MDEV-452 Add full support for auto-initialized/updated timestamp and datetime

Generalized support for auto-updated and/or auto-initialized timestamp
and datetime columns. This patch is a reimplementation of MySQL's
"WL#5874: CURRENT_TIMESTAMP as DEFAULT for DATETIME columns". In order to
ease future merges, this implementation reused few function and variable
names from MySQL's patch, however the implementation is quite different.

TODO:
The only unresolved problem in this patch is the semantics of LOAD DATA for
TIMESTAMP and DATETIME columns in the cases when there are missing or NULL
columns. I couldn't fully comprehend the logic behind MySQL's behavior and
its relationship with their own documentation, so I left the results to be
more consistent with all other LOAD cases.

The problematic test cases can be seen by running the test file function_defaults,
and observing the test case differences. Those were left on purpose for discussion.

10 files changed, 0 insertions, 44 deletions

diff --git a/storage/archive/ha_archive.cc b/storage/archive/ha_archive.cc
index b21e0561322..396d5a21be5 100644
--- a/storage/archive/ha_archive.cc
+++ b/storage/archive/ha_archive.cc
@@ -905,8 +905,6 @@ int ha_archive::write_row(uchar *buf)
     DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE);
 
   ha_statistic_increment(&SSV::ha_write_count);
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-    table->timestamp_field->set_time();
   mysql_mutex_lock(&share->mutex);
 
   if (!share->archive_write_open)
diff --git a/storage/csv/ha_tina.cc b/storage/csv/ha_tina.cc
index d31e5ee8d89..ba731298d02 100644
--- a/storage/csv/ha_tina.cc
+++ b/storage/csv/ha_tina.cc
@@ -999,9 +999,6 @@ int ha_tina::write_row(uchar * buf)
 
   ha_statistic_increment(&SSV::ha_write_count);
 
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-    table->timestamp_field->set_time();
-
   size= encode_quote(buf);
 
   if (!share->tina_write_opened)
@@ -1064,9 +1061,6 @@ int ha_tina::update_row(const uchar * old_data, uchar * new_data)
 
   ha_statistic_increment(&SSV::ha_update_count);
 
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
-    table->timestamp_field->set_time();
-
   size= encode_quote(new_data);
 
   /*
diff --git a/storage/federated/ha_federated.cc b/storage/federated/ha_federated.cc
index 549001ab08b..18ba636c0e2 100644
--- a/storage/federated/ha_federated.cc
+++ b/storage/federated/ha_federated.cc
@@ -1849,8 +1849,6 @@ int ha_federated::write_row(uchar *buf)
   values_string.length(0);
   insert_field_value_string.length(0);
   ha_statistic_increment(&SSV::ha_write_count);
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-    table->timestamp_field->set_time();
 
   /*
     start both our field and field values strings
diff --git a/storage/federatedx/ha_federatedx.cc b/storage/federatedx/ha_federatedx.cc
index a10285a81aa..7f095a9b96e 100644
--- a/storage/federatedx/ha_federatedx.cc
+++ b/storage/federatedx/ha_federatedx.cc
@@ -1993,8 +1993,6 @@ int ha_federatedx::write_row(uchar *buf)
 
   values_string.length(0);
   insert_field_value_string.length(0);
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-    table->timestamp_field->set_time();
 
   /*
     start both our field and field values strings
diff --git a/storage/heap/ha_heap.cc b/storage/heap/ha_heap.cc
index 305a8cae720..b9eef0d155b 100644
--- a/storage/heap/ha_heap.cc
+++ b/storage/heap/ha_heap.cc
@@ -241,8 +241,6 @@ void ha_heap::update_key_stats()
 int ha_heap::write_row(uchar * buf)
 {
   int res;
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-    table->timestamp_field->set_time();
   if (table->next_number_field && buf == table->record[0])
   {
     if ((res= update_auto_increment()))
@@ -264,8 +262,6 @@ int ha_heap::write_row(uchar * buf)
 int ha_heap::update_row(const uchar * old_data, uchar * new_data)
 {
   int res;
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
-    table->timestamp_field->set_time();
   res= heap_update(file,old_data,new_data);
   if (!res && ++records_changed*HEAP_STATS_UPDATE_THRESHOLD > 
               file->s->records)
diff --git a/storage/innobase/handler/ha_innodb.cc b/storage/innobase/handler/ha_innodb.cc
index c7adc9a7671..62694df0422 100644
--- a/storage/innobase/handler/ha_innodb.cc
+++ b/storage/innobase/handler/ha_innodb.cc
@@ -5163,9 +5163,6 @@ ha_innobase::write_row(
 
 	ha_statistic_increment(&SSV::ha_write_count);
 
