MDEV-31684 Add timezone information to DATE_FORMAT

Before starting to go over the format string, prepare the current time
zone information incase '%z' or '%Z' is encountered.
This information can be obtained as given below:

A) If timezone is not set ( meaning we are working with system timezone):
Get the MYSQL_TIME representation for current time and GMT time using
current thread variable for timezone and timezone variable for UTC
respectively. This MYSQL_TIME variable will be used to calculate time
difference. Also convert current time in second to tm structure to
get system timezone information.

B) If timezone is set as offset:
Get timezone information using current timezone information and store
in appropriate variable.

C) If timezone is set as some place (example: Europe/Berlin)
Get timezone information by searching the timezone. During internal
timezone search, information like timeoffset from UTC and abbrevation
is stored in another relevant structure. Hence use the same information.

mysql-test/main/date_formats.result

@@ -555,3 +555,49 @@ time_format('01 02:02:02', '%T')
 select time_format('2001-01-01 02:02:02', '%T');
 time_format('2001-01-01 02:02:02', '%T')
 02:02:02
+#
+# Beginning of 11.3 test
+#
+# MDEV-31684: Add timezone information to DATE_FORMAT
+#
+SET @old_timezone= @@time_zone;
+# Using named timezones
+SET TIME_ZONE='Japan';
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+current_timezone
++0900 JST
+SET @@time_zone='Europe/Moscow';
+SELECT DATE_FORMAT('1965-02-17 22:23:00', '%z %Z') AS current_timezone;
+current_timezone
++0300 MSK
+SELECT DATE_FORMAT('1965-12-31 22:23:00', '%z %Z') AS current_timezone;
+current_timezone
++0300 MSK
+SELECT DATE_FORMAT('1985-06-01', '%z %Z');
+DATE_FORMAT('1985-06-01', '%z %Z')
++0400 MSD
+# Using positive and negative offset
+SET TIME_ZONE= '-05:30';
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+current_timezone
+-0530 -05:30
+SET TIME_ZONE= '+04:30';
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+current_timezone
++0430 +04:30
+# Using UTC
+SET TIME_ZONE='UTC';
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+current_timezone
++0000 UTC
+# using system time
+#
+# output depends on system time information. Hence replacing
+# to avoid result diff test failures.
+#
+SET @@time_zone= default;
+SELECT DATE_FORMAT('2009-10+|-HH:MM ABC22:23:00', '%z %Z') AS current_timezone;
+current_timezone
++|-HH:MM ABC
+SET @@time_zone= @old_timezone;
+# End of 11.3 test

mysql-test/main/date_formats.test

@@ -256,3 +256,51 @@ select time_format('2001-01-01 02:02:02', '%d %T');
 select time_format('01 02:02:02', '%d %T');
 select time_format('01 02:02:02', '%T');
 select time_format('2001-01-01 02:02:02', '%T');
+
+--echo #
+--echo # Beginning of 11.3 test
+--echo #
+--echo # MDEV-31684: Add timezone information to DATE_FORMAT
+--echo #
+
+SET @old_timezone= @@time_zone;
+
+
+--echo # Using named timezones
+
+SET TIME_ZONE='Japan';
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+
+SET @@time_zone='Europe/Moscow';
+SELECT DATE_FORMAT('1965-02-17 22:23:00', '%z %Z') AS current_timezone;
+SELECT DATE_FORMAT('1965-12-31 22:23:00', '%z %Z') AS current_timezone;
+SELECT DATE_FORMAT('1985-06-01', '%z %Z');
+
+--echo # Using positive and negative offset
+
+SET TIME_ZONE= '-05:30';
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+
+SET TIME_ZONE= '+04:30';
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+
+
+--echo # Using UTC
+
+SET TIME_ZONE='UTC';
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+
+--echo # using system time
+--echo #
+--echo # output depends on system time information. Hence replacing
+--echo # to avoid result diff test failures.
+--echo #
+
+SET @@time_zone= default;
+
+--replace_regex /[+-][0-9]* [A-Z]*/+|-HH:MM ABC/
+SELECT DATE_FORMAT('2009-10-04 22:23:00', '%z %Z') AS current_timezone;
+
+SET @@time_zone= @old_timezone;
+
+--echo # End of 11.3 test

