From 94da8b17374a71b451e9b7f3b6e97ab058bdbc81 Mon Sep 17 00:00:00 2001
From: shugo <shugo@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 25 Nov 2015 01:57:48 +0000
Subject: [PATCH] * io.c (argf_getpartial): should not resize str if the second
   argument is not given.   [ruby-core:71668] [Bug #11738]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52745 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog              |  6 ++++++
 io.c                   |  4 +++-
 test/ruby/test_argf.rb | 11 +++++++++++
 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 99381a8881..25905864c6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Nov 25 10:55:21 2015  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* io.c (argf_getpartial): should not resize str if the second
+	  argument is not given.
+	  [ruby-core:71668] [Bug #11738]
+
 Tue Nov 24 23:56:25 2015  Naohisa Goto  <ngotogenome@gmail.com>
 
 	* configure.in: On Solaris, it is safe to define _LARGEFILE_SOURCE
diff --git a/io.c b/io.c
index 11b6499a41..9d75c230f4 100644
--- a/io.c
+++ b/io.c
@@ -11247,7 +11247,9 @@ argf_getpartial(int argc, VALUE *argv, VALUE argf, VALUE opts, int nonblock)
     }
 
     if (!next_argv()) {
-        rb_str_resize(str, 0);
+	if (!NIL_P(str)) {
+	    rb_str_resize(str, 0);
+	}
         rb_eof_error();
     }
     if (ARGF_GENERIC_INPUT_P()) {
diff --git a/test/ruby/test_argf.rb b/test/ruby/test_argf.rb
index cb27b9c64e..e40b038967 100644
--- a/test/ruby/test_argf.rb
+++ b/test/ruby/test_argf.rb
@@ -510,6 +510,17 @@ class TestArgf < Test::Unit::TestCase
     end
   end
 
+  def test_readpartial_eof_twice
+    ruby('-W1', '-e', <<-SRC, @t1.path) do |f|
+      $stderr = $stdout
+      print ARGF.readpartial(256)
+      ARGF.readpartial(256) rescue p($!.class)
+      ARGF.readpartial(256) rescue p($!.class)
+    SRC
+      assert_equal("1\n2\nEOFError\nEOFError\n", f.read)
+    end
+  end
+
   def test_getc
     ruby('-e', <<-SRC, @t1.path, @t2.path, @t3.path) do |f|
       s = ""