=== modified file 'sql/mysql_priv.h'
--- sql/mysql_priv.h	2008-08-26 18:38:17 +0000
+++ sql/mysql_priv.h	2008-08-28 00:52:14 +0000
@@ -1887,6 +1887,7 @@
 extern char glob_hostname[FN_REFLEN], mysql_home[FN_REFLEN];
 extern char pidfile_name[FN_REFLEN], system_time_zone[30], *opt_init_file;
 extern char log_error_file[FN_REFLEN], *opt_tc_log_file;
+extern char log_bin_name[FN_REFLEN];
 extern ulonglong log_10_int[20];
 extern ulonglong keybuff_size;
 extern ulonglong thd_startup_options;

=== modified file 'sql/mysqld.cc'
--- sql/mysqld.cc	2008-08-26 09:31:17 +0000
+++ sql/mysqld.cc	2008-08-28 00:52:14 +0000
@@ -515,6 +515,7 @@
 char mysql_home[FN_REFLEN], pidfile_name[FN_REFLEN], system_time_zone[30];
 char *default_tz_name;
 char log_error_file[FN_REFLEN], glob_hostname[FN_REFLEN];
+char log_bin_name[FN_REFLEN];
 char mysql_real_data_home[FN_REFLEN],
      language[FN_REFLEN], reg_ext[FN_EXTLEN], mysql_charsets_dir[FN_REFLEN],
      *opt_init_file, *opt_tc_log_file,
@@ -3810,6 +3811,7 @@
     {
       my_free(opt_bin_logname, MYF(MY_ALLOW_ZERO_PTR));
       opt_bin_logname=my_strdup(buf, MYF(0));
+      strmake(log_bin_name, opt_bin_logname, sizeof(log_bin_name)-1);
     }
     if (mysql_bin_log.open_index_file(opt_binlog_index_name, ln))
     {
@@ -7408,7 +7410,7 @@
 {
   /* Things reset to zero */
   opt_skip_slave_start= opt_reckless_slave = 0;
-  mysql_home[0]= pidfile_name[0]= log_error_file[0]= 0;
+  mysql_home[0]= pidfile_name[0]= log_error_file[0]= log_bin_name[0]= 0;
   myisam_test_invalid_symlink= test_if_data_home_dir;
   opt_log= opt_slow_log= 0;
   opt_update_log= 0;

=== modified file 'sql/set_var.cc'
--- sql/set_var.cc	2008-08-25 12:44:05 +0000
+++ sql/set_var.cc	2008-08-28 00:52:14 +0000
@@ -788,6 +788,7 @@
   {"locked_in_memory",	      (char*) &locked_in_memory,	    SHOW_MY_BOOL},
 #endif
   {"log_bin",                 (char*) &opt_bin_log,                 SHOW_BOOL},
+  {"log_bin_name",            (char*) &log_bin_name,                SHOW_CHAR},
   {"log_error",               (char*) log_error_file,               SHOW_CHAR},
   {"lower_case_file_system",  (char*) &lower_case_file_system,      SHOW_MY_BOOL},
   {"lower_case_table_names",  (char*) &lower_case_table_names,      SHOW_INT},