make sure that if builder configured with a non-standard (!= 3306)
default TCP port that value actually gets used throughout. if they
didn't configure a value, assume "use a sensible default", which
will be read from /etc/services or, failing that, from the factory
default. That makes the order of preference
- command-line option
- my.cnf, where applicable
- $MYSQL_TCP_PORT environment variable
- /etc/services (unless configured --with-tcp-port)
- default port (--with-tcp-port=... or factory default)


client/mysql.cc:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
client/mysql_upgrade.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
client/mysqladmin.cc:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
client/mysqlbinlog.cc:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
client/mysqlcheck.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
client/mysqldump.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
client/mysqlimport.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
client/mysqlmanagerc.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
configure.in:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  If MYSQL_TCP_PORT defaulted in configure (factory default 3306
  at the time of this writing), set MYSQL_TCP_PORT to factory
  default, then clear factory default after. That way, we lose no
  information, and we can distinguish between "defaulted" and the
  pathological case "builder specifically configured a port that
  coincides with factory default." This can in theory happen if
  builder configures and builds several servers from a script
  (--with-tcp-port=3306, --with-tcp-port=3316, --with-tcp-port=3326).
  Not all that probable, but much preferable to having more "magic"
  happen in the server when we can solve this without any guesswork.
client/mysqlshow.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
client/mysqltest.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
include/mysql_version.h.in:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make factory default for TCP port available as MYSQL_PORT_DEFAULT
  if build-time configured with a different default.  (0 if unchanged)
libmysql/libmysql.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  initialize default tcp port for client, like so:
  - if user configured --with-tcp-port, use that value as default
  - otherwise assume "use a good default": search mysqld/tcp in
    /etc/services; if that doesn't exist, use factory default (3306)
  - environment variable MYSQL_TCP_PORT overrides this default
  - command-line option overrides all of the above
mysql-test/Makefile.am:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make factory default for TCP port available as MYSQL_TCP_PORT_DEFAULT
  if build-time configured with a different default.  (0 if unchanged)
mysql-test/mysql-test-run-shell.sh:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  set up MYSQL_TCP_PORT if not already set in environment:
  - if user configured --with-tcp-port, use that value as default
  - otherwise assume "use a good default": search mysqld/tcp in
    /etc/services; if that doesn't exist, use factory default (3306)
netware/mysql_test_run.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  account for non-standard default port-no. configured at build-time
netware/mysqld_safe.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  account for non-standard default port-no. configured at build-time
scripts/Makefile.am:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make factory default for TCP port available as MYSQL_TCP_PORT_DEFAULT
  if build-time configured with a different default.  (0 if unchanged)
scripts/mysql_config.sh:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  set up MYSQL_TCP_PORT if not already set in environment:
  - if user configured --with-tcp-port, use that value as default
  - otherwise assume "use a good default": search mysqld/tcp in
    /etc/services; if that doesn't exist, use factory default (3306)
scripts/mysql_fix_privilege_tables.sh:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  clarifying notice only
scripts/mysqld_safe-watch.sh:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  account for non-standard default port-no. configured at build-time
server-tools/instance-manager/priv.h:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  account for non-standard default port-no. configured at build-time
sql/mysqld.cc:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  if builder specifically requested a default port, use that
  (even if it coincides with our factory default).
  only if they didn't do we check /etc/services (and, failing
  on that, fall back to the factory default of 3306).
  either default can be overridden by the environment variable
  MYSQL_TCP_PORT, which in turn can be overridden with command
  line options.
tests/mysql_client_test.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear
tests/ssl_test.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  account for non-standard default port-no. configured at build-time
tests/thread_test.c:
  Bug #15327: configure: --with-tcp-port option being partially ignored
  
  make help on --port a little more clear