-	if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-		table->timestamp_field->set_time();
-
 	sql_command = thd_sql_command(user_thd);
 
 	if ((sql_command == SQLCOM_ALTER_TABLE
@@ -5573,9 +5570,6 @@ ha_innobase::update_row(
 
 	ha_statistic_increment(&SSV::ha_update_count);
 
-	if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
-		table->timestamp_field->set_time();
-
 	if (prebuilt->upd_node) {
 		uvect = prebuilt->upd_node->update;
 	} else {
diff --git a/storage/maria/ha_maria.cc b/storage/maria/ha_maria.cc
index 785fe5d8226..f8f3abc41a5 100644
--- a/storage/maria/ha_maria.cc
+++ b/storage/maria/ha_maria.cc
@@ -1248,10 +1248,6 @@ int ha_maria::close(void)
 
 int ha_maria::write_row(uchar * buf)
 {
-  /* If we have a timestamp column, update it to the current time */
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-    table->timestamp_field->set_time();
-
   /*
      If we have an auto_increment column and we are writing a changed row
      or a new row, then update the auto_increment value in the record.
@@ -2245,8 +2241,6 @@ bool ha_maria::is_crashed() const
 int ha_maria::update_row(const uchar * old_data, uchar * new_data)
 {
   CHECK_UNTIL_WE_FULLY_IMPLEMENTED_VERSIONING("UPDATE in WRITE CONCURRENT");
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
-    table->timestamp_field->set_time();
   return maria_update(file, old_data, new_data);
 }
 
diff --git a/storage/myisam/ha_myisam.cc b/storage/myisam/ha_myisam.cc
index 73e0fadd530..5f24a002014 100644
--- a/storage/myisam/ha_myisam.cc
+++ b/storage/myisam/ha_myisam.cc
@@ -832,10 +832,6 @@ int ha_myisam::close(void)
 
 int ha_myisam::write_row(uchar *buf)
 {
-  /* If we have a timestamp column, update it to the current time */
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-    table->timestamp_field->set_time();
-
   /*
     If we have an auto_increment column and we are writing a changed row
     or a new row, then update the auto_increment value in the record.
@@ -1656,8 +1652,6 @@ bool ha_myisam::is_crashed() const
 
 int ha_myisam::update_row(const uchar *old_data, uchar *new_data)
 {
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
-    table->timestamp_field->set_time();
   return mi_update(file,old_data,new_data);
 }
 
diff --git a/storage/myisammrg/ha_myisammrg.cc b/storage/myisammrg/ha_myisammrg.cc
index 47a3abb78d2..2c1e85ec9ff 100644
--- a/storage/myisammrg/ha_myisammrg.cc
+++ b/storage/myisammrg/ha_myisammrg.cc
@@ -1078,8 +1078,6 @@ int ha_myisammrg::write_row(uchar * buf)
   if (file->merge_insert_method == MERGE_INSERT_DISABLED || !file->tables)
     DBUG_RETURN(HA_ERR_TABLE_READONLY);
 
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-    table->timestamp_field->set_time();
   if (table->next_number_field && buf == table->record[0])
   {
     int error;
@@ -1093,8 +1091,6 @@ int ha_myisammrg::update_row(const uchar * old_data, uchar * new_data)
 {
   DBUG_ASSERT(this->file->children_attached);
   ha_statistic_increment(&SSV::ha_update_count);
-  if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
-    table->timestamp_field->set_time();
   return myrg_update(file,old_data,new_data);
 }
 
diff --git a/storage/xtradb/handler/ha_innodb.cc b/storage/xtradb/handler/ha_innodb.cc
index 97a30a81d12..004d57e6efd 100644
--- a/storage/xtradb/handler/ha_innodb.cc
+++ b/storage/xtradb/handler/ha_innodb.cc
@@ -5933,9 +5933,6 @@ ha_innobase::write_row(
 		DBUG_RETURN(HA_ERR_CRASHED);
 	}
 
-	if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_INSERT)
-		table->timestamp_field->set_time();
-
 	sql_command = thd_sql_command(user_thd);
 
 	if ((sql_command == SQLCOM_ALTER_TABLE
@@ -6359,9 +6356,6 @@ ha_innobase::update_row(
 		DBUG_RETURN(HA_ERR_CRASHED);
 	}
 
-	if (table->timestamp_field_type & TIMESTAMP_AUTO_SET_ON_UPDATE)
-		table->timestamp_field->set_time();
-
 	if (prebuilt->upd_node) {
 		uvect = prebuilt->upd_node->update;
 	} else {