3 files changed, 36 insertions, 2 deletions
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 8153dd57de..df35540b55 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -58,7 +58,14 @@ module ActiveSupport
       case store
       when Symbol
         store_class_name = store.to_s.camelize
-        store_class = ActiveSupport::Cache.const_get(store_class_name)
+        store_class =
+          begin
+            require "active_support/cache/#{store}"
+          rescue LoadError
+            raise "Could not find cache store adapter for #{store} (#{$!})"
+          else
+            ActiveSupport::Cache.const_get(store_class_name)
+          end
         store_class.new(*parameters)
       when nil
         ActiveSupport::Cache::MemoryStore.new
diff --git a/activesupport/lib/active_support/core_ext/string.rb b/activesupport/lib/active_support/core_ext/string.rb
index d8d1f9436e..8fb8c31ade 100644
--- a/activesupport/lib/active_support/core_ext/string.rb
+++ b/activesupport/lib/active_support/core_ext/string.rb
@@ -9,4 +9,5 @@ require 'active_support/core_ext/string/behavior'
 require 'active_support/core_ext/string/interpolation'
 require 'active_support/core_ext/string/output_safety'
 require 'active_support/core_ext/string/exclude'
-require 'active_support/core_ext/string/encoding'
-\ No newline at end of file
+require 'active_support/core_ext/string/encoding'
+require 'active_support/core_ext/string/strip'
diff --git a/activesupport/lib/active_support/core_ext/string/strip.rb b/activesupport/lib/active_support/core_ext/string/strip.rb
new file mode 100644
index 0000000000..086c610976
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/string/strip.rb
@@ -0,0 +1,26 @@
+require 'active_support/core_ext/object/try'
+
+class String
+  # Strips indentation in heredocs.
+  #
+  # For example in
+  #
+  #   if options[:usage]
+  #     puts <<-USAGE.strip_heredoc
+  #       This command does such and such.
+  #
+  #       Supported options are:
+  #         -h         This message
+  #         ...
+  #     USAGE
+  #   end
+  #
+  # the user would see the usage message aligned against the left margin.
+  #
+  # Technically, it looks for the least indented line in the whole string, and removes
+  # that amount of leading whitespace.
+  def strip_heredoc
+    indent = scan(/^[ \t]*(?=\S)/).min.try(:size) || 0
+    gsub(/^[ \t]{#{indent}}/, '')
+  end
+end