[ruby/zlib] Add Zlib::GzipReader.zcat for handling multiple gzip streams in gz file

Most gzip tools support concatenated gz streams in a gz file. This
offers a way to handle such gz files in Ruby.

Fixes [Bug #9790]
Fixes [Bug #11180]
Fixes [Bug #14804]

https://github.com/ruby/zlib/commit/e2ce56de7d

1 files changed, 24 insertions, 0 deletions

diff --git a/test/zlib/test_zlib.rb b/test/zlib/test_zlib.rb
index 7d703d15e4..c58eafe112 100644
--- a/test/zlib/test_zlib.rb
+++ b/test/zlib/test_zlib.rb
@@ -446,6 +446,30 @@ if defined? Zlib
   end
 
   class TestZlibGzipFile < Test::Unit::TestCase
+    def test_gzip_reader_zcat
+      Tempfile.create("test_zlib_gzip_file_to_io") {|t|
+        gz = Zlib::GzipWriter.new(t)
+        gz.print("foo")
+        gz.close
+        t = File.open(t.path, 'ab')
+        gz = Zlib::GzipWriter.new(t)
+        gz.print("bar")
+        gz.close
+
+        results = []
+        t = File.open(t.path)
+        Zlib::GzipReader.zcat(t) do |str|
+          results << str
+        end
+        assert_equal(["foo", "bar"], results)
+        t.close
+
+        t = File.open(t.path)
+        assert_equal("foobar", Zlib::GzipReader.zcat(t))
+        t.close
+      }
+    end
+
     def test_to_io
       Tempfile.create("test_zlib_gzip_file_to_io") {|t|
         t.close