merging from the 5.5 repo to local branch.

include/my_global.h

@@ -1364,11 +1364,31 @@ do { doubleget_union _tmp; \
 
 #ifndef HAVE_DLERROR
 #ifdef _WIN32
+#define DLERROR_GENERATE(errmsg, error_number) \
+  char win_errormsg[2048]; \
+  if(FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, \
+                   0, error_number, 0, win_errormsg, 2048, NULL)) \
+  { \
+    char *ptr; \
+    for (ptr= &win_errormsg[0] + strlen(win_errormsg) - 1; \
+         ptr >= &win_errormsg[0] && strchr("\r\n\t\0x20", *ptr); \
+         ptr--) \
+      *ptr= 0; \
+    errmsg= win_errormsg; \
+  } \
+  else \
+    errmsg= ""
 #define dlerror() ""
-#else
+#define dlopen_errno GetLastError()
+#else /* _WIN32 */
 #define dlerror() "No support for dynamic loading (static build?)"
-#endif
-#endif
+#define DLERROR_GENERATE(errmsg, error_number) errmsg= dlerror()
+#define dlopen_errno errno
+#endif /* _WIN32 */
+#else /* HAVE_DLERROR */
+#define DLERROR_GENERATE(errmsg, error_number) errmsg= dlerror()
+#define dlopen_errno errno
+#endif /* HAVE_DLERROR */
 
 
 /*

mysql-test/suite/sys_vars/r/all_vars.result

@@ -3,8 +3,6 @@ create table t2 (variable_name text);
 load data infile "MYSQLTEST_VARDIR/tmp/sys_vars.all_vars.txt" into table t1;
 insert into t2 select variable_name from information_schema.global_variables;
 insert into t2 select variable_name from information_schema.session_variables;
-delete from t2 where variable_name='innodb_change_buffering_debug';
-delete from t2 where variable_name='innodb_trx_rseg_n_slots_debug';
 update t2 set variable_name= replace(variable_name, "PERFORMANCE_SCHEMA_", "PFS_");
 select variable_name as `There should be *no* long test name listed below:` from t2
 where length(variable_name) > 50;

mysql-test/suite/sys_vars/r/character_sets_dir_basic.result

 select @@global.character_sets_dir;
 @@global.character_sets_dir
-MYSQL_CHARSETSDIR/
+MYSQL_CHARSETSDIR
 select @@session.character_sets_dir;
 ERROR HY000: Variable 'character_sets_dir' is a GLOBAL variable
 show global variables like 'character_sets_dir';
 Variable_name	Value
-character_sets_dir	MYSQL_CHARSETSDIR/
+character_sets_dir	MYSQL_CHARSETSDIR
 show session variables like 'character_sets_dir';
 Variable_name	Value
-character_sets_dir	MYSQL_CHARSETSDIR/
+character_sets_dir	MYSQL_CHARSETSDIR
 select * from information_schema.global_variables where variable_name='character_sets_dir';
 VARIABLE_NAME	VARIABLE_VALUE
-CHARACTER_SETS_DIR	MYSQL_CHARSETSDIR/
+CHARACTER_SETS_DIR	MYSQL_CHARSETSDIR
 select * from information_schema.session_variables where variable_name='character_sets_dir';
 VARIABLE_NAME	VARIABLE_VALUE
-CHARACTER_SETS_DIR	MYSQL_CHARSETSDIR/
+CHARACTER_SETS_DIR	MYSQL_CHARSETSDIR
 set global character_sets_dir="foo";
 ERROR HY000: Variable 'character_sets_dir' is a read only variable
 set session character_sets_dir="foo";

