[RFC] resolve a recursion bug in ObjectHash#deref!

lib/pdf/reader/object_hash.rb

@@ -109,9 +109,6 @@ def deref!(key)
             hash[k] = deref!(value)
           end
         }
-      when PDF::Reader::Stream
-        object.hash = deref!(object.hash)
-        object
       when Array
         object.map { |value| deref!(value) }
       else

spec/integration_spec.rb

@@ -214,6 +214,16 @@
     end
   end
 
+  context "PDF that has a Form XObjects that references itself" do
+    let(:filename) { pdf_spec_file("form_xobject_recursive") }
+
+    it "extracts text correctly" do
+      PDF::Reader.open(filename) do |reader|
+        expect(reader.page(1).text).to include("this form XObject contains a reference to itself")
+      end
+    end
+  end
+
   context "PDF that uses multiple content streams for a single page" do
     let(:filename) { pdf_spec_file("split_params_and_operator") }
 

spec/integrity.yml

@@ -134,6 +134,9 @@ data/form_xobject.pdf:
 data/form_xobject_more.pdf:
   :bytes: 22055
   :md5: 1fcbd5a3f7429dd224871d8d9d7830a7
+data/form_xobject_recursive.pdf:
+  :bytes: 1454
+  :md5: 24cbbe4f91c23b37f9a1ddac81bd3a39
 data/hard_lock_under_osx.pdf:
   :bytes: 4545
   :md5: 365e2076036b5e2445d1dcde13d6dbb6

spec/object_hash_spec.rb

@@ -102,11 +102,6 @@
         PDF::Reader::Stream
     end
 
-    it "recursively dereferences references within stream hashes" do
-      font_file = hash.deref! PDF::Reader::Reference.new(15, 0)
-      expect(font_file.hash[:Length]).to eq 2103
-    end
-
     it "recursively dereferences references within arrays" do
       font = hash.deref! PDF::Reader::Reference.new(19, 0)
       expect(font[:DescendantFonts][0][:Subtype]).to eq :CIDFontType0