cJSON_Parse{,WithOpts}: Skip UTF-8 (Byte Order Marks)

cJSON.c

@@ -958,6 +958,22 @@ static parse_buffer *buffer_skip_whitespace(parse_buffer * const buffer)
     return buffer;
 }
 
+/* skip the UTF-8 BOM (byte order mark) if it is at the beginning of a buffer */
+static parse_buffer *skip_utf8_bom(parse_buffer * const buffer)
+{
+    if ((buffer == NULL) || (buffer->content == NULL) || (buffer->offset != 0))
+    {
+        return NULL;
+    }
+
+    if (can_access_at_index(buffer, 4) && (strncmp((const char*)buffer_at_offset(buffer), "\xEF\xBB\xBF", 3) == 0))
+    {
+        buffer->offset += 3;
+    }
+
+    return buffer;
+}
+
 /* Parse an object - create a new root, and populate. */
 CJSON_PUBLIC(cJSON *) cJSON_ParseWithOpts(const char *value, const char **return_parse_end, cJSON_bool require_null_terminated)
 {
@@ -984,7 +1000,7 @@ CJSON_PUBLIC(cJSON *) cJSON_ParseWithOpts(const char *value, const char **return
         goto fail;
     }
 
-    if (!parse_value(item, buffer_skip_whitespace(&buffer)))
+    if (!parse_value(item, buffer_skip_whitespace(skip_utf8_bom(&buffer))))
     {
         /* parse failure. ep is set. */
         goto fail;
@@ -1222,7 +1238,6 @@ static cJSON_bool parse_value(cJSON * const item, parse_buffer * const input_buf
         return parse_object(item, input_buffer);
     }
 
-
     return false;
 }