3 files changed, 22 insertions, 1 deletions
diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index f6a40f62d1..1aa2d5b521 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Rewind request body after reading it, if possible.  #8438 [s450r1]
+
 * Resource namespaces are inherited by their has_many subresources.  #8280 [marclove, ggarside]
 
 * Fix filtered parameter logging with nil parameter values.  #8422 [choonkeat]
diff --git a/actionpack/lib/action_controller/request.rb b/actionpack/lib/action_controller/request.rb
index 0dfc4a91d0..476f65a6dc 100755
--- a/actionpack/lib/action_controller/request.rb
+++ b/actionpack/lib/action_controller/request.rb
@@ -330,7 +330,9 @@ module ActionController
 
         # Only multipart form parsing expects a stream.
         if strategy && strategy != :multipart_form
-          body = body.read(content_length)
+          data = body.read(content_length)
+          body.rewind if body.respond_to?(:rewind)
+          body = data
         end
 
         case strategy
diff --git a/actionpack/test/controller/cgi_test.rb b/actionpack/test/controller/cgi_test.rb
index 4c3fbc37c5..da3ca245e1 100755
--- a/actionpack/test/controller/cgi_test.rb
+++ b/actionpack/test/controller/cgi_test.rb
@@ -68,3 +68,20 @@ class CgiRequestParamsParsingTest < BaseCgiTest
     assert_equal({"flamenco"=> "love"}, @request.request_parameters)
   end
 end
+
+
+class CgiRequestNeedsRewoundTest < BaseCgiTest
+  def test_body_should_be_rewound
+    data = 'foo'
+    fake_cgi = Struct.new(:env_table, :query_string, :stdinput).new(@request_hash, '', StringIO.new(data))
+    fake_cgi.env_table['CONTENT_LENGTH'] = data.length
+    fake_cgi.env_table['CONTENT_TYPE'] = 'application/x-www-form-urlencoded; charset=utf-8'
+
+    # Read the request body by parsing params.
+    request = ActionController::CgiRequest.new(fake_cgi)
+    request.request_parameters
+
+    # Should have rewound the body.
+    assert_equal 0, request.body.pos
+  end
+end