From a2ee820609765ca95dfad5803fd26da72b67a9c2 Mon Sep 17 00:00:00 2001
From: Alfred Xing <alfredxing@users.noreply.github.com>
Date: Tue, 19 May 2015 22:47:52 -0700
Subject: [PATCH] Regenerator: handle deleted/renamed/moved dependencies

Should fix #3716
---
 lib/jekyll/regenerator.rb |  2 +-
 test/test_regenerator.rb  | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/lib/jekyll/regenerator.rb b/lib/jekyll/regenerator.rb
index 8ddfa269..9b1dc67a 100644
--- a/lib/jekyll/regenerator.rb
+++ b/lib/jekyll/regenerator.rb
@@ -102,7 +102,7 @@ module Jekyll
             return cache[dependency] = cache[path] = true
           end
         end
-        if data["mtime"].eql? File.mtime(path)
+        if File.exist?(path) && data["mtime"].eql?(File.mtime(path))
           return cache[path] = false
         else
           return add(path)
diff --git a/test/test_regenerator.rb b/test/test_regenerator.rb
index 060fc524..eda25969 100644
--- a/test/test_regenerator.rb
+++ b/test/test_regenerator.rb
@@ -89,6 +89,41 @@ class TestRegenerator < JekyllUnitTest
     end
   end
 
+  context "The site regenerator" do
+    setup do
+      FileUtils.rm_rf(source_dir(".jekyll-metadata"))
+
+      @site = fixture_site({
+        "full_rebuild" => false
+      })
+
+      @site.read
+      @post = @site.posts.first
+      @regenerator = @site.regenerator
+      @regenerator.regenerate?(@post)
+
+      @layout_path = source_dir("_layouts/default.html")
+    end
+
+    teardown do
+      File.rename(@layout_path + ".tmp", @layout_path)
+    end
+
+    should "handle deleted/nonexistent dependencies" do
+      assert_equal 1, @regenerator.metadata.size
+      path = @regenerator.metadata.keys[0]
+
+      assert File.exist?(@layout_path)
+      @regenerator.add_dependency(path, @layout_path)
+
+      File.rename(@layout_path, @layout_path + ".tmp")
+      refute File.exist?(@layout_path)
+
+      @regenerator.clear_cache
+      assert @regenerator.regenerate?(@post)
+    end
+  end
+
   context "The site metadata" do
     setup do
       FileUtils.rm_rf(source_dir(".jekyll-metadata"))