Improved UTF-8 validation in JSON

diff --git a/ext/json/json_encoder.c b/ext/json/json_encoder.c
index c88d355fc00e790018b112025c64052fd2e85a3d..545d229f35f82ffc8f7fd94c43cdbac6dffec992 100644 (file)
--- a/ext/json/json_encoder.c
+++ b/ext/json/json_encoder.c
@@ -246,40 +246,23 @@ static int php_json_encode_array(smart_str *buf, zval *val, int options, php_jso
 }
 /* }}} */
 
-static int php_json_utf8_to_utf16(unsigned short *utf16, char utf8[], size_t len) /* {{{ */
+static int php_json_valid_utf8(char utf8[], size_t len) /* {{{ */
 {
        size_t pos = 0, us;
-       int j, status;
+       int status;
 
-       if (utf16) {
-               /* really convert the utf8 string */
-               for (j=0 ; pos < len ; j++) {
-                       us = php_next_utf8_char((const unsigned char *)utf8, len, &pos, &status);
-                       if (status != SUCCESS) {
-                               return -1;
-                       }
-                       /* From http://en.wikipedia.org/wiki/UTF16 */
-                       if (us >= 0x10000) {
-                               us -= 0x10000;
-                               utf16[j++] = (unsigned short)((us >> 10) | 0xd800);
-                               utf16[j] = (unsigned short)((us & 0x3ff) | 0xdc00);
-                       } else {
-                               utf16[j] = (unsigned short)us;
-                       }
-               }
-       } else {
-               /* Only check if utf8 string is valid, and compute utf16 length */
-               for (j=0 ; pos < len ; j++) {
+       while (pos < len) {
+               us = (unsigned char)utf8[pos];
+               if (us < 0x80) {
+                       pos++;
+               } else {
                        us = php_next_utf8_char((const unsigned char *)utf8, len, &pos, &status);
                        if (status != SUCCESS) {
-                               return -1;
-                       }
-                       if (us >= 0x10000) {
-                               j++;
+                               return 0;
                        }
                }
        }
-       return j;
+       return 1;
 }
 /* }}} */
 
@@ -315,7 +298,7 @@ static int php_json_escape_string(
 
        if (options & PHP_JSON_UNESCAPED_UNICODE) {
                /* validate UTF-8 string first */
-               if (php_json_utf8_to_utf16(NULL, s, len) < 0) {
+               if (!php_json_valid_utf8(s, len)) {
                        encoder->error_code = PHP_JSON_ERROR_UTF8;
                        if (options & PHP_JSON_PARTIAL_OUTPUT_ON_ERROR) {
                                smart_str_appendl(buf, "null", 4);