Merge tnurnberg@bk-internal.mysql.com:/home/bk/mysql-5.1-maint

into  salvation.intern.azundris.com:/home/tnurnberg/21913/my51-21913

mysql-test/r/func_time.result

@@ -911,6 +911,18 @@ union
 (select time_format(timediff(now(), DATE_SUB(now(),INTERVAL 5 HOUR)),'%k') As H);
 H
 5
+SET NAMES latin1;
+SET character_set_results = NULL;
+SHOW VARIABLES LIKE 'character_set_results';
+Variable_name	Value
+character_set_results	
+CREATE TABLE testBug8868 (field1 DATE, field2 VARCHAR(32) CHARACTER SET BINARY);
+INSERT INTO testBug8868 VALUES ('2006-09-04', 'abcd');
+SELECT DATE_FORMAT(field1,'%b-%e %l:%i%p') as fmtddate, field2 FROM testBug8868;
+fmtddate	field2
+Sep-4 12:00AM	abcd
+DROP TABLE testBug8868;
+SET NAMES DEFAULT;
 End of 4.1 tests
 explain extended select timestampdiff(SQL_TSI_WEEK, '2001-02-01', '2001-05-01') as a1,
 timestampdiff(SQL_TSI_FRAC_SECOND, '2001-02-01 12:59:59.120000', '2001-05-01 12:58:58.119999') as a2;

mysql-test/t/func_time.test

@@ -464,6 +464,24 @@ union
 union
 (select time_format(timediff(now(), DATE_SUB(now(),INTERVAL 5 HOUR)),'%k') As H);
 
+#
+# 21913: DATE_FORMAT() Crashes mysql server if I use it through
+#        mysql-connector-j driver.
+#
+
+SET NAMES latin1;
+SET character_set_results = NULL;
+SHOW VARIABLES LIKE 'character_set_results';
+
+CREATE TABLE testBug8868 (field1 DATE, field2 VARCHAR(32) CHARACTER SET BINARY);
+INSERT INTO testBug8868 VALUES ('2006-09-04', 'abcd');
+
+SELECT DATE_FORMAT(field1,'%b-%e %l:%i%p') as fmtddate, field2 FROM testBug8868;
+
+DROP TABLE testBug8868;
+
+SET NAMES DEFAULT;
+
 --echo End of 4.1 tests
 
 explain extended select timestampdiff(SQL_TSI_WEEK, '2001-02-01', '2001-05-01') as a1,

sql/sql_string.cc

@@ -238,6 +238,10 @@ bool String::copy(const char *str,uint32 arg_length, CHARSET_INFO *cs)
    0  No conversion needed
    1  Either character set conversion or adding leading  zeros
       (e.g. for UCS-2) must be done
+
+  NOTE
+  to_cs may be NULL for "no conversion" if the system variable
+  character_set_results is NULL.
 */
 
 bool String::needs_conversion(uint32 arg_length,
@@ -246,7 +250,8 @@ bool String::needs_conversion(uint32 arg_length,
 			      uint32 *offset)
 {
   *offset= 0;
-  if ((to_cs == &my_charset_bin) || 
+  if (!to_cs ||
+      (to_cs == &my_charset_bin) || 
       (to_cs == from_cs) ||
       my_charset_same(from_cs, to_cs) ||
       ((from_cs == &my_charset_bin) &&