mysql-test/suite/sys_vars/r/innodb_change_buffering_debug_basic.result

+SET @start_global_value = @@global.innodb_change_buffering_debug;
+SELECT @start_global_value;
+@start_global_value
+0
+select @@global.innodb_change_buffering_debug in (0, 1);
+@@global.innodb_change_buffering_debug in (0, 1)
+1
+select @@global.innodb_change_buffering_debug;
+@@global.innodb_change_buffering_debug
+0
+select @@session.innodb_change_buffering_debug;
+ERROR HY000: Variable 'innodb_change_buffering_debug' is a GLOBAL variable
+show global variables like 'innodb_change_buffering_debug';
+Variable_name	Value
+innodb_change_buffering_debug	0
+show session variables like 'innodb_change_buffering_debug';
+Variable_name	Value
+innodb_change_buffering_debug	0
+select * from information_schema.global_variables where variable_name='innodb_change_buffering_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_CHANGE_BUFFERING_DEBUG	0
+select * from information_schema.session_variables where variable_name='innodb_change_buffering_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_CHANGE_BUFFERING_DEBUG	0
+set global innodb_change_buffering_debug=1;
+select @@global.innodb_change_buffering_debug;
+@@global.innodb_change_buffering_debug
+1
+select * from information_schema.global_variables where variable_name='innodb_change_buffering_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_CHANGE_BUFFERING_DEBUG	1
+select * from information_schema.session_variables where variable_name='innodb_change_buffering_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_CHANGE_BUFFERING_DEBUG	1
+set @@global.innodb_change_buffering_debug=0;
+select @@global.innodb_change_buffering_debug;
+@@global.innodb_change_buffering_debug
+0
+select * from information_schema.global_variables where variable_name='innodb_change_buffering_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_CHANGE_BUFFERING_DEBUG	0
+select * from information_schema.session_variables where variable_name='innodb_change_buffering_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_CHANGE_BUFFERING_DEBUG	0
+set session innodb_change_buffering_debug='some';
+ERROR HY000: Variable 'innodb_change_buffering_debug' is a GLOBAL variable and should be set with SET GLOBAL
+set @@session.innodb_change_buffering_debug='some';
+ERROR HY000: Variable 'innodb_change_buffering_debug' is a GLOBAL variable and should be set with SET GLOBAL
+set global innodb_change_buffering_debug=1.1;
+ERROR 42000: Incorrect argument type to variable 'innodb_change_buffering_debug'
+set global innodb_change_buffering_debug='foo';
+ERROR 42000: Incorrect argument type to variable 'innodb_change_buffering_debug'
+set global innodb_change_buffering_debug=-2;
+Warnings:
+Warning	1292	Truncated incorrect innodb_change_buffering_debug value: '-2'
+set global innodb_change_buffering_debug=1e1;
+ERROR 42000: Incorrect argument type to variable 'innodb_change_buffering_debug'
+set global innodb_change_buffering_debug=2;
+Warnings:
+Warning	1292	Truncated incorrect innodb_change_buffering_debug value: '2'
+SET @@global.innodb_change_buffering_debug = @start_global_value;
+SELECT @@global.innodb_change_buffering_debug;
+@@global.innodb_change_buffering_debug
+0

