MDEV-14605 Changes to "ON UPDATE CURRENT_TIMESTAMP" fields are not

           always logged properly with binlog_row_image=MINIMAL

There are two issues fixed in this commit.
The first is an observation of a multi-table UPDATE binlogged
in row-format in binlog_row_image=MINIMAL mode. While the UPDATE aims
at a table with an ON-UPDATE attribute its binlog after-image misses
to record also installed default value.
The reason for that turns out missed marking of default-capable fields
in TABLE::write_set.

This is fixed to mark such fields similarly to 10.2's MDEV-10134 patch (db7edfed17efe6)
that introduced it. The marking follows up 93d1e5ce0b841bed's idea
to exploit TABLE:rpl_write_set introduced there though,
and thus does not mess (in 10.1) with the actual MDEV-10134 agenda.
The patch makes formerly arg-less TABLE::mark_default_fields_for_write()
to accept an argument which would be TABLE:rpl_write_set.

The 2nd issue is extra columns in in binlog_row_image=MINIMAL before-image
while merely a packed primary key is enough. The test main.mysqlbinlog_row_minimal
always had a wrong result recorded.
This is fixed to invoke a function that intended for read_set
possible filtering and which is called (supposed to) in all type of MDL, UPDATE
including; the test results have gotten corrected.

At *merging* from 10.1->10.2 the 1st "main" part of the patch is unnecessary
since the bug is not observed in 10.2, so only hunks from

  sql/sql_class.cc

are required.

1 files changed, 21 insertions, 2 deletions

diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 8424b4477c3..0971d4fdaaa 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -6390,6 +6390,22 @@ int THD::binlog_update_row(TABLE* table, bool is_trans,
   DBUG_ASSERT(is_current_stmt_binlog_format_row() &&
             ((WSREP(this) && wsrep_emulate_bin_log) || mysql_bin_log.is_open()));
 
+  /**
+    Save a reference to the original read bitmaps
+    We will need this to restore the bitmaps at the end as
+    binlog_prepare_row_images() may change table->read_set.
+    table->read_set is used by pack_row and deep in
+    binlog_prepare_pending_events().
+  */
+  MY_BITMAP *old_read_set= table->read_set;
+
+  /**
+     This will remove spurious fields required during execution but
+     not needed for binlogging. This is done according to the:
+     binlog-row-image option.
+   */
+  binlog_prepare_row_images(table);
+
   size_t const before_maxlen = max_row_length(table, before_record);
   size_t const after_maxlen  = max_row_length(table, after_record);
 
@@ -6401,9 +6417,9 @@ int THD::binlog_update_row(TABLE* table, bool is_trans,
   uchar *after_row= row_data.slot(1);
 
   size_t const before_size= pack_row(table, table->read_set, before_row,
-                                        before_record);
+                                     before_record);
   size_t const after_size= pack_row(table, table->rpl_write_set, after_row,
-                                       after_record);
+                                    after_record);
 
   /* Ensure that all events in a GTID group are in the same cache */
   if (variables.option_bits & OPTION_GTID_BEGIN)
@@ -6431,6 +6447,9 @@ int THD::binlog_update_row(TABLE* table, bool is_trans,
   int error=  ev->add_row_data(before_row, before_size) ||
               ev->add_row_data(after_row, after_size);
 
+  /* restore read set for the rest of execution */
+  table->column_bitmaps_set_no_signal(old_read_set,
+                                      table->write_set);
   return error;
 
 }