merge revision(s) r46360,r46372: [Backport #8625]

	* io.c (io_setstrbuf, io_read): should not shorten the given buffer until
	  read succeeds.  [ruby-core:55951] [Bug #8625]

	* io.c (read_all): truncate the buffer before appending read data,
	  instead of truncating before reading.
	  [ruby-core:55951] [Bug #8625]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@46629 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 21 insertions, 0 deletions

diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 115a498474..a7c5b2a39a 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1224,6 +1224,14 @@ class TestIO < Test::Unit::TestCase
       t.value
       assert_equal("", s)
     end
+    with_pipe do |r, w|
+      s = "xxx"
+      t = Thread.new {r.read(2, s)}
+      Thread.pass until t.stop?
+      t.kill
+      t.value
+      assert_equal("xxx", s)
+    end
   end
 
   def test_write_nonblock
diff --git a/test/ruby/test_pipe.rb b/test/ruby/test_pipe.rb
index 34f231ad8c..bcea91bebb 100644
--- a/test/ruby/test_pipe.rb
+++ b/test/ruby/test_pipe.rb
@@ -13,4 +13,17 @@ class TestPipe < Test::Unit::TestCase
       r.close
     end
   end
+  class WithConversion < self
+    def open_file(content)
+      r, w = IO.pipe
+      w << content
+      w.close
+      r.set_encoding("us-ascii:utf-8")
+      begin
+        yield r
+      ensure
+        r.close
+      end
+    end
+  end
 end