* io.c (io_readpartial): Document the output buffer parameter is

  overwritten with the read contents even when non-empty.
  Patch by yu nobuoka.  [ruby-trunk - Bug #6285]
* io.c (io_read_nonblock):  ditto.
* io.c (io_read):  ditto.
* io.c (rb_io_sysread):  ditto.
* io.c (argf_read):  ditto.
* io.c (argf_readpartial):  ditto.
* ext/stringio/stringio.c (strio_read):  ditto.
* test/ruby/test_argf.rb (class TestArgf):  Add test for existing
  behavior of read outbuf.
* test/ruby/test_io.rb (class TestIO):  ditto.
* test/stringio/test_stringio.rb (class TestStringIO):  ditto.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35391 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 66 insertions, 0 deletions

diff --git a/test/ruby/test_argf.rb b/test/ruby/test_argf.rb
index 2f1ddf5391..284f34259e 100644
--- a/test/ruby/test_argf.rb
+++ b/test/ruby/test_argf.rb
@@ -446,6 +446,16 @@ class TestArgf < Test::Unit::TestCase
     end
   end
 
+  def test_read2_with_not_empty_buffer
+    ruby('-e', <<-SRC, @t1.path, @t2.path, @t3.path) do |f|
+      s = "0123456789"
+      ARGF.read(8, s)
+      p s
+    SRC
+      assert_equal("\"1\\n2\\n3\\n4\\n\"\n", f.read)
+    end
+  end
+
   def test_read3
     ruby('-e', <<-SRC, @t1.path, @t2.path, @t3.path) do |f|
       nil while ARGF.gets
@@ -463,6 +473,8 @@ class TestArgf < Test::Unit::TestCase
         loop do
           s << ARGF.readpartial(1)
           t = ""; ARGF.readpartial(1, t); s << t
+          # not empty buffer
+          u = "abcdef"; ARGF.readpartial(1, u); s << u
         end
       rescue EOFError
         puts s
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 0f4d5234a0..d984252cb5 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -991,6 +991,16 @@ class TestIO < Test::Unit::TestCase
     }
   end
 
+  def test_readpartial_with_not_empty_buffer
+    pipe(proc do |w|
+      w.write "foob"
+      w.close
+    end, proc do |r|
+      r.readpartial(5, s = "01234567")
+      assert_equal("foob", s)
+    end)
+  end
+
   def test_readpartial_buffer_error
     with_pipe do |r, w|
       s = ""
@@ -1026,6 +1036,16 @@ class TestIO < Test::Unit::TestCase
     end
   end
 
+  def test_read_with_not_empty_buffer
+    pipe(proc do |w|
+      w.write "foob"
+      w.close
+    end, proc do |r|
+      r.read(nil, s = "01234567")
+      assert_equal("foob", s)
+    end)
+  end
+
   def test_read_buffer_error
     with_pipe do |r, w|
       s = ""
@@ -1047,6 +1067,17 @@ class TestIO < Test::Unit::TestCase
     end)
   end
 
+  def test_read_nonblock_with_not_empty_buffer
+    skip "IO#read_nonblock is not supported on file/pipe." if /mswin|bccwin|mingw/ =~ RUBY_PLATFORM
+    pipe(proc do |w|
+      w.write "foob"
+      w.close
+    end, proc do |r|
+      r.read_nonblock(5, s = "01234567")
+      assert_equal("foob", s)
+    end)
+  end
+
   def test_read_nonblock_error
     return if !have_nonblock?
     skip "IO#read_nonblock is not supported on file/pipe." if /mswin|bccwin|mingw/ =~ RUBY_PLATFORM
@@ -1417,6 +1448,16 @@ class TestIO < Test::Unit::TestCase
     end
   end
 
+  def test_sysread_with_not_empty_buffer
+    pipe(proc do |w|
+      w.write "foob"
+      w.close
+    end, proc do |r|
+      r.sysread( 5, s = "01234567" )
+      assert_equal( "foob", s )
+    end)
+  end
+
   def test_flag
     t = make_tempfile
 
diff --git a/test/stringio/test_stringio.rb b/test/stringio/test_stringio.rb
index 26fcc624e2..22cba382fb 100644
--- a/test/stringio/test_stringio.rb
+++ b/test/stringio/test_stringio.rb
@@ -426,6 +426,11 @@ class TestStringIO < Test::Unit::TestCase
     s = ""
     f.read(nil, s)
     assert_equal("\u3042\u3044", s, bug5207)
+    f.rewind
+    # not empty buffer
+    s = "0123456789"
+    f.read(nil, s)
+    assert_equal("\u3042\u3044", s)
   end
 
   def test_readpartial
@@ -435,6 +440,10 @@ class TestStringIO < Test::Unit::TestCase
     assert_equal("\u3042\u3044", f.readpartial)
     f.rewind
     assert_equal("\u3042\u3044".force_encoding(Encoding::ASCII_8BIT), f.readpartial(f.size))
+    f.rewind
+    # not empty buffer
+    s = '0123456789'
+    assert_equal("\u3042\u3044".force_encoding(Encoding::ASCII_8BIT), f.readpartial(f.size, s))
   end
 
   def test_read_nonblock
@@ -444,6 +453,10 @@ class TestStringIO < Test::Unit::TestCase
     assert_equal("\u3042\u3044", f.read_nonblock)
     f.rewind
     assert_equal("\u3042\u3044".force_encoding(Encoding::ASCII_8BIT), f.read_nonblock(f.size))
+    f.rewind
+    # not empty buffer
+    s = '0123456789'
+    assert_equal("\u3042\u3044".force_encoding(Encoding::ASCII_8BIT), f.read_nonblock(f.size, s))
   end
 
   def test_size