mysql-test/suite/sys_vars/r/innodb_trx_rseg_n_slots_debug_basic.result

+SET @start_global_value = @@global.innodb_trx_rseg_n_slots_debug;
+SELECT @start_global_value;
+@start_global_value
+0
+select @@global.innodb_trx_rseg_n_slots_debug between 0 and 1024;
+@@global.innodb_trx_rseg_n_slots_debug between 0 and 1024
+1
+select @@global.innodb_trx_rseg_n_slots_debug;
+@@global.innodb_trx_rseg_n_slots_debug
+0
+select @@session.innodb_trx_rseg_n_slots_debug;
+ERROR HY000: Variable 'innodb_trx_rseg_n_slots_debug' is a GLOBAL variable
+show global variables like 'innodb_trx_rseg_n_slots_debug';
+Variable_name	Value
+innodb_trx_rseg_n_slots_debug	0
+show session variables like 'innodb_trx_rseg_n_slots_debug';
+Variable_name	Value
+innodb_trx_rseg_n_slots_debug	0
+select * from information_schema.global_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_TRX_RSEG_N_SLOTS_DEBUG	0
+select * from information_schema.session_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_TRX_RSEG_N_SLOTS_DEBUG	0
+set global innodb_trx_rseg_n_slots_debug=1;
+select @@global.innodb_trx_rseg_n_slots_debug;
+@@global.innodb_trx_rseg_n_slots_debug
+1
+select * from information_schema.global_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_TRX_RSEG_N_SLOTS_DEBUG	1
+select * from information_schema.session_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_TRX_RSEG_N_SLOTS_DEBUG	1
+set @@global.innodb_trx_rseg_n_slots_debug=0;
+select @@global.innodb_trx_rseg_n_slots_debug;
+@@global.innodb_trx_rseg_n_slots_debug
+0
+select * from information_schema.global_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_TRX_RSEG_N_SLOTS_DEBUG	0
+select * from information_schema.session_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+VARIABLE_NAME	VARIABLE_VALUE
+INNODB_TRX_RSEG_N_SLOTS_DEBUG	0
+set session innodb_trx_rseg_n_slots_debug='some';
+ERROR HY000: Variable 'innodb_trx_rseg_n_slots_debug' is a GLOBAL variable and should be set with SET GLOBAL
+set @@session.innodb_trx_rseg_n_slots_debug='some';
+ERROR HY000: Variable 'innodb_trx_rseg_n_slots_debug' is a GLOBAL variable and should be set with SET GLOBAL
+set global innodb_trx_rseg_n_slots_debug=1.1;
+ERROR 42000: Incorrect argument type to variable 'innodb_trx_rseg_n_slots_debug'
+set global innodb_trx_rseg_n_slots_debug='foo';
+ERROR 42000: Incorrect argument type to variable 'innodb_trx_rseg_n_slots_debug'
+set global innodb_trx_rseg_n_slots_debug=-2;
+Warnings:
+Warning	1292	Truncated incorrect innodb_trx_rseg_n_slots_debug value: '-2'
+set global innodb_trx_rseg_n_slots_debug=1e1;
+ERROR 42000: Incorrect argument type to variable 'innodb_trx_rseg_n_slots_debug'
+set global innodb_trx_rseg_n_slots_debug=1024;
+set global innodb_trx_rseg_n_slots_debug=1025;
+Warnings:
+Warning	1292	Truncated incorrect innodb_trx_rseg_n_slots_debug value: '1025'
+SET @@global.innodb_trx_rseg_n_slots_debug = @start_global_value;
+SELECT @@global.innodb_trx_rseg_n_slots_debug;
+@@global.innodb_trx_rseg_n_slots_debug
+0

mysql-test/suite/sys_vars/r/plugin_dir_basic.result

 select @@global.plugin_dir;
 @@global.plugin_dir
-MYSQL_TMP_DIR
+MYSQL_TMP_DIR/
 select @@session.plugin_dir;
 ERROR HY000: Variable 'plugin_dir' is a GLOBAL variable
 show global variables like 'plugin_dir';
 Variable_name	Value
-plugin_dir	MYSQL_TMP_DIR
+plugin_dir	MYSQL_TMP_DIR/
 show session variables like 'plugin_dir';
 Variable_name	Value
-plugin_dir	MYSQL_TMP_DIR
+plugin_dir	MYSQL_TMP_DIR/
 select * from information_schema.global_variables where variable_name='plugin_dir';
 VARIABLE_NAME	VARIABLE_VALUE
-PLUGIN_DIR	MYSQL_TMP_DIR
+PLUGIN_DIR	MYSQL_TMP_DIR/
 select * from information_schema.session_variables where variable_name='plugin_dir';
 VARIABLE_NAME	VARIABLE_VALUE
-PLUGIN_DIR	MYSQL_TMP_DIR
+PLUGIN_DIR	MYSQL_TMP_DIR/
 set global plugin_dir=1;
 ERROR HY000: Variable 'plugin_dir' is a read only variable
 set session plugin_dir=1;

mysql-test/suite/sys_vars/t/all_vars.test

@@ -47,10 +47,6 @@ eval load data infile "$MYSQLTEST_VARDIR/tmp/sys_vars.all_vars.txt" into table t
 insert into t2 select variable_name from information_schema.global_variables;
 insert into t2 select variable_name from information_schema.session_variables;
 
