merge revision(s) 42720: [Backport #8829]

	* ext/zlib/zlib.c (zstream_run):  Fix handling of deflate streams that
	  need a dictionary but are being decompressed by Zlib::Inflate.inflate
	  (which has no option to set a dictionary).  Now Zlib::NeedDict is
	  raised instead of crashing.  [ruby-trunk - Bug #8829]

	* test/zlib/test_zlib.rb (TestZlibInflate):  Test for the above.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@42727 b2dd03c8-39d4-4d8f-98ff-823fe69b080e