BUG#12558519: RPL_TYPECONV PRODUCES VALGRIND STACK

In RBR and in case of converting blob fields, the space allocated
while unpacking into the conversion field was not freed after
copying from it into the real field.

We fix this by freeing the conversion field when the conversion
table is not needed anymore (on close_tables_to_lock).

1 files changed, 9 insertions, 1 deletions

diff --git a/sql/table.cc b/sql/table.cc
index 68e2566ffc1..8073120e530 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -2188,7 +2188,15 @@ void free_blobs(register TABLE *table)
   for (ptr= table->s->blob_field, end=ptr + table->s->blob_fields ;
        ptr != end ;
        ptr++)
-    ((Field_blob*) table->field[*ptr])->free();
+  {
+    /*
+      Reduced TABLE objects which are used by row-based replication for
+      type conversion might have some fields missing. Skip freeing BLOB
+      buffers for such missing fields.
+    */
+    if (table->field[*ptr])
+      ((Field_blob*) table->field[*ptr])->free();
+  }
 }