[MDEV-6877] Change replication event loop to account for empty events10.1-MDEV-6877-binlog_row_image

When writing rows with a minimal row image, it is possible to receive
empty events. In that case m_curr_row and m_rows_end are the same,
however the event implies an insert into the table with the default
values associated for that table.

1 files changed, 10 insertions, 0 deletions

diff --git a/sql/rpl_record.cc b/sql/rpl_record.cc
index 8c694602c74..feab97fd589 100644
--- a/sql/rpl_record.cc
+++ b/sql/rpl_record.cc
@@ -209,6 +209,16 @@ unpack_row(rpl_group_info *rgi,
   Field **field_ptr;
   Field **const end_ptr= begin_ptr + colcnt;
 
+  if (bitmap_is_clear_all(cols))
+  {
+    /**
+       There was no data sent from the master, so there is
+       nothing to unpack.
+     */
+    *current_row_end= pack_ptr;
+    *master_reclength= 0;
+    DBUG_RETURN(error);
+  }
   DBUG_ASSERT(null_ptr < row_data + master_null_byte_count);
 
   // Mask to mask out the correct bit among the null bits