diff --git a/mysql/config/ac-macros/misc.m4 b/mysql/config/ac-macros/misc.m4

index 9c7b9ae..93c27c4 100644

--- a/mysql/config/ac-macros/misc.m4

+++ b/mysql/config/ac-macros/misc.m4

@@ -717,6 +717,28 @@ dnl END OF MYSQL_CHECK_MAX_INDEXES SECTION

 dnl ---------------------------------------------------------------------------

+dnl ---------------------------------------------------------------------------

+dnl Macro: MYSQL_CHECK_USERNAME_LENGTH

+dnl Sets USERNAME_LENGTH when --with-username-length is used

+dnl ---------------------------------------------------------------------------

+AC_DEFUN([MYSQL_CHECK_USERNAME_LENGTH], [

+  AC_ARG_WITH([username-length],

+              [

+  --with-username-length       Maximum username length, default 16],

+              [USERNAME_LENGTH="$withval"],

+              [USERNAME_LENGTH=16])

+  AC_MSG_CHECKING([username length])

+

+  AC_DEFINE_UNQUOTED([USERNAME_LENGTH], [$USERNAME_LENGTH], [Maximum username length])

+  AC_MSG_RESULT([$USERNAME_LENGTH])

+  AC_SUBST(USERNAME_LENGTH)

+

+])

+dnl ---------------------------------------------------------------------------

+dnl END OF MYSQL_CHECK_USERNAME_LENGTH SECTION

+dnl ---------------------------------------------------------------------------

+

+

 dnl MYSQL_NEEDS_MYSYS_NEW

 AC_DEFUN([MYSQL_NEEDS_MYSYS_NEW],

 [AC_CACHE_CHECK([needs mysys_new helpers], mysql_use_mysys_new,

diff --git a/mysql/configure.in b/mysql/configure.in

index 05a6620..d3508da 100644

--- a/mysql/configure.in

+++ b/mysql/configure.in

@@ -2571,6 +2571,7 @@ AC_SUBST(readline_h_ln_cmd)

 MYSQL_CHECK_BIG_TABLES

 MYSQL_CHECK_MAX_INDEXES

+MYSQL_CHECK_USERNAME_LENGTH

 MYSQL_CHECK_BDB

 MYSQL_CHECK_INNODB

 MYSQL_CHECK_EXAMPLEDB

diff --git a/mysql/include/mysql_com.h b/mysql/include/mysql_com.h

index 889579e..6c8cebf 100644

--- a/mysql/include/mysql_com.h

+++ b/mysql/include/mysql_com.h

@@ -22,7 +22,6 @@

 #define NAME_LEN	64		/* Field/table name length */

 #define HOSTNAME_LENGTH 60

-#define USERNAME_LENGTH 16

 #define SERVER_VERSION_LENGTH 60

 #define SQLSTATE_LENGTH 5

diff --git a/mysql/scripts/Makefile.am b/mysql/scripts/Makefile.am

index 161c8a5..c3442a2 100644

--- a/mysql/scripts/Makefile.am

+++ b/mysql/scripts/Makefile.am

@@ -25,6 +25,7 @@ bin_SCRIPTS =		@server_scripts@ \

 			mysql_config \

 			mysql_fix_privilege_tables \

 			mysql_fix_extensions \

+			mysql_fix_username_length \

 			mysql_setpermission \

 			mysql_secure_installation \

 			mysql_zap \

@@ -78,7 +79,8 @@ dist_pkgdata_DATA =	fill_help_tables.sql \

 			mysql_fix_privilege_tables.sql \

 			mysql_system_tables.sql \

 			mysql_system_tables_data.sql \

-			mysql_test_data_timezone.sql

+			mysql_test_data_timezone.sql \

+			mysql_fix_username_length.sql

 CLEANFILES =		@server_scripts@ \

 			make_binary_distribution \

@@ -87,6 +89,7 @@ CLEANFILES =		@server_scripts@ \

 			mysql_config \

 			mysql_fix_privilege_tables \

 			mysql_fix_extensions \

+			mysql_fix_username_length \

 			mysql_setpermission \

 			mysql_secure_installation \

 			mysql_zap \

@@ -99,6 +102,7 @@ CLEANFILES =		@server_scripts@ \

 			mysql_tableinfo \

 			mysql_upgrade_shell \

 			mysqld_multi \

+			mysql_fix_privilege_tables.sql \

 			make_win_src_distribution_old

 # mysqlbug should be distributed built so that people can report build

@@ -130,7 +134,7 @@ mysql_fix_privilege_tables_sql.c: comp_sql.c mysql_fix_privilege_tables.sql

 	    $(top_srcdir)/scripts/mysql_fix_privilege_tables.sql $@

-SUFFIXES = .sh

+SUFFIXES = .sh .in

 .sh:

 	@RM@ -f $@ $@-t

@@ -185,6 +189,11 @@ SUFFIXES = .sh

 	@CHMOD@ +x $@-t

 	@MV@ $@-t $@

+.in:

+	@RM@ -f $@

+	@SED@ \

+	  -e 's!@''USERNAME_LENGTH''@!@USERNAME_LENGTH@!' \

+	$< > $@

 # Don't update the files from bitkeeper

 %::SCCS/s.%