问题跟踪附件图片显示不拉伸

app/views/attachments/_project_file_links.html.erb

@@ -1,23 +1,49 @@
 <script type="text/javascript">
     document.addEventListener('DOMContentLoaded',function(){
         var img = document.getElementsByName('issue_attachment_picture');
-        function getImgNaturalStyle(img,callback) {
-            var nWidth, nHeight
-            if (typeof img.naturalWidth == "undefined"|| img.naturalWidth == 0) { // 现代浏览器
+
+
+        function getImgNaturalStyle(img, callback) {
+            var nWidth, nHeight;
+            if (typeof img.naturalWidth == "undefined"|| img.naturalWidth == 0) {
                 var image = new Image();
                 image.src = img.src;
-                nWidth = image.width;
-                nHeight = image.height;
-            } else {
-                nWidth = img.naturalWidth;
-                nHeight = img.naturalHeight;
+                if (image.complete) {
+                    callback(image);
+                } else {
+                    image.onload = function () {
+                        callback(image);
+                        image.onload = null;
+                    };
+                };
+
             }
-            return [nWidth, nHeight]
+            else
+            {
+                if (img.complete) {
+                    nWidth = img.naturalWidth;
+                    nHeight = img.naturalHeight;
+                } else {
+                    img.onload = function () {
+                        nWidth = img.naturalWidth;
+                        nHeight = img.naturalHeight;
+                        image.onload = null;
+                    };
+                };
+
+            }
+            return [nWidth, nHeight];
         }
 
+
+        function UpdateImageInformation(image) {
+            return [image.width,image.height];
+        }
+
+
         for(i=0;i<img.length;i++)
         {
-            imgNatural = getImgNaturalStyle(img[i]);
+            imgNatural = getImgNaturalStyle(img[i],UpdateImageInformation);
             var width = imgNatural[0];
             var height = imgNatural[1];
             if (width<100)
@@ -29,7 +55,10 @@
             }
         }
     });
+
+
 </script>
+
 <div class="attachments" style="font-weight:normal;">
   <% is_float ||= false %>
   <% for attachment in attachments %>