-# This is only present in debug builds.
-delete from t2 where variable_name='innodb_change_buffering_debug';
-delete from t2 where variable_name='innodb_trx_rseg_n_slots_debug';
-
 # Performance schema variables are too long for files named
 # 'mysql-test/suite/sys_vars/t/' ...
 # ... 'performance_schema_events_waits_history_long_size_basic-master.opt'

mysql-test/suite/sys_vars/t/character_sets_dir_basic.test

 #
 # show the global and session values;
 #
---replace_result $MYSQL_CHARSETSDIR MYSQL_CHARSETSDIR
+
+# workaround to adjust for the directory separators being different in 
+# different OSes : slash on unixes and backslash or slash on windows.
+# TODO: fix with a proper comparison in mysqltest
+let $rcd= `SELECT REPLACE('$MYSQL_CHARSETSDIR', '\\\\\', '.')`;
+let $rcd= `SELECT REPLACE('$rcd', '/', '.')`;
+let $regex_charsetdir= `SELECT '/$rcd[\\\\\/\\\\\]/MYSQL_CHARSETSDIR/'`;
+
+--replace_regex $regex_charsetdir
 select @@global.character_sets_dir;
+
 --error ER_INCORRECT_GLOBAL_LOCAL_VAR
 select @@session.character_sets_dir;
---replace_result $MYSQL_CHARSETSDIR MYSQL_CHARSETSDIR
+--replace_regex $regex_charsetdir
 show global variables like 'character_sets_dir';
---replace_result $MYSQL_CHARSETSDIR MYSQL_CHARSETSDIR
+--replace_regex $regex_charsetdir
 show session variables like 'character_sets_dir';
---replace_result $MYSQL_CHARSETSDIR MYSQL_CHARSETSDIR
+--replace_regex $regex_charsetdir
 select * from information_schema.global_variables where variable_name='character_sets_dir';
---replace_result $MYSQL_CHARSETSDIR MYSQL_CHARSETSDIR
+--replace_regex $regex_charsetdir
 select * from information_schema.session_variables where variable_name='character_sets_dir';
 
 #

mysql-test/suite/sys_vars/t/innodb_change_buffering_debug_basic.test

+--source include/have_innodb.inc
+--source include/have_debug.inc
+
+SET @start_global_value = @@global.innodb_change_buffering_debug;
+SELECT @start_global_value;
+
+#
+# exists as global only
+#
+select @@global.innodb_change_buffering_debug in (0, 1);
+select @@global.innodb_change_buffering_debug;
+--error ER_INCORRECT_GLOBAL_LOCAL_VAR
+select @@session.innodb_change_buffering_debug;
+show global variables like 'innodb_change_buffering_debug';
+show session variables like 'innodb_change_buffering_debug';
+select * from information_schema.global_variables where variable_name='innodb_change_buffering_debug';
+select * from information_schema.session_variables where variable_name='innodb_change_buffering_debug';
+
+#
+# show that it's writable
+#
+set global innodb_change_buffering_debug=1;
+select @@global.innodb_change_buffering_debug;
+select * from information_schema.global_variables where variable_name='innodb_change_buffering_debug';
+select * from information_schema.session_variables where variable_name='innodb_change_buffering_debug';
+set @@global.innodb_change_buffering_debug=0;
+select @@global.innodb_change_buffering_debug;
+select * from information_schema.global_variables where variable_name='innodb_change_buffering_debug';
+select * from information_schema.session_variables where variable_name='innodb_change_buffering_debug';
+--error ER_GLOBAL_VARIABLE
+set session innodb_change_buffering_debug='some';
+--error ER_GLOBAL_VARIABLE
+set @@session.innodb_change_buffering_debug='some';
+
+#
+# incorrect types
+#
+--error ER_WRONG_TYPE_FOR_VAR
+set global innodb_change_buffering_debug=1.1;
+--error ER_WRONG_TYPE_FOR_VAR
+set global innodb_change_buffering_debug='foo';
+set global innodb_change_buffering_debug=-2;
+--error ER_WRONG_TYPE_FOR_VAR
+set global innodb_change_buffering_debug=1e1;
+set global innodb_change_buffering_debug=2;
+
+#
+# Cleanup
+#
+
+SET @@global.innodb_change_buffering_debug = @start_global_value;
+SELECT @@global.innodb_change_buffering_debug;

