* string.c: add internal API rb_str_locktmp_ensure().

* io.c (io_fread): use rb_str_locktmp_ensure().
  [ruby-core:56121] [Bug #8669]

* test/ruby/test_io.rb: add a test for above.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42212 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 14 insertions, 0 deletions

diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 469498cb0c..55e034e3a1 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -2801,4 +2801,18 @@ End
       end
     }
   end if /mswin|mingw/ =~ RUBY_PLATFORM
+
+  def test_read_unlocktmp_ensure
+    bug8669 = '[ruby-core:56121] [Bug #8669]'
+
+    str = ""
+    r, = IO.pipe
+    t = Thread.new { r.read(nil, str) }
+    sleep 0.1 until t.stop?
+    t.raise
+    sleep 0.1 while t.alive?
+    assert_nothing_raised(RuntimeError, bug8669) { str.clear }
+  ensure
+    t.kill
+  end
 end