Merge from 5.1

mysql-test/r/ctype_cp1250_ch.result

@@ -238,3 +238,6 @@ select a from t1 where a like "abcdefgh
 a
 abcdefgh
 drop table t1;
+set global LC_MESSAGES=convert((@@global.log_bin_trust_function_creators) 
+using cp1250);
+ERROR HY000: Unknown locale: '1'

mysql-test/r/ctype_cp1251.result

@@ -386,6 +386,8 @@ FD	FD	FD	D18D	FD
 FE	FE	FE	D18E	FE	
 FF	FF	FF	D18F	FF	
 DROP TABLE t1;
+set global LC_TIME_NAMES=convert((-8388608) using cp1251);
+ERROR HY000: Unknown locale: '-8388608'
 #
 # End of 5.1 tests
 #

mysql-test/r/ctype_eucjpms.result

@@ -9859,6 +9859,8 @@ hex(convert(_eucjpms 0xA5FE41 using ucs2))
 select hex(convert(_eucjpms 0x8FABF841 using ucs2));
 hex(convert(_eucjpms 0x8FABF841 using ucs2))
 003F0041
+set global LC_TIME_NAMES=convert((convert((0x63) using eucjpms)) using utf8);
+ERROR HY000: Unknown locale: 'c'
 #
 # Start of 5.5 tests
 #

mysql-test/t/ctype_cp1250_ch.test

@@ -72,3 +72,13 @@ select a from t1 where a like "abcdefgh
 drop table t1;
 
 # End of 4.1 tests
+
+#
+# Bug #48053 String::c_ptr has a race and/or does an invalid 
+#            memory reference
+#            (triggered by Valgrind tests)
+#  (see also ctype_eucjpms.test, ctype_cp1250.test, ctype_cp1251.test)
+#
+--error 1649
+set global LC_MESSAGES=convert((@@global.log_bin_trust_function_creators) 
+    using cp1250);

mysql-test/t/ctype_cp1251.test

@@ -65,6 +65,16 @@ DROP TABLE t1;
 
 --source include/ctype_8bit.inc
 
+#
+# Bug #48053 String::c_ptr has a race and/or does an invalid 
+#            memory reference
+#            (triggered by Valgrind tests)
+#  (see also ctype_eucjpms.test, ctype_cp1250.test, ctype_cp1251.test)
+#
+--error 1649
+set global LC_TIME_NAMES=convert((-8388608) using cp1251);
+
+
 --echo #
 --echo # End of 5.1 tests
 --echo #

mysql-test/t/ctype_eucjpms.test

@@ -382,6 +382,16 @@ select hex(convert(_eucjpms 0xA5FE41 using ucs2));
 select hex(convert(_eucjpms 0x8FABF841 using ucs2));
 
 
+#
+# Bug #48053 String::c_ptr has a race and/or does an invalid 
+#            memory reference
+#            (triggered by Valgrind tests)
+#  (see also ctype_eucjpms.test, ctype_cp1250.test, ctype_cp1251.test)
+#
+--error 1649
+set global LC_TIME_NAMES=convert((convert((0x63) using eucjpms)) using utf8);
+
+
 --echo #
 --echo # Start of 5.5 tests
 --echo #

sql/sql_string.h

@@ -113,6 +113,9 @@ class String
   inline const char *ptr() const { return Ptr; }
   inline char *c_ptr()
   {
+    DBUG_ASSERT(!alloced || !Ptr || !Alloced_length || 
+                (Alloced_length >= (str_length + 1)));
+
     if (!Ptr || Ptr[str_length])		/* Should be safe */
       (void) realloc(str_length);
     return Ptr;

sql/sys_vars.cc

@@ -3082,7 +3082,7 @@ static bool check_locale(sys_var *self, THD *thd, set_var *var)
     String str(buff, sizeof(buff), system_charset_info), *res;
     if (!(res=var->value->val_str(&str)))
       return true;
-    else if (!(locale= my_locale_by_name(res->c_ptr())))
+    else if (!(locale= my_locale_by_name(res->c_ptr_safe())))
     {
       ErrConvString err(res);
       my_error(ER_UNKNOWN_LOCALE, MYF(0), err.ptr());