mysql-test/suite/sys_vars/t/innodb_trx_rseg_n_slots_debug_basic.test

+--source include/have_innodb.inc
+--source include/have_debug.inc
+
+SET @start_global_value = @@global.innodb_trx_rseg_n_slots_debug;
+SELECT @start_global_value;
+
+#
+# exists as global only
+#
+select @@global.innodb_trx_rseg_n_slots_debug between 0 and 1024;
+select @@global.innodb_trx_rseg_n_slots_debug;
+--error ER_INCORRECT_GLOBAL_LOCAL_VAR
+select @@session.innodb_trx_rseg_n_slots_debug;
+show global variables like 'innodb_trx_rseg_n_slots_debug';
+show session variables like 'innodb_trx_rseg_n_slots_debug';
+select * from information_schema.global_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+select * from information_schema.session_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+
+#
+# show that it's writable
+#
+set global innodb_trx_rseg_n_slots_debug=1;
+select @@global.innodb_trx_rseg_n_slots_debug;
+select * from information_schema.global_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+select * from information_schema.session_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+set @@global.innodb_trx_rseg_n_slots_debug=0;
+select @@global.innodb_trx_rseg_n_slots_debug;
+select * from information_schema.global_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+select * from information_schema.session_variables where variable_name='innodb_trx_rseg_n_slots_debug';
+--error ER_GLOBAL_VARIABLE
+set session innodb_trx_rseg_n_slots_debug='some';
+--error ER_GLOBAL_VARIABLE
+set @@session.innodb_trx_rseg_n_slots_debug='some';
+
+#
+# incorrect types
+#
+--error ER_WRONG_TYPE_FOR_VAR
+set global innodb_trx_rseg_n_slots_debug=1.1;
+--error ER_WRONG_TYPE_FOR_VAR
+set global innodb_trx_rseg_n_slots_debug='foo';
+set global innodb_trx_rseg_n_slots_debug=-2;
+--error ER_WRONG_TYPE_FOR_VAR
+set global innodb_trx_rseg_n_slots_debug=1e1;
+set global innodb_trx_rseg_n_slots_debug=1024;
+set global innodb_trx_rseg_n_slots_debug=1025;
+
+#
+# Cleanup
+#
+
+SET @@global.innodb_trx_rseg_n_slots_debug = @start_global_value;
+SELECT @@global.innodb_trx_rseg_n_slots_debug;

scripts/mysqld_safe.sh

@@ -740,17 +740,55 @@ cmd="$cmd $args"
 test -n "$NOHUP_NICENESS" && cmd="$cmd < /dev/null"
 
 log_notice "Starting $MYSQLD daemon with databases from $DATADIR"
+
+# variable to track the current number of "fast" (a.k.a. subsecond) restarts
+fast_restart=0
+# maximum number of restarts before trottling kicks in
+max_fast_restarts=5
+# flag whether a usable sleep command exists
+have_sleep=1
+
 while true
 do
   rm -f $safe_mysql_unix_port "$pid_file"	# Some extra safety
 
+  start_time=`date +%M%S`
+
   eval_log_error "$cmd"
 
+  end_time=`date +%M%S`
+
   if test ! -f "$pid_file"		# This is removed if normal shutdown
   then
     break
   fi
 
+
+  # sanity check if time reading is sane and there's sleep
+  if test $end_time -gt 0 -a $have_sleep -gt 0
+  then
+    # throttle down the fast restarts
+    if test $end_time -eq $start_time
+    then
+      fast_restart=`expr $fast_restart + 1`
+      if test $fast_restart -ge $max_fast_restarts
+      then
+        log_notice "The server is respawning too fast. Sleeping for 1 second."
+        sleep 1
+        sleep_state=$?
+        if test $sleep_state -gt 0
+        then
+          log_notice "The server is respawning too fast and no working sleep command. Turning off trottling."
+          have_sleep=0
+        fi
+
+        fast_restart=0
+      fi
+    else
+      fast_restart=0
+    fi
+  fi
+
   if @TARGET_LINUX@ && test $KILL_MYSQLD -eq 1
   then
     # Test if one process was hanging.

