Fix auto-height issues for pages

Changed to calculate height based on real page width and image ratio

Author: etodanik

public/javascripts/DV/models/page.js

@@ -93,7 +93,11 @@ DV.model.Pages.prototype = {
   // Update the height for a page, when its real image has loaded.
   updateHeight: function(image, pageIndex) {
     var h = this.getPageHeight(pageIndex);
-    var height = image.height * (this.zoomLevel > this.BASE_WIDTH ? 0.7 : 1.0);
+    // we want to preserve the original image's ratio, but not it's literal height
+    var ratio = image.height / image.width;
+    // the height will be adjusted according to the real width of the page taking into account the original ratio
+    var height = this.width * ratio * (this.zoomLevel > this.BASE_WIDTH ? 0.7 : 1.0);
+    
     if (image.width < this.baseWidth) {
       // Not supposed to happen, but too-small images sometimes do.
       height *= (this.baseWidth / image.width);