BUG# 13052

Clean application of patch - 
- Added --tz-utc to fix issue of dumping timestamp values between 
servers with different global time zone settings, particularly 
with regard to the day of DST changeover, which without this fix,
 would dump duplicate timestamp values.


client/client_priv.h:
  BUG# 13052 - clean application of http://lists.mysql.com/internals/30993
client/mysqldump.c:
  BUG# 13052
  
  Clean application of patch http://lists.mysql.com/internals/30993
  
  - added new --tz-utc option
  - added saving of TIME_ZONE in dump file
  - set TIME_ZONE to "+00:00" in dump
mysql-test/r/mysqldump.result:
  BUG# 13052 New results
mysql-test/t/mysqldump.test:
  BUG# 13052
  
  Added new test to test if the new option --tz-utc places 
  'SET TIME_ZONE="+00:00" at the top of the file and that this fixes 
  the problem of ending up with duplicate timestamp values that should
   be unique on eve of DST

client/client_priv.h

@@ -51,5 +51,5 @@ enum options_client
 #endif
   OPT_TRIGGERS,
   OPT_IGNORE_TABLE,OPT_INSERT_IGNORE,OPT_SHOW_WARNINGS,OPT_DROP_DATABASE,
-  OPT_AUTO_CLOSE
+  OPT_TZ_UTC, OPT_AUTO_CLOSE
 };

client/mysqldump.c

@@ -92,7 +92,7 @@ static my_bool  verbose=0,tFlag=0,dFlag=0,quick= 1, extended_insert= 1,
 		opt_single_transaction=0, opt_comments= 0, opt_compact= 0,
 		opt_hex_blob=0, opt_order_by_primary=0, opt_ignore=0,
                 opt_complete_insert= 0, opt_drop_database= 0,
-                opt_dump_triggers= 0, opt_routines=0;
+                opt_dump_triggers= 0, opt_routines=0, opt_tz_utc=1;
 static ulong opt_max_allowed_packet, opt_net_buffer_length;
 static MYSQL mysql_connection,*sock=0;
 static my_bool insert_pat_inited=0;
@@ -385,6 +385,9 @@ static struct my_option my_long_options[] =
    {"triggers", OPT_TRIGGERS, "Dump triggers for each dumped table",
      (gptr*) &opt_dump_triggers, (gptr*) &opt_dump_triggers, 0, GET_BOOL,
      NO_ARG, 1, 0, 0, 0, 0, 0},
+  {"tz-utc", OPT_TZ_UTC,
+    "SET TIME_ZONE='UTC' at top of dump to allow dumping of date types between servers with different time zones.",
+    (gptr*) &opt_tz_utc, (gptr*) &opt_tz_utc, 0, GET_BOOL, NO_ARG, 1, 0, 0, 0, 0, 0},
 #ifndef DONT_ALLOW_USER_CHANGE
   {"user", 'u', "User for login if not current user.",
    (gptr*) &current_user, (gptr*) &current_user, 0, GET_STR, REQUIRED_ARG,
@@ -509,6 +512,13 @@ static void write_header(FILE *sql_file, char *db_name)
 "\n/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;"
 "\n/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;"
 "\n/*!40101 SET NAMES %s */;\n",default_charset);
+
+    if (opt_tz_utc)
+    {
+      fprintf(sql_file, "/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;\n");
+      fprintf(sql_file, "/*!40103 SET TIME_ZONE='+00:00' */;\n");
+    }
+
     if (!path)
     {
       fprintf(md_result_file,"\
@@ -535,6 +545,9 @@ static void write_footer(FILE *sql_file)
   }
   else if (!opt_compact)
   {
+    if (opt_tz_utc)
+      fprintf(sql_file,"/*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */;\n");
+
     fprintf(sql_file,"\n/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;\n");
     if (!path)
     {
@@ -902,6 +915,20 @@ static int dbConnect(char *host, char *user,char *passwd)
     safe_exit(EX_MYSQLERR);
     return 1;
   }
+  /*
+    set time_zone to UTC to allow dumping date types between servers with 
+    different time zone settings
+  */
+  if (opt_tz_utc)
+  {
+    my_snprintf(buff, sizeof(buff), "/*!40103 SET TIME_ZONE='+00:00' */");
+    if (mysql_query_with_error_report(sock, 0, buff))
+    {
+      mysql_close(sock);
+      safe_exit(EX_MYSQLERR);
+      return 1;
+    }
+  }
   return 0;
 } /* dbConnect */
 

mysql-test/t/mysqldump.test

@@ -907,3 +907,24 @@ DROP PROCEDURE bug9056_proc1;
 DROP PROCEDURE bug9056_proc2;
 drop table t1;
 
+#
+# BUG# 13052 - mysqldump timestamp reloads broken
+#
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+
+create table t1 (`d` timestamp, unique (`d`));
+set time_zone='+00:00';
+insert into t1 values ('2003-10-25 22:00:00'),('2003-10-25 23:00:00');
+# results should show two different time values
+select * from t1;
+set time_zone='Europe/Moscow';
+# results should show two same time values, despite unique
+select * from t1;
+set global time_zone='Europe/Moscow';
+--exec $MYSQL_DUMP --skip-comments --databases test
+--exec $MYSQL_DUMP --skip-tz-utc --skip-comments --databases test
+drop table t1;
+set global time_zone=default;
+set time_zone=default;