* ext/zlib/zlib.c: Zlib::GzipReader#read(0) returns "" instead of nil.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@6739 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Sat Aug  7 00:50:01 2004  Tanaka Akira  <akr@m17n.org>
+
+	* ext/zlib/zlib.c: Zlib::GzipReader#read(0) returns "" instead of nil.
+
 Mon Aug  3 13:49:12 2004  Hidetoshi NAGAI  <nagai@ai.kyutech.ac.jp>
 
 	* ext/tk/lib/tk/namespace.rb: bug fix

ext/zlib/zlib.c

@@ -2075,7 +2075,10 @@ gzfile_read(gz, len)
 {
     VALUE dst;
 
-    if (len <= 0) return Qnil;
+    if (len < 0)
+        rb_raise(rb_eArgError, "negative length %d given", len);
+    if (len == 0)
+	return rb_str_new(0, 0);
     while (!ZSTREAM_IS_FINISHED(&gz->z) && gz->z.buf_filled < len) {
 	gzfile_read_more(gz);
     }

test/zlib/test_zlib.rb

@@ -1,5 +1,6 @@
 require 'test/unit/testsuite'
 require 'test/unit/testcase'
+require 'stringio'
 
 begin
   require 'zlib'
@@ -7,6 +8,13 @@ rescue LoadError
 end
 
 if defined? Zlib
+  class TestZlibGzipReader < Test::Unit::TestCase
+    D0 = "\037\213\010\000S`\017A\000\003\003\000\000\000\000\000\000\000\000\000"
+    def test_read0
+      assert_equal("", Zlib::GzipReader.new(StringIO.new(D0)).read(0))
+    end
+  end
+
   class TestZlibGzipWriter < Test::Unit::TestCase
     def test_invalid_new
       # [ruby-dev:23228]