From 9010274627a538c688e44737e7a50c659da7e863 Mon Sep 17 00:00:00 2001
From: Adam Panzer <apanzerj@gmail.com>
Date: Tue, 10 Jun 2014 10:53:48 -0700
Subject: [PATCH] fix error with long keys in ActiveSupport::Cache::FileStore

---
 activesupport/CHANGELOG.md                           | 3 +++
 activesupport/lib/active_support/cache/file_store.rb | 5 +++++
 activesupport/test/caching_test.rb                   | 5 +++++
 3 files changed, 13 insertions(+)

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index 871e1705f7..5962dd255c 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,6 @@
+*   Fixed `ActiveSupport::Cache::FileStore` exploding with long paths.
+    *Adam Panzer / Michael Grosser* 
+
 *   Fixed `ActiveSupport::TimeWithZone#-` so precision is not unnecessarily lost
     when working with objects with a nanosecond component.
 
diff --git a/activesupport/lib/active_support/cache/file_store.rb b/activesupport/lib/active_support/cache/file_store.rb
index 8ed60aebac..d08ecd2f7d 100644
--- a/activesupport/lib/active_support/cache/file_store.rb
+++ b/activesupport/lib/active_support/cache/file_store.rb
@@ -14,6 +14,7 @@ module ActiveSupport
 
       DIR_FORMATTER = "%03X"
       FILENAME_MAX_SIZE = 228 # max filename size on file system is 255, minus room for timestamp and random characters appended by Tempfile (used by atomic write)
+      FILEPATH_MAX_SIZE = 900 # max is 1024, plus some room
       EXCLUDED_DIRS = ['.', '..'].freeze
 
       def initialize(cache_path, options = nil)
@@ -117,6 +118,10 @@ module ActiveSupport
 
         # Translate a key into a file path.
         def key_file_path(key)
+          if key.size > FILEPATH_MAX_SIZE
+            key = Digest::MD5.hexdigest(key)
+          end
+
           fname = URI.encode_www_form_component(key)
           hash = Zlib.adler32(fname)
           hash, dir_1 = hash.divmod(0x1000)
diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb
index 18923f61d1..d55cc5d3b0 100644
--- a/activesupport/test/caching_test.rb
+++ b/activesupport/test/caching_test.rb
@@ -692,6 +692,11 @@ class FileStoreTest < ActiveSupport::TestCase
     assert File.exist?(filepath)
   end
 
+  def test_long_keys
+    @cache.write("a"*10000, 1)
+    assert_equal 1, @cache.read("a"*10000)
+  end
+
   def test_key_transformation
     key = @cache.send(:key_file_path, "views/index?id=1")
     assert_equal "views/index?id=1", @cache.send(:file_path_key, key)