diffs: store wide-diff mode in user sessions for saved state.

rhodecode/apps/home/views.py

@@ -743,4 +743,4 b' class HomeView(BaseAppView):'
         if existing_value != val:
             self.request.session[key] = val
 
-        return 'stored:{}'.format(key)
+        return 'stored:{}:{}'.format(key, val)

rhodecode/public/js/src/rhodecode/comments.js

@@ -587,12 +587,14 b' var CommentsController = function() {'
           $('#content').removeClass("wrapper");
           $('#content').addClass("wide-mode-wrapper");
           $(node).addClass('btn-success');
+          return true
       } else {
           $('#content').removeClass("wide-mode-wrapper");
           $('#content').addClass("wrapper");
           $(node).removeClass('btn-success');
+          return false
       }
-      return false;
+
   };
 
   this.toggleComments = function(node, show) {

rhodecode/templates/codeblocks/diffs.mako

@@ -959,7 +959,8 b' def get_comments_for(diff_type, comments'
                         text: _gettext('Toggle Wide Mode diff'),
                         action: function () {
                             updateSticky();
-                            Rhodecode.comments.toggleWideMode(this);
+                            var wide = Rhodecode.comments.toggleWideMode(this);
+                            storeUserSessionAttr('rc_user_session_attr.wide_diff_mode', wide);
                             return null;
                         },
                         url: null,
@@ -1002,6 +1003,11 b' def get_comments_for(diff_type, comments'
                 ]
             };
 
+            // get stored diff mode and pre-enable it
+            if (templateContext.session_attrs.wide_diff_mode === "true") {
+                Rhodecode.comments.toggleWideMode(null);
+            }
+
             $("#diff_menu").select2({
                 minimumResultsForSearch: -1,
                 containerCssClass: "drop-menu",