BUG#17066269: AUTO_INC VALUE NOT PROPERLY GENERATED WITH RBR AND

AUTO_INC COLUMN ONLY ON SLAVE

In RBR, if the slave's table as one additional auto_inc column,
then, it will insert the value 0 instead of generating the next
auto_inc number.

We fix this by checking that if an auto_inc extra column exists,
when compared to column data of the row event, we explicitly set
it to NULL and flag the engine that a nulled auto_inc column will
be inserted.

sql/log_event.cc

@@ -8030,10 +8030,14 @@ int Rows_log_event::do_apply_event(Relay_log_info const *rli)
     /*
       Bug#56662 Assertion failed: next_insert_id == 0, file handler.cc
       Don't allow generation of auto_increment value when processing
-      rows event by setting 'MODE_NO_AUTO_VALUE_ON_ZERO'.
+      rows event by setting 'MODE_NO_AUTO_VALUE_ON_ZERO'. The exception
+      to this rule happens when the auto_inc column exists on some 
+      extra columns on the slave. In that case, do not force 
+      MODE_NO_AUTO_VALUE_ON_ZERO.
     */
     ulong saved_sql_mode= thd->variables.sql_mode;
-    thd->variables.sql_mode= MODE_NO_AUTO_VALUE_ON_ZERO;
+    if (!is_auto_inc_in_extra_columns())
+      thd->variables.sql_mode= MODE_NO_AUTO_VALUE_ON_ZERO;
 
     // row processing loop
 
@@ -9088,9 +9092,28 @@ Write_rows_log_event::do_before_row_operations(const Slave_reporting_capability
    * table->auto_increment_field_not_null and SQL_MODE(if includes
    * MODE_NO_AUTO_VALUE_ON_ZERO) in update_auto_increment function.
    * SQL_MODE of slave sql thread is always consistency with master's.
-   * In RBR, auto_increment fields never are NULL.
+   * In RBR, auto_increment fields never are NULL, except if the auto_inc
+   * column exists only on the slave side (i.e., in an extra column
+   * on the slave's table).
    */
-  m_table->auto_increment_field_not_null= TRUE;
+  if (!is_auto_inc_in_extra_columns())
+    m_table->auto_increment_field_not_null= TRUE;
+  else
+  {
+    /*
+      Here we have checked that there is an extra field
+      on this server's table that has an auto_inc column.
+
+      Mark that the auto_increment field is null and mark
+      the read and write set bits.
+
+      (There can only be one AUTO_INC column, it is always
+       indexed and it cannot have a DEFAULT value).
+    */
+    m_table->auto_increment_field_not_null= FALSE;
+    m_table->mark_auto_increment_column();
+  }
+
   return error;
 }
 
@@ -9099,6 +9122,19 @@ Write_rows_log_event::do_after_row_operations(const Slave_reporting_capability *
                                               int error)
 {
   int local_error= 0;
+
+  /**
+    Clear the write_set bit for auto_inc field that only
+    existed on the destination table as an extra column.
+   */
+  if (is_auto_inc_in_extra_columns())
+  {
+    bitmap_clear_bit(m_table->write_set, m_table->next_number_field->field_index);
+    bitmap_clear_bit( m_table->read_set, m_table->next_number_field->field_index);
+
+    if (get_flags(STMT_END_F))
+      m_table->file->ha_release_auto_increment();
+  }
   m_table->next_number_field=0;
   m_table->auto_increment_field_not_null= FALSE;
   if ((slave_exec_mode == SLAVE_EXEC_MODE_IDEMPOTENT) ||
@@ -9222,7 +9258,13 @@ Rows_log_event::write_row(const Relay_log_info *const rli,
     ulong estimated_rows= (m_rows_end - m_curr_row) / (m_curr_row_end - m_curr_row);
     m_table->file->ha_start_bulk_insert(estimated_rows);
   }
-  
+
+  /*
+    Explicitly set the auto_inc to null to make sure that
+    it gets an auto_generated value.
+  */
+  if (is_auto_inc_in_extra_columns())
+    m_table->next_number_field->set_null();
   
 #ifndef DBUG_OFF
   DBUG_DUMP("record[0]", table->record[0], table->s->reclength);

sql/log_event.h

@@ -3739,6 +3739,20 @@ protected:
     ASSERT_OR_RETURN_ERROR(m_curr_row_end <= m_rows_end, HA_ERR_CORRUPT_EVENT);
     return result;
   }
+
+  /**
+    Helper function to check whether there is an auto increment
+    column on the table where the event is to be applied.
+
+    @return true if there is an autoincrement field on the extra
+            columns, false otherwise.
+   */
+  inline bool is_auto_inc_in_extra_columns()
+  {
+    DBUG_ASSERT(m_table);
+    return (m_table->next_number_field &&
+            m_table->next_number_field->field_index >= m_width);
+  }
 #endif
 
 private: