BUG#49618: Field length stored incorrectly in binary log

           for InnoDB

The class Field_bit_as_char stores the metadata for the
field incorrecly because bytes_in_rec and bit_len are set
to (field_length + 7 ) / 8 and 0 respectively, while
Field_bit has the correct values field_length / 8 and
field_length % 8.

Solved the problem by re-computing the values for the
metadata based on the field_length instead of using the
bytes_in_rec and bit_len variables.

To handle compatibility with old server, a table map
flag was added to indicate that the bit computation is
exact. If the flag is clear, the slave computes the
number of bytes required to store the bit field and
compares that instead, effectively allowing replication
*without conversion* from any field length that require
the same number of bytes to store.

mysql-test/suite/rpl/r/rpl_typeconv_innodb.result

+stop slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+reset master;
+reset slave;
+drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
+start slave;
+**** Resetting master and slave ****
+include/stop_slave.inc
+RESET SLAVE;
+RESET MASTER;
+include/start_slave.inc
+SET @saved_slave_type_conversions = @@GLOBAL.SLAVE_TYPE_CONVERSIONS;
+SET GLOBAL SLAVE_TYPE_CONVERSIONS = '';
+CREATE TABLE t1(b1 BIT(1), b2 BIT(2), b3 BIT(3)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (b'0', b'01', b'101');
+Comparing tables master:test.t1 and slave:test.t1
+DROP TABLE t1;
+SET GLOBAL SLAVE_TYPE_CONVERSIONS = @saved_slave_type_conversions;

mysql-test/suite/rpl/t/rpl_typeconv-slave.opt

+--innodb
\ No newline at end of file

mysql-test/suite/rpl/t/rpl_typeconv_innodb.test

+--source include/have_binlog_format_row.inc
+--source include/have_innodb.inc
+--source include/master-slave.inc
+
+#
+# BUG#49618: Field length stored incorrectly in binary log for InnoDB
+#
+
+source include/reset_master_and_slave.inc;
+
+connection slave;
+SET @saved_slave_type_conversions = @@GLOBAL.SLAVE_TYPE_CONVERSIONS;
+SET GLOBAL SLAVE_TYPE_CONVERSIONS = '';
+
+connection master;
+CREATE TABLE t1(b1 BIT(1), b2 BIT(2), b3 BIT(3)) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (b'0', b'01', b'101');
+sync_slave_with_master;
+
+let $diff_table_1=master:test.t1;
+let $diff_table_2=slave:test.t1;
+source include/diff_tables.inc;
+
+connection master;
+DROP TABLE t1;
+sync_slave_with_master;
+
+connection slave;
+SET GLOBAL SLAVE_TYPE_CONVERSIONS = @saved_slave_type_conversions;

sql/field.cc

@@ -1407,6 +1407,7 @@ bool Field::send_binary(Protocol *protocol)
    type, 0 is returned in <code>*order_var</code>.
 
    @param   field_metadata   Encoded size in field metadata
+   @param   mflags           Flags from the table map event for the table.
    @param   order_var        Pointer to variable where the order
                              between the source field and this field
                              will be returned.
@@ -1416,6 +1417,7 @@ bool Field::send_binary(Protocol *protocol)
 */
 bool Field::compatible_field_size(uint field_metadata,
                                   Relay_log_info *rli_arg __attribute__((unused)),
+                                  uint16 mflags __attribute__((unused)),
                                   int *order_var)
 {
   uint const source_size= pack_length_from_metadata(field_metadata);
@@ -2950,6 +2952,7 @@ uint Field_new_decimal::pack_length_from_metadata(uint field_metadata)
 
 bool Field_new_decimal::compatible_field_size(uint field_metadata,
                                               Relay_log_info * __attribute__((unused)),
+                                              uint16 mflags __attribute__((unused)),
                                               int *order_var)
 {
   uint const source_precision= (field_metadata >> 8U) & 0x00ff;
@@ -6733,6 +6736,7 @@ check_field_for_37426(const void *param_arg)
 bool
 Field_string::compatible_field_size(uint field_metadata,
                                     Relay_log_info *rli_arg,
+                                    uint16 mflags __attribute__((unused)),
                                     int *order_var)
 {
 #ifdef HAVE_REPLICATION
@@ -6741,7 +6745,7 @@ Field_string::compatible_field_size(uint field_metadata,
                          check_field_for_37426, &check_param))
     return FALSE;                        // Not compatible field sizes
 #endif
-  return Field::compatible_field_size(field_metadata, rli_arg, order_var);
+  return Field::compatible_field_size(field_metadata, rli_arg, mflags, order_var);
 }
 
 
@@ -9305,8 +9309,13 @@ int Field_bit::do_save_field_metadata(uchar *metadata_ptr)
   DBUG_ENTER("Field_bit::do_save_field_metadata");
   DBUG_PRINT("debug", ("bit_len: %d, bytes_in_rec: %d",
                        bit_len, bytes_in_rec));
-  *metadata_ptr= bit_len;
-  *(metadata_ptr + 1)= bytes_in_rec;
+  /*
+    Since this class and Field_bit_as_char have different ideas of
+    what should be stored here, we compute the values of the metadata
+    explicitly using the field_length.
+   */
+  metadata_ptr[0]= field_length % 8;
+  metadata_ptr[1]= field_length / 8;
   DBUG_RETURN(2);
 }
 
@@ -9335,15 +9344,29 @@ uint Field_bit::pack_length_from_metadata(uint field_metadata)
 bool
 Field_bit::compatible_field_size(uint field_metadata,
                                  Relay_log_info * __attribute__((unused)),
+                                 uint16 mflags,
                                  int *order_var)
 {
   DBUG_ENTER("Field_bit::compatible_field_size");
   DBUG_ASSERT((field_metadata >> 16) == 0);
-  uint const from_bit_len=
+  uint from_bit_len=
     8 * (field_metadata >> 8) + (field_metadata & 0xff);
-  uint const to_bit_len= max_display_length();
+  uint to_bit_len= max_display_length();
   DBUG_PRINT("debug", ("from_bit_len: %u, to_bit_len: %u",
                        from_bit_len, to_bit_len));
+  /*
+    If the bit length exact flag is clear, we are dealing with an old
+    master, so we allow some less strict behaviour if replicating by
+    moving both bit lengths to an even multiple of 8.
+
+    We do this by computing the number of bytes to store the field
+    instead, and then compare the result.
+   */
+  if (!(mflags & Table_map_log_event::TM_BIT_LEN_EXACT_F)) {
+    from_bit_len= (from_bit_len + 7) / 8;
+    to_bit_len= (to_bit_len + 7) / 8;
+  }
+
   *order_var= compare(from_bit_len, to_bit_len);
   DBUG_RETURN(TRUE);
 }

sql/field.h

@@ -165,7 +165,7 @@ public:
   */
   virtual uint32 pack_length_in_rec() const { return pack_length(); }
   virtual bool compatible_field_size(uint metadata, Relay_log_info *rli,
-                                     int *order);
+                                     uint16 mflags, int *order);
   virtual uint pack_length_from_metadata(uint field_metadata)
   {
     DBUG_ENTER("Field::pack_length_from_metadata");
@@ -805,7 +805,7 @@ public:
   uint pack_length_from_metadata(uint field_metadata);
   uint row_pack_length() { return pack_length(); }
   bool compatible_field_size(uint field_metadata, Relay_log_info *rli,
-                             int *order_var);
+                             uint16 mflags, int *order_var);
   uint is_equal(Create_field *new_field);
   virtual const uchar *unpack(uchar* to, const uchar *from,
                               uint param_data, bool low_byte_first);
@@ -1500,7 +1500,7 @@ public:
     return (((field_metadata >> 4) & 0x300) ^ 0x300) + (field_metadata & 0x00ff);
   }
   bool compatible_field_size(uint field_metadata, Relay_log_info *rli,
-                             int *order_var);
+                             uint16 mflags, int *order_var);
   uint row_pack_length() { return field_length; }
   int pack_cmp(const uchar *a,const uchar *b,uint key_length,
                my_bool insert_or_update);
@@ -1964,7 +1964,7 @@ public:
   uint row_pack_length()
   { return (bytes_in_rec + ((bit_len > 0) ? 1 : 0)); }
   bool compatible_field_size(uint metadata, Relay_log_info *rli,
-                             int *order_var);
+                             uint16 mflags, int *order_var);
   void sql_type(String &str) const;
   virtual uchar *pack(uchar *to, const uchar *from,
                       uint max_length, bool low_byte_first);

sql/log.cc

@@ -3846,11 +3846,8 @@ int THD::binlog_write_table_map(TABLE *table, bool is_trans)
   DBUG_ASSERT(current_stmt_binlog_row_based && mysql_bin_log.is_open());
   DBUG_ASSERT(table->s->table_map_id != ULONG_MAX);
 
-  Table_map_log_event::flag_set const
-    flags= Table_map_log_event::TM_NO_FLAGS;
-
   Table_map_log_event
-    the_event(this, table, table->s->table_map_id, is_trans, flags);
+    the_event(this, table, table->s->table_map_id, is_trans);
 
   if (is_trans && binlog_table_maps == 0)
     binlog_start_trans_and_stmt();

sql/log_event.cc

@@ -7852,7 +7852,7 @@ int Table_map_log_event::save_field_metadata()
  */
 #if !defined(MYSQL_CLIENT)
 Table_map_log_event::Table_map_log_event(THD *thd, TABLE *tbl, ulong tid,
-                                         bool is_transactional, uint16 flags)
+                                         bool is_transactional)
   : Log_event(thd, 0, true),
     m_table(tbl),
     m_dbnam(tbl->s->db.str),
@@ -7862,7 +7862,7 @@ Table_map_log_event::Table_map_log_event(THD *thd, TABLE *tbl, ulong tid,
     m_colcnt(tbl->s->fields),
     m_memory(NULL),
     m_table_id(tid),
-    m_flags(flags),
+    m_flags(TM_BIT_LEN_EXACT_F),
     m_data_size(0),
     m_field_metadata(0),
     m_field_metadata_size(0),
@@ -8120,8 +8120,10 @@ int Table_map_log_event::do_apply_event(Relay_log_info const *rli)
       inside Relay_log_info::clear_tables_to_lock() by calling the
       table_def destructor explicitly.
     */
-    new (&table_list->m_tabledef) table_def(m_coltype, m_colcnt, 
-         m_field_metadata, m_field_metadata_size, m_null_bits);
+    new (&table_list->m_tabledef)
+      table_def(m_coltype, m_colcnt,
+                m_field_metadata, m_field_metadata_size,
+                m_null_bits, m_flags);
     table_list->m_tabledef_valid= TRUE;
 
     /*

sql/log_event.h

@@ -3283,16 +3283,14 @@ public:
   /* Special constants representing sets of flags */
   enum 
   {
-    TM_NO_FLAGS = 0U
+    TM_NO_FLAGS = 0U,
+    TM_BIT_LEN_EXACT_F = (1U << 0)
   };
 
-  void set_flags(flag_set flag) { m_flags |= flag; }
-  void clear_flags(flag_set flag) { m_flags &= ~flag; }
   flag_set get_flags(flag_set flag) const { return m_flags & flag; }
 
 #ifndef MYSQL_CLIENT
-  Table_map_log_event(THD *thd, TABLE *tbl, ulong tid, 
-		      bool is_transactional, uint16 flags);
+  Table_map_log_event(THD *thd, TABLE *tbl, ulong tid, bool is_transactional);
 #endif
 #ifdef HAVE_REPLICATION
   Table_map_log_event(const char *buf, uint event_len, 
@@ -3305,7 +3303,7 @@ public:
   table_def *create_table_def()
   {
     return new table_def(m_coltype, m_colcnt, m_field_metadata,
-                         m_field_metadata_size, m_null_bits);
+                         m_field_metadata_size, m_null_bits, m_flags);
   }
   ulong get_table_id() const        { return m_table_id; }
   const char *get_table_name() const { return m_tblnam; }