mysql-test/main/mysqldump-system,win.rdiff

@@ -3,24 +3,24 @@
 @@ -449,9 +449,9 @@
  Table	Checksum
  mysql.roles_mapping	2510045525
- mysql.time_zone_transition	3895294076
+ mysql.time_zone_transition	3719776009
 -mysql.plugin	1587119305
 +mysql.plugin	2184891911
  mysql.servers	2079085450
 -mysql.func	3241572444
 +mysql.func	310494789
- mysql.innodb_table_stats	347867921
- mysql.table_stats	664320059
+ mysql.innodb_table_stats	1285726777
+ mysql.table_stats	2836905944
  # Opps....
 @@ -484,9 +484,9 @@
  Table	Checksum
  mysql.roles_mapping	2510045525
- mysql.time_zone_transition	3895294076
+ mysql.time_zone_transition	3719776009
 -mysql.plugin	1587119305
 +mysql.plugin	2184891911
  mysql.servers	2079085450
 -mysql.func	3241572444
 +mysql.func	310494789
- mysql.innodb_table_stats	347867921
- mysql.table_stats	664320059
+ mysql.innodb_table_stats	1285726777
+ mysql.table_stats	2836905944
  DROP FUNCTION IF EXISTS metaphon;

mysql-test/suite/funcs_1/r/is_tables_mysql.result

@@ -623,7 +623,7 @@ DATA_LENGTH	#DL#
 MAX_DATA_LENGTH	#MDL#
 INDEX_LENGTH	#IL#
 DATA_FREE	#DF#
-AUTO_INCREMENT	6
+AUTO_INCREMENT	7
 CREATE_TIME	#CRT#
 UPDATE_TIME	#UT#
 CHECK_TIME	#CT#

mysql-test/suite/funcs_1/r/is_tables_mysql_embedded.result

@@ -623,7 +623,7 @@ DATA_LENGTH	#DL#
 MAX_DATA_LENGTH	#MDL#
 INDEX_LENGTH	#IL#
 DATA_FREE	#DF#
-AUTO_INCREMENT	6
+AUTO_INCREMENT	7
 CREATE_TIME	#CRT#
 UPDATE_TIME	#UT#
 CHECK_TIME	#CT#
@@ -1412,7 +1412,7 @@ DATA_LENGTH	#DL#
 MAX_DATA_LENGTH	#MDL#
 INDEX_LENGTH	#IL#
 DATA_FREE	#DF#
-AUTO_INCREMENT	6
+AUTO_INCREMENT	7
 CREATE_TIME	#CRT#
 UPDATE_TIME	#UT#
 CHECK_TIME	#CT#

sql/item_timefunc.cc

@@ -473,15 +473,24 @@ static bool extract_date_time(THD *thd, DATE_TIME_FORMAT *format,
   Create a formatted date/time value in a string.
 */
 
-static bool make_date_time(const String *format, const MYSQL_TIME *l_time,
-                           timestamp_type type, const MY_LOCALE *locale,
-                           String *str)
+static bool make_date_time(THD *thd, const String *format,
+                           const MYSQL_TIME *l_time, timestamp_type type,
+                           const MY_LOCALE *locale, String *str)
 {
   char intbuff[15];
   uint hours_i;
   uint weekday;
   ulong length;
   const char *ptr, *end;
+  int diff_hr=0, diff_min=0;
+  char abbrevation[8];
+  struct tz tmp;
+  tmp.is_inited= false;
+
+  Time_zone* curr_timezone= my_tz_find(thd,
+                               thd->variables.time_zone->get_name());
+  memset(abbrevation, 0, sizeof(abbrevation));
+
 
   str->length(0);
 
@@ -699,6 +708,44 @@ static bool make_date_time(const String *format, const MYSQL_TIME *l_time,
 	str->append_with_prefill(intbuff, length, 1, '0');
 	break;
 
