* io.c (io_reopen): unread current buffer before telling the

  position, for the case of reopening same file.  [ruby-dev:39479]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25348 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 21 insertions, 7 deletions

diff --git a/ChangeLog b/ChangeLog
index b7fd03cef4..1b63e1d1d2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Oct 15 14:57:58 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* io.c (io_reopen): unread current buffer before telling the
+	  position, for the case of reopening same file.  [ruby-dev:39479]
+
 Thu Oct 15 14:20:58 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/iconv/iconv.c (iconv_create): cannot retry with given block.
diff --git a/io.c b/io.c
index 9b0aadfda8..ccec1601dc 100644
--- a/io.c
+++ b/io.c
@@ -5654,13 +5654,6 @@ io_reopen(VALUE io, VALUE nfile)
 		     rb_io_fmode_modestr(orig->mode));
 	}
     }
-    if (orig->mode & FMODE_READABLE) {
-	pos = io_tell(orig);
-    }
-    if (orig->mode & FMODE_WRITABLE) {
-        if (io_fflush(orig) < 0)
-            rb_sys_fail(0);
-    }
     if (fptr->mode & FMODE_WRITABLE) {
         if (io_fflush(fptr) < 0)
             rb_sys_fail(0);
@@ -5668,6 +5661,13 @@ io_reopen(VALUE io, VALUE nfile)
     else {
 	io_tell(fptr);
     }
+    if (orig->mode & FMODE_READABLE) {
+	pos = io_tell(orig);
+    }
+    if (orig->mode & FMODE_WRITABLE) {
+        if (io_fflush(orig) < 0)
+            rb_sys_fail(0);
+    }
 
     /* copy rb_io_t structure */
     fptr->mode = orig->mode | (fptr->mode & FMODE_PREP);
diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 8b1714b01e..71f31e37a3 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1286,6 +1286,15 @@ class TestIO < Test::Unit::TestCase
         assert_equal("bar\n", f.gets, '[ruby-core:24240]')
       }
     end
+
+    open(__FILE__) do |f|
+      f2 = open(t.path)
+      f.reopen(f2)
+      assert_equal("foo\n", f.gets)
+      assert_equal("bar\n", f.gets)
+      f.reopen(f2)
+      assert_equal("baz\n", f.gets, '[ruby-dev:39479]')
+    end
   end
 
   def test_foreach