sql/rpl_utility.cc

@@ -510,6 +510,9 @@ void show_sql_type(enum_field_types type, uint16 metadata, String *str)
 /**
    Check the order variable and print errors if the order is not
    acceptable according to the current settings.
+
+   @param order  The computed order of the conversion needed.
+   @param rli    The relay log info data structure: for error reporting.
  */
 bool is_conversion_ok(int order, Relay_log_info *rli)
 {
@@ -562,6 +565,7 @@ bool is_conversion_ok(int order, Relay_log_info *rli)
    @param[in] type     Source field type
    @param[in] metadata Source field metadata
    @param[in] rli      Relay log info (for error reporting)
+   @param[in] mflags   Flags from the table map event
    @param[out] order   Order between source field and target field
 
    @return @c true if conversion is possible according to the current
@@ -571,7 +575,8 @@ bool is_conversion_ok(int order, Relay_log_info *rli)
 static bool
 can_convert_field_to(Field *field,
                      enum_field_types source_type, uint16 metadata,
-                     Relay_log_info *rli, int *order_var)
+                     Relay_log_info *rli, uint16 mflags,
+                     int *order_var)
 {
   DBUG_ENTER("can_convert_field_to");
 #ifndef DBUG_OFF
@@ -588,7 +593,7 @@ can_convert_field_to(Field *field,
   if (field->real_type() == source_type)
   {
     DBUG_PRINT("debug", ("Base types are identical, doing field size comparison"));
-    if (field->compatible_field_size(metadata, rli, order_var))
+    if (field->compatible_field_size(metadata, rli, mflags, order_var))
       DBUG_RETURN(is_conversion_ok(*order_var, rli));
     else
       DBUG_RETURN(false);
@@ -765,7 +770,7 @@ table_def::compatible_with(THD *thd, Relay_log_info *rli,
   {
     Field *const field= table->field[col];
     int order;
-    if (can_convert_field_to(field, type(col), field_metadata(col), rli, &order))
+    if (can_convert_field_to(field, type(col), field_metadata(col), rli, m_flags, &order))
     {
       DBUG_PRINT("debug", ("Checking column %d -"
                            " field '%s' can be converted - order: %d",
@@ -937,9 +942,10 @@ TABLE *table_def::create_conversion_table(THD *thd, Relay_log_info *rli, TABLE *
 
 table_def::table_def(unsigned char *types, ulong size,
                      uchar *field_metadata, int metadata_size,
-                     uchar *null_bitmap)
+                     uchar *null_bitmap, uint16 flags)
   : m_size(size), m_type(0), m_field_metadata_size(metadata_size),
-    m_field_metadata(0), m_null_bits(0), m_memory(NULL)
+    m_field_metadata(0), m_null_bits(0), m_flags(flags),
+    m_memory(NULL)
 {
   m_memory= (uchar *)my_multi_malloc(MYF(MY_WME),
                                      &m_type, size,

sql/rpl_utility.h

@@ -33,12 +33,6 @@ class Relay_log_info;
   - Extract and decode table definition data from the table map event
   - Check if table definition in table map is compatible with table
     definition on slave
-
-  Currently, the only field type data available is an array of the
-  type operators that are present in the table map event.
-
-  @todo Add type operands to this structure to allow detection of
-     difference between, e.g., BIT(5) and BIT(10).
  */
 
 class table_def
@@ -54,7 +48,7 @@ public:
     @param null_bitmap The bitmap of fields that can be null
    */
   table_def(unsigned char *types, ulong size, uchar *field_metadata,
-            int metadata_size, uchar *null_bitmap);
+            int metadata_size, uchar *null_bitmap, uint16 flags);
 
   ~table_def();
 
@@ -215,6 +209,7 @@ private:
   uint m_field_metadata_size;
   uint16 *m_field_metadata;
   uchar *m_null_bits;
+  uint16 m_flags;         // Table flags
   uchar *m_memory;
 };