[rubygems/rubygems] Add TarReader::Entry#seek to seek within the tar file entry

TarReader#each previously implemented a partial version of seek.
This code moved to Entry#seek for use from TarReader#each.

Entry#close now returns nil instead of true, like IO#close.

Closing an Entry now seeks to the end of the Entry, seeking past
any remaining zero byte tar file padding and moving the io to the
correcty position to read the next file in the archive.

Uses seek for Entry#rewind and #pos=, fixing the tar->gzip->tar nested
rewind that would break previous to this change.

Add Entry.open that behaves more like File.open.

https://github.com/rubygems/rubygems/commit/f5149565d5

1 files changed, 48 insertions, 1 deletions

diff --git a/test/rubygems/test_gem_package_tar_reader.rb b/test/rubygems/test_gem_package_tar_reader.rb
index 19860eb7e8..62e60489a6 100644
--- a/test/rubygems/test_gem_package_tar_reader.rb
+++ b/test/rubygems/test_gem_package_tar_reader.rb
@@ -56,12 +56,14 @@ class TestGemPackageTarReader < Gem::Package::TarTestCase
     io = TempIO.new tar
 
     Gem::Package::TarReader.new io do |tar_reader|
-      tar_reader.seek "baz/bar" do |entry|
+      retval = tar_reader.seek "baz/bar" do |entry|
         assert_kind_of Gem::Package::TarReader::Entry, entry
 
         assert_equal "baz/bar", entry.full_name
+        entry.read
       end
 
+      assert_equal "", retval
       assert_equal 0, io.pos
     end
   ensure
@@ -84,4 +86,49 @@ class TestGemPackageTarReader < Gem::Package::TarTestCase
   ensure
     io.close!
   end
+
+  def test_read_in_gem_data
+    gem_tar = util_gem_data_tar do |tar|
+      tar.add_file "lib/code.rb", 0444 do |io|
+        io.write "# lib/code.rb"
+      end
+    end
+
+    count = 0
+    Gem::Package::TarReader.new(gem_tar).each do |entry|
+      next unless entry.full_name == "data.tar.gz"
+
+      Zlib::GzipReader.wrap entry do |gzio|
+        Gem::Package::TarReader.new(gzio).each do |contents_entry|
+          assert_equal "# lib/code.rb", contents_entry.read
+          count += 1
+        end
+      end
+    end
+
+    assert_equal 1, count, "should have found one file"
+  end
+
+  def test_seek_in_gem_data
+    gem_tar = util_gem_data_tar do |tar|
+      tar.add_file "lib/code.rb", 0444 do |io|
+        io.write "# lib/code.rb"
+      end
+      tar.add_file "lib/foo.rb", 0444 do |io|
+        io.write "# lib/foo.rb"
+      end
+    end
+
+    count = 0
+    Gem::Package::TarReader.new(gem_tar).seek("data.tar.gz") do |entry|
+      Zlib::GzipReader.wrap entry do |gzio|
+        Gem::Package::TarReader.new(gzio).seek("lib/foo.rb") do |contents_entry|
+          assert_equal "# lib/foo.rb", contents_entry.read
+          count += 1
+        end
+      end
+    end
+
+    assert_equal 1, count, "should have found one file"
+  end
 end