Merge 10.3.7 into 10.4shagalla-10.4

1 files changed, 16 insertions, 0 deletions

diff --git a/sql/rpl_utility.cc b/sql/rpl_utility.cc
index 58711078db6..31035fb5dcc 100644
--- a/sql/rpl_utility.cc
+++ b/sql/rpl_utility.cc
@@ -42,6 +42,12 @@ max_display_length_for_temporal2_field(uint32 int_display_length,
    @param sql_type Type of the field
    @param metadata The metadata from the master for the field.
    @return Maximum length of the field in bytes.
+
+   The precise values calculated by field->max_display_length() and
+   calculated by max_display_length_for_field() can differ (by +1 or -1)
+   for integer data types (TINYINT, SMALLINT, MEDIUMINT, INT, BIGINT).
+   This slight difference is not important here, because we call
+   this function only for two *different* integer data types.
  */
 static uint32
 max_display_length_for_field(enum_field_types sql_type, unsigned int metadata)
@@ -737,6 +743,16 @@ can_convert_field_to(Field *field,
     case MYSQL_TYPE_INT24:
     case MYSQL_TYPE_LONG:
     case MYSQL_TYPE_LONGLONG:
+      /*
+        max_display_length_for_field() is not fully precise for the integer
+        data types. So its result cannot be compared to the result of
+        field->max_dispay_length() when the table field and the binlog field
+        are of the same type.
+        This code should eventually be rewritten not to use
+        compare_lengths(), to detect subtype/supetype relations
+        just using the type codes.
+      */
+      DBUG_ASSERT(source_type != field->real_type());
       *order_var= compare_lengths(field, source_type, metadata);
       DBUG_ASSERT(*order_var != 0);
       DBUG_RETURN(is_conversion_ok(*order_var, rli));