Bug#41465: confusing error message when comment is too long

The problem was that the server was trying to use the unknown
error format string (ER_UNKNOWN_ERROR) to print messages about
comments being too long, but the said format string does not
accept arguments and will always default to "Unknown error".

The solution is to introduce new error messages which are
specific to the error conditions so that server wants to
signal -- this also means that it's possible to translate
those messages.

mysql-test/r/strict.result:
  Update test case result.
mysql-test/t/strict.test:
  Update test case with new errors.
sql/share/errmsg.txt:
  Introduce new errors for long comments.
sql/unireg.cc:
  Use new errors.

1 files changed, 8 insertions, 9 deletions

diff --git a/sql/unireg.cc b/sql/unireg.cc
index da018ebec3d..51293184ad8 100644
--- a/sql/unireg.cc
+++ b/sql/unireg.cc
@@ -229,16 +229,16 @@ bool mysql_create_frm(THD *thd, const char *file_name,
                                               create_info->comment.length, 60);
   if (tmp_len < create_info->comment.length)
   {
-    (void) my_snprintf(buff, sizeof(buff), "Too long comment for table '%s'",
-                       table);
     if ((thd->variables.sql_mode &
          (MODE_STRICT_TRANS_TABLES | MODE_STRICT_ALL_TABLES)))
     {
-      my_message(ER_UNKNOWN_ERROR, buff, MYF(0));
+      my_error(ER_TOO_LONG_TABLE_COMMENT, MYF(0), table, tmp_len);
       goto err;
     }
     push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
-                        ER_UNKNOWN_ERROR, ER(ER_UNKNOWN_ERROR), buff);
+                        ER_TOO_LONG_TABLE_COMMENT,
+                        ER(ER_TOO_LONG_TABLE_COMMENT),
+                        table, tmp_len);
     create_info->comment.length= tmp_len;
   }
 
@@ -613,17 +613,16 @@ static bool pack_header(uchar *forminfo, enum legacy_db_type table_type,
                                                      255);
     if (tmp_len < field->comment.length)
     {
-      char buff[128];
-      (void) my_snprintf(buff,sizeof(buff), "Too long comment for field '%s'",
-                         field->field_name);
       if ((current_thd->variables.sql_mode &
 	   (MODE_STRICT_TRANS_TABLES | MODE_STRICT_ALL_TABLES)))
       {
-        my_message(ER_UNKNOWN_ERROR, buff, MYF(0));
+        my_error(ER_TOO_LONG_FIELD_COMMENT, MYF(0), field->field_name, tmp_len);
 	DBUG_RETURN(1);
       }
       push_warning_printf(current_thd, MYSQL_ERROR::WARN_LEVEL_WARN,
-                          ER_UNKNOWN_ERROR, ER(ER_UNKNOWN_ERROR), buff);
+                          ER_TOO_LONG_FIELD_COMMENT,
+                          ER(ER_TOO_LONG_FIELD_COMMENT),
+                          field->field_name, tmp_len);
       field->comment.length= tmp_len;
     }