sql/mysqld.cc

@@ -7476,8 +7476,10 @@ static int fix_paths(void)
   (void) my_load_path(mysql_home,mysql_home,""); // Resolve current dir
   (void) my_load_path(mysql_real_data_home,mysql_real_data_home,mysql_home);
   (void) my_load_path(pidfile_name, pidfile_name_ptr, mysql_real_data_home);
-  (void) my_load_path(opt_plugin_dir, opt_plugin_dir_ptr ? opt_plugin_dir_ptr :
-                                      get_relative_path(PLUGINDIR), mysql_home);
+
+  convert_dirname(opt_plugin_dir, opt_plugin_dir_ptr ? opt_plugin_dir_ptr : 
+                                  get_relative_path(PLUGINDIR), NullS);
+  (void) my_load_path(opt_plugin_dir, opt_plugin_dir, mysql_home);
   opt_plugin_dir_ptr= opt_plugin_dir;
 
   my_realpath(mysql_unpacked_real_data_home, mysql_real_data_home, MYF(0));

sql/sql_plugin.cc

@@ -463,18 +463,22 @@ static st_plugin_dl *plugin_dl_add(const LEX_STRING *dl, int report)
   dlpathlen=
     strxnmov(dlpath, sizeof(dlpath) - 1, opt_plugin_dir, "/", dl->str, NullS) -
     dlpath;
+  (void) unpack_filename(dlpath, dlpath);
   plugin_dl.ref_count= 1;
   /* Open new dll handle */
   if (!(plugin_dl.handle= dlopen(dlpath, RTLD_NOW)))
   {
-    const char *errmsg=dlerror();
+    const char *errmsg;
+    int error_number= dlopen_errno;
+    DLERROR_GENERATE(errmsg, error_number);
+
     if (!strncmp(dlpath, errmsg, dlpathlen))
     { // if errmsg starts from dlpath, trim this prefix.
       errmsg+=dlpathlen;
       if (*errmsg == ':') errmsg++;
       if (*errmsg == ' ') errmsg++;
     }
-    report_error(report, ER_CANT_OPEN_LIBRARY, dlpath, errno, errmsg);
+    report_error(report, ER_CANT_OPEN_LIBRARY, dlpath, error_number, errmsg);
     DBUG_RETURN(0);
   }
   /* Determine interface version */

sql/sql_udf.cc

@@ -221,10 +221,15 @@ void udf_init()
       char dlpath[FN_REFLEN];
       strxnmov(dlpath, sizeof(dlpath) - 1, opt_plugin_dir, "/", tmp->dl,
                NullS);
+      (void) unpack_filename(dlpath, dlpath);
       if (!(dl= dlopen(dlpath, RTLD_NOW)))
       {
+	const char *errmsg;
+	int error_number= dlopen_errno;
+	DLERROR_GENERATE(errmsg, error_number);
+
 	/* Print warning to log */
-        sql_print_error(ER(ER_CANT_OPEN_LIBRARY), tmp->dl, errno, dlerror());
+        sql_print_error(ER(ER_CANT_OPEN_LIBRARY), tmp->dl, error_number, errmsg);
 	/* Keep the udf in the hash so that we can remove it later */
 	continue;
       }
@@ -469,12 +474,18 @@ int mysql_create_function(THD *thd,udf_func *udf)
   {
     char dlpath[FN_REFLEN];
     strxnmov(dlpath, sizeof(dlpath) - 1, opt_plugin_dir, "/", udf->dl, NullS);
+    (void) unpack_filename(dlpath, dlpath);
+
     if (!(dl = dlopen(dlpath, RTLD_NOW)))
     {
+      const char *errmsg;
+      int error_number= dlopen_errno;
+      DLERROR_GENERATE(errmsg, error_number);
+
       DBUG_PRINT("error",("dlopen of %s failed, error: %d (%s)",
-                          udf->dl, errno, dlerror()));
+                          udf->dl, error_number, errmsg));
       my_error(ER_CANT_OPEN_LIBRARY, MYF(0),
-               udf->dl, errno, dlerror());
+               udf->dl, error_number, errmsg);
       goto err;
     }
     new_dl=1;