Merge branch '12.3' into 13.0

changed deprecation version for wsrep_slave_FK_checks,
because it was just deprecated this month

Author: vuvova

CMakeLists.txt

@@ -191,6 +191,15 @@ ELSE()
   SET (SKIP_COMPONENTS "N-O-N-E")
 ENDIF()
 
+# I/O buffer size. May be smaller than the disk page size.
+# 4096 is a common block size on SSDs.
+# This influences the speed of the isam btree library.
+# E.g.: too big may become too slow.
+SET(IO_SIZE 4096 CACHE STRING "Specify the I/O buffer size")
+MATH(EXPR IS_POWER_OF_TWO "(${IO_SIZE} & (${IO_SIZE} - 1))")
+IF(IO_SIZE LESS 512 OR NOT IS_POWER_OF_TWO EQUAL 0)
+  MESSAGE(FATAL_ERROR "IO_SIZE ${IO_SIZE} must be >= 512 and a power of 2.")
+ENDIF()
 
 SET(MEMPROTECT_DEFAULT ON)
 
@@ -265,6 +274,16 @@ IF (WITH_MSAN)
   ENDIF()
 ENDIF()
 
+# SANs, with their additional processing workload, should have a basic
+# but debuggable optimization unless user specifies otherwise.
+IF((WITH_ASAN OR WITH_UBSAN OR WITH_TSAN OR WITH_MSAN)
+	AND NOT CMAKE_C_FLAGS MATCHES "-O[0-9sgzf]"
+	AND NOT CMAKE_CXX_FLAGS MATCHES "-O[0-9sgzf]"
+	AND NOT CMAKE_C_FLAGS_${CMAKE_BUILD_TYPE} MATCHES "-O[0-9sgzf]"
+	AND NOT CMAKE_CXX_FLAGS_${CMAKE_BUILD_TYPE} MATCHES "-O[0-9sgzf]")
+  MY_CHECK_AND_SET_COMPILER_FLAG("-Og")
+ENDIF()
+
 OPTION(WITH_GPROF "Enable profiling with gprof" OFF)
 IF (WITH_GPROF)
   MY_CHECK_AND_SET_COMPILER_FLAG("-pg -g -no-pie -fPIC")
@@ -565,9 +584,6 @@ INSTALL_DOCUMENTATION(README.md CREDITS COPYING THIRDPARTY COMPONENT Readme)
 
 IF(UNIX)
   INSTALL_DOCUMENTATION(Docs/INSTALL-BINARY COMPONENT Readme)
-  IF(WITH_WSREP)
-    INSTALL_DOCUMENTATION(Docs/README-wsrep COMPONENT Readme)
-  ENDIF()
 ENDIF()
 
 INCLUDE(build_depends)

CONTRIBUTING.md

@@ -15,14 +15,16 @@ MariaDB Server has a vibrant community contributing in a wide range of areas. Th
 -   Contribute towards [documenting MariaDB Server](https://mariadb.com/docs/general-resources/about/readme/contributing-documentation)  and its ecosystem by adding new content or improving existing content.
 -   [Translate](https://mariadb.com/docs/general-resources/about/readme/contributing-documentation)  existing documentation.
 
-### Help debug and develop MariaDB
+### Help develop MariaDB
 -----
--   [Report bugs](https://jira.mariadb.org/)
--   Test development versions
--   Write code to fix bugs or develop new features (see  [Getting Started for Developers](https://mariadb.org/getting-started-for-developers)).See also [list of beginner friendly tasks](https://jira.mariadb.org/browse/MDEV-15736?jql=resolution%20%3D%20Unresolved%20AND%20labels%20%3D%20beginner-friendly%20ORDER%20BY%20updated%20DESC)
--   Help with code quality control
--   Participate in packaging for different Linux distributions
--   Coding standards for the main source code can be found in [CODING_STANDARDS.md](CODING_STANDARDS.md).
+-   Fix bugs or develop new features
+-   Review code contributions
+-   Test bug fixes and features
+-   Participate in packaging for different distributions
+
+Check the [list of beginner friendly tasks](https://jira.mariadb.org/issues/?jql=status%3DConfirmed%20AND%20labels%3Dbeginner-friendly%20ORDER%20BY%20updated%20DESC). Or talk to the [MariaDB developers](#engage-online-with-other-community-members).
+
+See also [Getting Started for Developers](https://mariadb.org/getting-started-for-developers). Coding standards for the main source code can be found in [CODING_STANDARDS.md](CODING_STANDARDS.md).
 
 ### Sponsor or donate
 ---
@@ -34,7 +36,7 @@ You’re very welcome to support MariaDB Server as an individual, or talk your c
     -   [Events and Conferences page](https://mariadb.org/events/)
     -   [mariadb.meetup.com](http://mariadb.meetup.com/)
 
-### Live QA for beginner contributors
+### Live Q&A for beginner contributors
 ----
 MariaDB has a dedicated time each week when we answer new contributor questions live on Zulip.
 From 8:00 to 10:00 UTC on Mondays, and 10:00 to 12:00 UTC on Thursdays, anyone can ask any questions they’d like,
@@ -43,5 +45,5 @@ New contributors can ask questions any time, but we will provide immediate feedb
 
 ### Additional resources
 ----
- - [MariaDB Foundation ](https://mariadb.org/)
+ - [MariaDB Foundation](https://mariadb.org/)
  - [MariaDB Documentation](https://mariadb.com/docs/)