Merge remote-tracking branch 'bd808/feature/clean-json'

src/Monolog/Formatter/NormalizerFormatter.php

@@ -138,25 +138,76 @@ class NormalizerFormatter implements FormatterInterface
         return $data;
     }
 
+    /**
+     * Return the JSON representation of a value
+     *
+     * @param mixed $data
+     * @param bool  $ignoreErrors
+     * @return string
+     * @throws \RuntimeException if encoding fails and errors are not ignored
+     */
     protected function toJson($data, $ignoreErrors = false)
     {
         // suppress json_encode errors since it's twitchy with some inputs
         if ($ignoreErrors) {
-            if (version_compare(PHP_VERSION, '5.4.0', '>=')) {
-                return @json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
-            }
-
-            return @json_encode($data);
+            return @$this->jsonEncode($data);
         }
 
-        if (version_compare(PHP_VERSION, '5.4.0', '>=')) {
-            $json = json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
-        } else {
-            $json = json_encode($data);
-        }
+        $json = $this->jsonEncode($data);
 
         if ($json === false) {
-            $this->throwEncodeError(json_last_error(), $data);
+            $json = $this->handleJsonError(json_last_error(), $data);
+        }
+
+        return $json;
+    }
+
+    /**
+     * @param mixed $data
+     * @return string JSON encoded data or null on failure
+     */
+    private function jsonEncode($data)
+    {
+        if (version_compare(PHP_VERSION, '5.4.0', '>=')) {
+            return json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
+        }
+
+        return json_encode($data);
+    }
+
+    /**
+     * Handle a json_encode failure.
+     *
+     * If the failure is due to invalid string encoding, try to clean the
+     * input and encode again. If the second encoding iattempt fails, the
+     * inital error is not encoding related or the input can't be cleaned then
+     * raise a descriptive exception.
+     *
+     * @param int   $code return code of json_last_error function
+     * @param mixed $data data that was meant to be encoded
+     * @return string JSON encoded data after error correction
+     * @throws \RuntimeException if failure can't be corrected
+     */
+    private function handleJsonError($code, $data)
+    {
+        if ($code !== JSON_ERROR_UTF8) {
+            $this->throwEncodeError($code, $data);
+        }
+
+        if (is_string($data)) {
+            $this->detectAndCleanUtf8($data);
+
+        } elseif (is_array($data)) {
+            array_walk_recursive($data, array($this, 'detectAndCleanUtf8'));
+
+        } else {
+            $this->throwEncodeError($code, $data);
+        }
+
+        $json = $this->jsonEncode($data);
+
+        if ($json === false) {
+            $json = $this->throwEncodeError(json_last_error(), $data);
         }
 
         return $json;
@@ -190,4 +241,36 @@ class NormalizerFormatter implements FormatterInterface
 
         throw new \RuntimeException('JSON encoding failed: '.$msg.'. Encoding: '.var_export($data, true));
     }
+
+    /**
+     * Detect invalid UTF-8 string characters and convert to valid UTF-8.
+     *
+     * Valid UTF-8 input will be left unmodified, but strings containing
+     * invalid UTF-8 codepoints will be reencoded as UTF-8 with an assumed
+     * original encoding of ISO-8859-15. This conversion may result in
+     * incorrect output if the actual encoding was not ISO-8859-15, but it
+     * will be clean UTF-8 output and will not rely on expensive and fragile
+     * detection algorithms.
+     *
+     * Function converts the input in place in the passed variable so that it
+     * can be used as a callback for array_walk_recursive.
+     *
+     * @param mixed &$data Input to check and convert if needed
+     * @access private
+     */
+    public function detectAndCleanUtf8(&$data)
+    {
+        if (is_string($data) && !preg_match('//u', $data)) {
+            $data = preg_replace_callback(
+                '/[\x80-\xFF]+/',
+                function ($m) { return utf8_encode($m[0]); },
+                $data
+            );
+            $data = str_replace(
+                array('¤', '¦', '¨', '´', '¸', '¼', '½', '¾'),
+                array('€', 'Š', 'š', 'Ž', 'ž', 'Œ', 'œ', 'Ÿ'),
+                $data
+            );
+        }
+    }
 }