PostgreSQL 9.5.4

- Fix possible mis-evaluation of nested CASE-WHEN expressions. A CASE expression appearing within the test value subexpression of another CASE could become confused about whether its own test value was null or not. Also, inlining of a SQL function implementing the equality operator used by a CASE expression could result in passing the wrong test value to functions called within a CASE expression in the SQL function's body. If the test values were of different data types, a crash might result; moreover such situations could be abused to allow disclosure of portions of server memory.
- Fix client programs' handling of special characters in database and role names.
- Fix corner-case misbehaviors for IS NULL/IS NOT NULL applied to nested composite values
- Fix "unrecognized node type" error for INSERT ... ON CONFLICT within a recursive CTE (a WITH item)
- Fix INSERT ... ON CONFLICT to successfully match index expressions or index predicates that are simplified during the planner's expression preprocessing phase
- Correctly handle violations of exclusion constraints that apply to the target table of an INSERT ... ON CONFLICT command, but are not one of the selected arbiter indexes Such a case should raise a normal constraint-violation error, but it got into an infinite loop instead.
- Fix INSERT ... ON CONFLICT to not fail if the target table has a unique index on OID
- Make the inet and cidr data types properly reject IPv6 addresses with too many colon-separated fields
- Prevent crash in close_ps() (the point ## lseg operator) for NaN input coordinates.Make it return NULL instead of crashing.
- Avoid possible crash in pg_get_expr() when inconsistent values are passed to it
- Fix several one-byte buffer over-reads in to_number()
- Do not run the planner on the query contained in CREATE MATERIALIZED VIEW or CREATE TABLE AS when WITH NO DATA is specified
- Avoid unsafe intermediate state during expensive paths through heap_update()
- Fix hint bit update during WAL replay of row locking operations
- Avoid unnecessary "could not serialize access" errors when acquiring FOR KEY SHARE row locks in serializable mode
- Make sure "expanded" datums returned by a plan node are read-only
- Avoid crash in postgres -C when the specified variable has a null string value
- Prevent unintended waits for the receiver in WAL sender processes
- Fix possible loss of large subtransactions in logical decoding
- Fix failure of logical decoding when a subtransaction contains no actual changes
- Ensure that backends see up-to-date statistics for shared catalogs
- Avoid redundant writes of the statistics files when multiple backends request updates close together
- Avoid consuming a transaction ID during VACUUM
- Prevent possible failure when vacuuming multixact IDs in an installation that has been pg_upgrade'd from pre-9.3
- When a manual ANALYZE specifies a column list, don't reset the table's changes_since_analyze counter
- Fix ANALYZE's overestimation of n_distinct for a unique or nearly-unique column with many null entries
- Prevent autovacuum from starting multiple workers for the same shared catalog
- Fix bug in b-tree mark/restore processing
- Avoid duplicate buffer lock release when abandoning a b-tree index page deletion attempt
- Fix building of large (bigger than shared_buffers) hash indexes
- Prevent infinite loop in GiST index build for geometric columns containing NaN component values
- Fix possible crash during a nearest-neighbor (ORDER BY distance) indexscan on a contrib/btree_gist index on an interval column
- Fix "PANIC: failed to add BRIN tuple" error when attempting to update a BRIN index entry
- Fix possible crash during background worker shutdown
- Fix PL/pgSQL's handling of the INTO clause within IMPORT FOREIGN SCHEMA commands
- Fix contrib/btree_gin to handle the smallest possible bigint value correctly
- Teach libpq to correctly decode server version from future servers
- Fix ecpg's code for unsigned long long array elements
- In pg_dump with both -c and -C options, avoid emitting an unwanted CREATE SCHEMA public command
- Improve handling of SIGTERM/control-C in parallel pg_dump and pg_restore
- Fix error reporting in parallel pg_dump and pg_restore
- Ensure that parallel pg_dump or pg_restore on Windows will shut down properly after an error
- Make parallel pg_dump fail cleanly when run against a standby server
- Make pg_dump behave better when built without zlib support
- Make pg_basebackup accept -Z 0 as specifying no compression
- Fix makefiles' rule for building AIX shared libraries to be safe for parallel make
- Fix TAP tests and MSVC scripts to work when build directory's path name contains spaces
- Be more predictable about reporting "statement timeout" versus "lock timeout"
- Make regression tests safe for Danish and Welsh locales
- Update our copy of the timezone code to match IANA's tzcode release 2016c
- Update time zone data files to tzdata release 2016f for DST law changes in Kemerovo and Novosibirsk, plus historical corrections for Azerbaijan, Belarus, and Morocco.