branches/zip: Add the function dtype_is_utf8().

include/data0type.h

@@ -275,6 +275,16 @@ dtype_form_prtype(
 				DATA_BINARY_TYPE etc. */
 	ulint	charset_coll);	/* in: MySQL charset-collation code */
 /*************************************************************************
+Determines if a MySQL string type is a subset of UTF-8.  This function
+may return false negatives, in case further character-set collation
+codes are introduced in MySQL later. */
+UNIV_INLINE
+ibool
+dtype_is_utf8(
+/*==========*/
+			/* out: TRUE if a subset of UTF-8 */
+	ulint	prtype);/* in: precise data type */
+/*************************************************************************
 Gets the type length. */
 UNIV_INLINE
 ulint

include/data0type.ic

@@ -34,6 +34,31 @@ dtype_get_charset_coll(
 	return((prtype >> 16) & 0xFFUL);
 }
 
+/*************************************************************************
+Determines if a MySQL string type is a subset of UTF-8.  This function
+may return false negatives, in case further character-set collation
+codes are introduced in MySQL later. */
+UNIV_INLINE
+ibool
+dtype_is_utf8(
+/*==========*/
+			/* out: TRUE if a subset of UTF-8 */
+	ulint	prtype)	/* in: precise data type */
+{
+	/* These codes have been copied from strings/ctype-extra.c
+	and strings/ctype-utf8.c. */
+	switch (dtype_get_charset_coll(prtype)) {
+	case 11: /* ascii_general_ci */
+	case 65: /* ascii_bin */
+	case 33: /* utf8_general_ci */
+	case 83: /* utf8_bin */
+	case 254: /* utf8_general_cs */
+			return(TRUE);
+	}
+
+	return(FALSE);
+}
+
 /*************************************************************************
 Gets the MySQL type code from a dtype. */
 UNIV_INLINE