Commit 3fd4bb02 authored by unknown's avatar unknown
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ha_innodb.cc: 

  A partial bugfix to a multibyte charset / column prefix index bug: my_charpos() does not handle right some cases, we try to mask the bug for ASCII chars < 128 in the UTF-8 charset


sql/ha_innodb.cc:
  A partial bugfix to a multibyte charset / column prefix index bug: my_charpos() does not handle right some cases, we try to mask the bug for ASCII chars < 128 in the UTF-8 charset
parent 32c36a20

sql/ha_innodb.cc

+32 −6
Original line number Diff line number Diff line
@@ -5317,13 +5317,10 @@ innobase_get_at_most_n_mbchars( 
	ulint data_len,         /* in: length of the string in bytes */

	const char* str)	/* in: character string */

{

	ulint byte_length;	/* string length in bytes. */

	ulint char_length;	/* character length in bytes */

	ulint n_chars;		/* number of characters in prefix */

	CHARSET_INFO* charset;	/* charset used in the field */



	byte_length = data_len;



	charset = get_charset(charset_id, MYF(MY_WME));



	ut_ad(charset);
@@ -5339,14 +5336,43 @@ innobase_get_at_most_n_mbchars( 
	full character. */



	if (charset->mbmaxlen > 1) {

/*		ulint	right_value; */



		/* my_charpos() returns the byte length of the first n_chars

		characters, or the end of the last full character */



		char_length = my_charpos(charset, str,

					 str + byte_length, n_chars);

						str + data_len, n_chars);

	

		/*################################################*/

		/* TODO: my_charpos sometimes returns a non-sensical value

		that is BIGGER than data_len: try to fix this bug partly with

		these heuristics. This is NOT a complete bug fix! */



		if (char_length > data_len) {

			char_length = data_len;

		}		

		/*################################################*/



/*		printf("data_len %lu, n_chars %lu, char_len %lu\n",

				data_len, n_chars, char_length);

		if (data_len < n_chars) {

			right_value = data_len;

		} else {

			right_value = n_chars;

		}



		if (right_value != char_length) {

			printf("ERRRRRROOORRRRRRRRRRRR!!!!!!!!!\n");

		}

*/

	} else {

		if (data_len < prefix_len) {

			char_length = data_len;

		} else {

			char_length = prefix_len;

		}

	}



	return(char_length);

}