+      case 'z':
+      {
+        if (!tmp.is_inited)
+        {
+          curr_timezone->get_timezone_information(&tmp, l_time);
+          tmp.is_inited= true;
+        }
+        ulonglong seconds= abs(tmp.seconds_offset);
+        diff_hr= (int)(seconds/3600L);
+        int temp= (int)(seconds%3600L);
+        diff_min= temp/60L;
+
+        if (tmp.is_behind)
+          str->append("-", 1);
+        else
+          str->append("+", 1);
+
+        if (diff_hr/10 == 0)
+          str->append("0", 1);
+        length= (uint) (int10_to_str(diff_hr, intbuff, 10) - intbuff);
+        str->append(intbuff, length);
+        if (diff_min/10 == 0)
+          str->append("0", 1);
+        length= (uint) (int10_to_str(diff_min, intbuff, 10) - intbuff);
+        str->append(intbuff, length);
+      }
+        break;
+
+      case 'Z':
+      {
+        if (!tmp.is_inited)
+        {
+          curr_timezone->get_timezone_information(&tmp, l_time);
+          tmp.is_inited= true;
+        }
+        str->append(tmp.abbrevation, strlen(tmp.abbrevation));
+      }
+        break;
       default:
 	str->append(*ptr);
 	break;
@@ -1912,7 +1959,7 @@ String *Item_func_date_format::val_str(String *str)
 
   /* Create the result string */
   str->set_charset(collation.collation);
-  if (!make_date_time(format, &l_time,
+  if (!make_date_time(thd, format, &l_time,
                       is_time_format ? MYSQL_TIMESTAMP_TIME :
                                        MYSQL_TIMESTAMP_DATE,
                       lc, str))

sql/tztime.cc

@@ -55,15 +55,10 @@
 
 /*
   Now we don't use abbreviations in server but we will do this in future.
+  Edit: Started needing abbrevation in server as part of task MDEV-31684.
 */
-#if defined(TZINFO2SQL) || defined(TESTTIME)
-#define ABBR_ARE_USED
-#else
-#if !defined(DBUG_OFF)
-/* Let use abbreviations for debug purposes */
-#undef ABBR_ARE_USED
+#ifndef ABBR_ARE_USED
 #define  ABBR_ARE_USED
-#endif /* !defined(DBUG_OFF) */
 #endif /* defined(TZINFO2SQL) || defined(TESTTIME) */
 
 /* Structure describing local time type (e.g. Moscow summer time (MSD)) */
@@ -1031,6 +1026,7 @@ class Time_zone_system : public Time_zone
   virtual my_time_t TIME_to_gmt_sec(const MYSQL_TIME *t, uint *error_code) const;
   virtual void gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const;
   virtual const String * get_name() const;
+  virtual void get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const;
 };
 
 
@@ -1097,6 +1093,25 @@ Time_zone_system::gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const
   adjust_leap_second(tmp);
 }
 
+void
+Time_zone_system::get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const
+{
+  uint error;
+  struct tm tm_local_time;
+
+  time_t time_sec= this->TIME_to_gmt_sec(local_TIME,  &error);
+
+  localtime_r(&time_sec, &tm_local_time);
+# ifdef	__USE_MISC
+    int len= strlen((tm_local_time.tm_zone));
+     strmake(curr_tz->abbrevation, tm_local_time.tm_zone, sizeof(tm_local_time.tm_zone)-1);
+    curr_tz->abbrevation[len]= '\0';
+# endif
+    curr_tz->seconds_offset= tm_local_time.tm_gmtoff;
+    curr_tz->is_behind= tm_local_time.tm_gmtoff < 0;
+
+}
+
 
 /*
   Get name of time zone
@@ -1128,6 +1143,7 @@ class Time_zone_utc : public Time_zone
                                     uint *error_code) const;
   virtual void gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const;
   virtual const String * get_name() const;
+  virtual void get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const;
 };
 
 
@@ -1175,6 +1191,22 @@ Time_zone_utc::gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const
   adjust_leap_second(tmp);
 }
 
