MDEV-22558 wrong error for invalid utf8 table comment

mysql-test/r/comment_table.result

-DROP TABLE IF EXISTS t1;
 create table t1 (c1 VARCHAR(10) NOT NULL COMMENT 'c1 comment', c2 INTEGER,c3 INTEGER COMMENT '012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789', c4 INTEGER, c5 INTEGER, c6 INTEGER, c7 INTEGER, INDEX i1 (c1) COMMENT 'i1 comment',INDEX i2(c2) 
 ) COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcd';
 SELECT table_comment,char_length(table_comment) FROM information_schema.tables WHERE table_name='t1';
@@ -125,3 +124,7 @@ SELECT table_comment,char_length(table_comment) FROM information_schema.tables W
 table_comment	char_length(table_comment)
 SELECT column_comment,char_length(column_comment) FROM information_schema.columns WHERE table_name='t1';
 column_comment	char_length(column_comment)
+set names utf8;
+create table t1 (x int comment 'a');
+ERROR HY000: Invalid utf8 character string: 'a'
+set names latin1;

mysql-test/t/comment_table.test

---disable_warnings
-DROP TABLE IF EXISTS t1;
---enable_warnings
 #1024 bytes
 create table t1 (c1 VARCHAR(10) NOT NULL COMMENT 'c1 comment', c2 INTEGER,c3 INTEGER COMMENT '012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789', c4 INTEGER, c5 INTEGER, c6 INTEGER, c7 INTEGER, INDEX i1 (c1) COMMENT 'i1 comment',INDEX i2(c2) 
 ) COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcd';
@@ -53,3 +50,11 @@ create table t1 (c1 VARCHAR(10) NOT NULL COMMENT 'c1 comment', c2 INTEGER,c3 INT
 ) COMMENT='abcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcdefghijabcde';
 SELECT table_comment,char_length(table_comment) FROM information_schema.tables WHERE table_name='t1';
 SELECT column_comment,char_length(column_comment) FROM information_schema.columns WHERE table_name='t1';
+
+#
+# MDEV-22558 wrong error for invalid utf8 table comment
+#
+set names utf8;
+--error ER_INVALID_CHARACTER_STRING
+create table t1 (x int comment 'a');
+set names latin1;

sql/sql_table.cc

@@ -4294,6 +4294,25 @@ bool validate_comment_length(THD *thd, LEX_STRING *comment, size_t max_len,
       Well_formed_prefix(system_charset_info, *comment, max_len).length();
   if (tmp_len < comment->length)
   {
+#if MARIADB_VERSION_ID < 100500
+    if (comment->length <= max_len)
+    {
+      if (thd->is_strict_mode())
+      {
+         my_error(ER_INVALID_CHARACTER_STRING, MYF(0),
+                  system_charset_info->csname, comment->str);
+         DBUG_RETURN(true);
+      }
+      push_warning_printf(thd, Sql_condition::WARN_LEVEL_WARN,
+                          ER_INVALID_CHARACTER_STRING,
+                          ER_THD(thd, ER_INVALID_CHARACTER_STRING),
+                          system_charset_info->csname, comment->str);
+      comment->length= tmp_len;
+      DBUG_RETURN(false);
+    }
+#else
+#error do it in TEXT_STRING_sys
+#endif
     if (thd->is_strict_mode())
     {
        my_error(err_code, MYF(0), name, static_cast<ulong>(max_len));