Fix for BUG#51716 and BUG#51787.

In BUG#51787 we were using the wrong charset to print out the
data. We were using the field charset for the string that would
hold the information. This caused the assertion, because the
string length was not aligned with UTF32 bytes requirements for
storage.

We fix this by using &my_charset_latin1 in the string object
instead of the field->charset(). As a side-effect, we needed to
extend the show_sql_type interface so that it took the field
charset is now passed as a parameter, so that one is able to
calculate the correct field size.

In BUG#51716 we had issues with Field_string::pack and
Field_string::unpack. When packing, the length was incorrectly
calculated. When unpacking, the padding the string would be
padded with the wrong bytes (a few bytes less than it should).

We fix this by resorting to charset abstractions (functions) that
calculate the correct length when packing and pad correctly the
string when unpacking.

1 files changed, 8 insertions, 8 deletions

diff --git a/sql/rpl_utility.cc b/sql/rpl_utility.cc
index feb35527b62..8171d028326 100644
--- a/sql/rpl_utility.cc
+++ b/sql/rpl_utility.cc
@@ -340,7 +340,7 @@ uint32 table_def::calc_field_size(uint col, uchar *master_data) const
 
 /**
  */
-void show_sql_type(enum_field_types type, uint16 metadata, String *str)
+void show_sql_type(enum_field_types type, uint16 metadata, String *str, CHARSET_INFO *field_cs)
 {
   DBUG_ENTER("show_sql_type");
   DBUG_PRINT("enter", ("type: %d, metadata: 0x%x", type, metadata));
@@ -489,7 +489,7 @@ void show_sql_type(enum_field_types type, uint16 metadata, String *str)
       uint bytes= (((metadata >> 4) & 0x300) ^ 0x300) + (metadata & 0x00ff);
       uint32 length=
         cs->cset->snprintf(cs, (char*) str->ptr(), str->alloced_length(),
-                           "char(%d)", bytes / cs->mbmaxlen);
+                           "char(%d)", bytes / field_cs->mbmaxlen);
       str->length(length);
     }
     break;
@@ -579,7 +579,7 @@ can_convert_field_to(Field *field,
   DBUG_ENTER("can_convert_field_to");
 #ifndef DBUG_OFF
   char field_type_buf[MAX_FIELD_WIDTH];
-  String field_type(field_type_buf, sizeof(field_type_buf), field->charset());
+  String field_type(field_type_buf, sizeof(field_type_buf), &my_charset_latin1);
   field->sql_type(field_type);
   DBUG_PRINT("enter", ("field_type: %s, target_type: %d, source_type: %d, source_metadata: 0x%x",
                        field_type.c_ptr_safe(), field->real_type(), source_type, metadata));
@@ -822,9 +822,9 @@ table_def::compatible_with(THD *thd, Relay_log_info *rli,
       const char *tbl_name= table->s->table_name.str;
       char source_buf[MAX_FIELD_WIDTH];
       char target_buf[MAX_FIELD_WIDTH];
-      String source_type(source_buf, sizeof(source_buf), field->charset());
-      String target_type(target_buf, sizeof(target_buf), field->charset());
-      show_sql_type(type(col), field_metadata(col), &source_type);
+      String source_type(source_buf, sizeof(source_buf), &my_charset_latin1);
+      String target_type(target_buf, sizeof(target_buf), &my_charset_latin1);
+      show_sql_type(type(col), field_metadata(col), &source_type, field->charset());
       field->sql_type(target_type);
       rli->report(ERROR_LEVEL, ER_SLAVE_CONVERSION_FAILED,
                   ER(ER_SLAVE_CONVERSION_FAILED),
@@ -842,8 +842,8 @@ table_def::compatible_with(THD *thd, Relay_log_info *rli,
       {
         char source_buf[MAX_FIELD_WIDTH];
         char target_buf[MAX_FIELD_WIDTH];
-        String source_type(source_buf, sizeof(source_buf), table->field[col]->charset());
-        String target_type(target_buf, sizeof(target_buf), table->field[col]->charset());
+        String source_type(source_buf, sizeof(source_buf), &my_charset_latin1);
+        String target_type(target_buf, sizeof(target_buf), &my_charset_latin1);
         tmp_table->field[col]->sql_type(source_type);
         table->field[col]->sql_type(target_type);
         DBUG_PRINT("debug", ("Field %s - conversion required."