes in Chile, Haiti, Morocco, Paraguay, and some Russian areas. Also, historical zone data corrections for numerous places. Also, update the time zone abbreviation files for recent changes in Russia and elsewhere: CHOT, GET, IRKT, KGT, KRAT, MAGT, MAWT, MSK, NOVT, OMST, TKT, VLAT, WST, YAKT, YEKT now follow their current meanings, and VOLT (Europe/Volgograd) and MIST (Antarctica/Macquarie) are added to the default abbreviations list.

更新時間：2013-04-04
更新細節：

What's new in this version:

Changes:
- Fix insecure parsing of server command-line switches (Mitsumasa Kondo, Kyotaro Horiguchi)
- A connection request containing a database name that begins with "-" could be crafted to damage or destroy files within the server's data directory, even if the request is eventually rejected. (CVE-2013-1899)
- Reset OpenSSL randomness state in each postmaster child process (Marko Kreen). This avoids a scenario wherein random numbers generated by contrib/pgcrypto functions might be relatively easy for another database user to guess. The risk is only significant when the postmaster is configured with ssl = on but most connections don't use SSL encryption. (CVE-2013-1900)
- Make REPLICATION privilege checks test current user not authenticated user (Noah Misch)
- An unprivileged database user could exploit this mistake to call pg_start_backup() or pg_stop_backup(), thus possibly interfering with creation of routine backups. (CVE-2013-1901)
- Fix GiST indexes to not use "fuzzy" geometric comparisons when it's not appropriate to do so (Alexander Korotkov). The core geometric types perform comparisons using "fuzzy" equality, but gist_box_same must do exact comparisons, else GiST indexes using it might become inconsistent. After installing this update, users should REINDEX any GiST indexes on box, polygon, circle, or point columns, since all of these use gist_box_same.
- Fix erroneous range-union and penalty logic in GiST indexes that use contrib/btree_gist for variable-width data types, that is text, bytea, bit, and numeric columns (Tom Lane). These errors could result in inconsistent indexes in which some keys that are present would not be found by searches, and also in useless index bloat. Users are advised to REINDEX such indexes after installing this update.
- Fix bugs in GiST page splitting code for multi-column indexes (Tom Lane). These errors could result in inconsistent indexes in which some keys that are present would not be found by searches, and also in indexes that are unnecessarily inefficient to search. Users are advised to REINDEX multi-column GiST indexes after installing this update.
- Fix gist_point_consistent to handle fuzziness consistently (Alexander Korotkov)
- Index scans on GiST indexes on point columns would sometimes yield results different from a sequential scan, because gist_point_consistent disagreed with the underlying operator code about whether to do comparisons exactly or fuzzily.
- Fix buffer leak in WAL replay (Heikki Linnakangas). This bug could result in "incorrect local pin count" errors during replay, making recovery impossible.
- Ensure we do crash recovery before entering archive recovery, if the database was not stopped cleanly and a recovery.conf file is present (Heikki Linnakangas, Kyotaro Horiguchi, Mitsumasa Kondo). This is needed to ensure that the database is consistent in certain scenarios, such as initializing a standby server with a filesystem snapshot from a running server.
- Avoid deleting not-yet-archived WAL files during crash recovery (Heikki Linnakangas, Fujii Masao)
- Fix race condition in DELETE RETURNING (Tom Lane). Under the right circumstances, DELETE RETURNING could attempt to fetch data from a shared buffer that the current process no longer has any pin on. If some other process changed the buffer meanwhile, this would lead to garbage RETURNING output, or even a crash.
- Fix infinite-loop risk in regular expression compilation (Tom Lane, Don Porter)
- Fix potential null-pointer dereference in regular expression compilation (Tom Lane)
- Fix to_char() to use ASCII-only case-folding rules where appropriate (Tom Lane). This fixes misbehavior of some template patterns that should be locale-independent, but mishandled "I" and "i" in Turkish locales.
- Fix unwanted rejection of timestamp 1999-12-31 24:00:00 (Tom Lane)
- Fix SQL-language functions to be safely usable as support functions for range types (Tom Lane)
- Fix logic error when a single transaction does UNLISTEN then LISTEN (Tom Lane). The session wound up not listening for notify events at all, though it surely should listen in this case.
- Fix possible planner crash after columns have been added to a view that's depended on by another view (Tom Lane)
- Fix performance issue in EXPLAIN (ANALYZE, TIMING OFF) (Pavel Stehule)
- Remove useless "picksplit doesn't support secondary split" log messages (Josh Hansen, Tom Lane). This message seems to have been added in expectation of code that was never written, and probably never will be, since GiST's default handling of secondary splits is actually pretty good. So stop nagging end users about it.
- Remove vestigial secondary-split support in gist_box_picksplit() (Tom Lane). Not only was this implementation of secondary-split not better than the default implementation, it's actually worse. So remove it and let the default code path handle the case.
- Fix possible failure to send a session's last few transaction commit/abort counts to the statistics collector (Tom Lane)
- Eliminate memory leaks in PL/Perl's spi_prepare() function (Alex Hunsaker, Tom Lane)
- Fix pg_dumpall to handle database names containing "=" correctly (Heikki Linnakangas)
- Avoid crash in pg_dump when an incorrect connection string is given (Heikki Linnakangas). Ignore invalid indexes in pg_dump and pg_upgrade (Michael Paquier, Bruce Momjian). Dumping invalid indexes can cause problems at restore time, for example if the reason the index creation failed was because it tried to enforce a uniqueness condition not satisfied by the table's data. Also, if the index creation is in fact still in progress, it seems reasonable to consider it to be an uncommitted DDL change, which pg_dump wouldn't be expected to dump anyway. pg_upgrade now also skips invalid indexes rather than failing.
- In pg_basebackup, include only the current server version's subdirectory when backing up a tablespace (Heikki Linnakangas)
- Add a server version check in pg_basebackup and pg_receivexlog, so they fail cleanly with version combinations that won't work (Heikki Linnakangas)
- Fix contrib/dblink to handle inconsistent settings of DateStyle or IntervalStyle safely (Daniel Farina, Tom Lane). Previously, if the remote server had different settings of these parameters, ambiguous dates might be read incorrectly. This fix ensures that datetime and interval columns fetched by a dblink query will be interpreted correctly. Note however that inconsistent settings are still risky, since literal values appearing in SQL commands sent to the remote server might be interpreted differently than they would be locally.
- Fix contrib/pg_trgm's similarity() function to return zero for trigram-less strings (Tom Lane). Previously it returned NaN due to internal division by zero.
- Enable building PostgreSQL with Microsoft Visual Studio 2012 (Brar Piening, Noah Misch)
- Update time zone data files to tzdata release 2013b for DST law changes in Chile, Haiti, Morocco, Paraguay, and some Russian areas. Also, historical zone data corrections for numerous places. Also, update the time zone abbreviation files for recent changes in Russia and elsewhere: CHOT, GET, IRKT, KGT, KRAT, MAGT, MAWT, MSK, NOVT, OMST, TKT, VLAT, WST, YAKT, YEKT now follow their current meanings, and VOLT (Europe/Volgograd) and MIST (Antarctica/Macquarie) are added to the default abbreviations list.