change to separate by 256 bytes, when C->fetched_len == SQL_NO_TOTAL

Author: SakiTakamachi

ext/pdo_odbc/odbc_stmt.c

@@ -684,11 +684,24 @@ static int odbc_stmt_get_col(pdo_stmt_t *stmt, int colno, zval *result, enum pdo
 			 * The extension previously tried getting it in 256
 			 * byte blocks, but this could have created trouble
 			 * with some drivers.
+			 *
+			 * However, depending on the driver, fetched_len may
+			 * not contain the number of bytes and SQL_NO_TOTAL
+			 * may be passed.
+			 * In that case, the operation will be the same as
+			 * before, dividing the data into 256-byte blocks.
 			 */
-			SQLLEN to_fetch_len = orig_fetched_len + 1; /* for 0 at end */
+			SQLLEN to_fetch_len;
+			size_t used;
+			if (C->fetched_len == SQL_NO_TOTAL) {
+				to_fetch_len = 256;
+				used = 255; /* not 256; the driver NUL terminated the buffer */
+			} else {
+				to_fetch_len = orig_fetched_len + 1; /* for 0 at end */
+				used = orig_fetched_len; /* not n + 1; the driver NUL terminated the buffer */
+			}
 			char *buf2 = emalloc(to_fetch_len);
 			zend_string *str = zend_string_init(C->data, to_fetch_len, 0);
-			size_t used = orig_fetched_len; /* not n + 1; the driver NUL terminated the buffer */
 
 			do {
 				C->fetched_len = 0;