+void
+Time_zone_utc::get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const
+{
+  uint error;
+  struct tm tm_local_time;
+
+  time_t time_sec= this->TIME_to_gmt_sec(local_TIME,  &error);
+
+  localtime_r(&time_sec, &tm_local_time);
+# ifdef	__USE_MISC
+    strmake(curr_tz->abbrevation, "UTC", 3);
+# endif
+    curr_tz->seconds_offset= tm_local_time.tm_gmtoff;
+    curr_tz->is_behind= tm_local_time.tm_gmtoff < 0;
+}
+
 
 /*
   Get name of time zone
@@ -1210,6 +1242,7 @@ class Time_zone_db : public Time_zone
   virtual my_time_t TIME_to_gmt_sec(const MYSQL_TIME *t, uint *error_code) const;
   virtual void gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const;
   virtual const String * get_name() const;
+  virtual void get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const;
 private:
   TIME_ZONE_INFO *tz_info;
   const String *tz_name;
@@ -1280,6 +1313,24 @@ Time_zone_db::gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const
   adjust_leap_second(tmp);
 }
 
+void
+Time_zone_db::get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const
+{
+  uint error;
+  my_time_t sec_in_utc;
+  const TRAN_TYPE_INFO *ttisp;
+
+  /* Get seconds since epoch. */
+  sec_in_utc= this->TIME_to_gmt_sec(local_TIME, &error);
+  /* Get local timezone information. */
+  ttisp= find_transition_type(sec_in_utc, tz_info);
+
+  curr_tz->seconds_offset= ttisp->tt_gmtoff;
+  curr_tz->is_behind= tz_info->revtis->rt_offset < 0 ? true : false;
+
+  strmake(curr_tz->abbrevation, &(tz_info->chars[ttisp->tt_abbrind]), tz_info->charcnt-1);
+}
+
 
 /*
   Get name of time zone
@@ -1309,6 +1360,7 @@ class Time_zone_offset : public Time_zone
                                     uint *error_code) const;
   virtual void   gmt_sec_to_TIME(MYSQL_TIME *tmp, my_time_t t) const;
   virtual const String * get_name() const;
+  virtual void get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const;
   /*
     This have to be public because we want to be able to access it from
     my_offset_tzs_get_key() function
@@ -1434,6 +1486,15 @@ Time_zone_offset::get_name() const
   return &name;
 }
 
+void
+Time_zone_offset::get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const
+{
+  curr_tz->seconds_offset= offset;
+  const char *name= get_name()->ptr();
+  curr_tz->is_behind= name[0] == '+' ? false : true;
+  strmake(curr_tz->abbrevation, name, sizeof(curr_tz->abbrevation)-1);
+}
+
 
 static Time_zone_utc tz_UTC;
 static Time_zone_system tz_SYSTEM;
@@ -1881,6 +1942,7 @@ tz_load_from_open_tables(const String *tz_name, TABLE_LIST *tz_tables)
   */
   TIME_ZONE_INFO tmp_tz_info;
   memset(&tmp_tz_info, 0, sizeof(TIME_ZONE_INFO));
+  memset(ttis, 0, sizeof(ttis));
 
   DBUG_ENTER("tz_load_from_open_tables");
 

sql/tztime.h

@@ -38,6 +38,19 @@ class THD;
   Actual time zones which are specified by DB, or via offset 
   or use system functions are its descendants.
 */
+
+/*
+  Has only offset from UTC, bool value to denote if it is
+  ahead (+), behind(-) of UTC and abbrevation.
+*/
+struct tz
+{
+  long seconds_offset;
+  bool is_behind;
+  char abbrevation[8];
+  bool is_inited;
+};
+
 class Time_zone: public Sql_alloc 
 {
 public:
@@ -62,6 +75,8 @@ class Time_zone: public Sql_alloc
   */
   virtual const String * get_name() const = 0;
 
+  virtual void get_timezone_information(struct tz* curr_tz, const MYSQL_TIME *local_TIME) const = 0;
+
   /** 
     We need this only for surpressing warnings, objects of this type are
     allocated on MEM_ROOT and should not require destruction.