MR: Handle broken diff ex. in case its too huge

app/models/merge_request.rb

@@ -3,6 +3,8 @@ require File.join(Rails.root, "app/models/commit")
 class MergeRequest < ActiveRecord::Base
   include Upvote
 
+  BROKEN_DIFF = "--broken-diff"
+
   UNCHECKED = 1
   CAN_BE_MERGED = 2
   CANNOT_BE_MERGED = 3
@@ -108,14 +110,25 @@ class MergeRequest < ActiveRecord::Base
   def reloaded_diffs
     if open? && unmerged_diffs.any?
       self.st_diffs = unmerged_diffs
-      save
+      self.save
     end
-    diffs
+
+  rescue Grit::Git::GitTimeout
+    self.st_diffs = [BROKEN_DIFF]
+    self.save
+  end
+
+  def broken_diffs?
+    diffs == [BROKEN_DIFF]
+  end
+
+  def valid_diffs?
+    !broken_diffs?
   end
 
   def unmerged_diffs
     commits = project.repo.commits_between(target_branch, source_branch).map {|c| Commit.new(c)}
-    diffs = project.repo.diff(commits.first.prev_commit.id, commits.last.id) rescue []
+    diffs = project.repo.diff(commits.first.prev_commit.id, commits.last.id)
   end
 
   def last_commit

app/views/layouts/_project_menu.html.haml

@@ -13,24 +13,25 @@
       %li{:class => tab_class(:network)}
         = link_to "Network", graph_project_path(@project)
 
-    - if @project.issues_enabled
-      %li{:class => tab_class(:issues)}
-        = link_to  project_issues_filter_path(@project)  do
-          Issues
-          %span.count= @project.issues.opened.count
+  - if @project.issues_enabled
+    %li{:class => tab_class(:issues)}
+      = link_to  project_issues_filter_path(@project)  do
+        Issues
+        %span.count= @project.issues.opened.count
 
+  - if @project.repo_exists?
     - if @project.merge_requests_enabled
       %li{:class => tab_class(:merge_requests)}
         = link_to project_merge_requests_path(@project) do
           Merge Requests
           %span.count= @project.merge_requests.opened.count
 
-    - if @project.wall_enabled
-      %li{:class =>  tab_class(:wall)}
-        = link_to wall_project_path(@project) do
-          Wall
+  - if @project.wall_enabled
+    %li{:class =>  tab_class(:wall)}
+      = link_to wall_project_path(@project) do
+        Wall
 
-    - if @project.wiki_enabled
-      %li{:class =>  tab_class(:wiki)}
-        = link_to project_wiki_path(@project, :index) do
-          Wiki
+  - if @project.wiki_enabled
+    %li{:class =>  tab_class(:wiki)}
+      = link_to project_wiki_path(@project, :index) do
+        Wiki

app/views/merge_requests/show/_diffs.html.haml

-= render "commits/diffs", :diffs => @diffs
-- if @diffs.empty?
-  %p.cgray Nothing to merge
+- if @merge_request.valid_diffs?
+  = render "commits/diffs", :diffs => @diffs
+- elsif @merge_request.broken_diffs?
+  %h4.nothing_here_message 
+    Can't load diff.
+    You can #{link_to "download MR patch", raw_project_merge_request_path(@project, @merge_request), :class => "vlink"} instead.
+- else
+  %h4.nothing_here_message Nothing to merge