Do not use NamedTemporaryFile in handle_image_tempfile

As external program may not be able to reopen the temporary file.

See:
http://docs.python.org/library/tempfile.html#tempfile.NamedTemporaryFile

IPython/utils/tests/test_tempdir.py

@@ -0,0 +1,20 b''
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2012-  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+import os
+
+from IPython.utils.tempdir import NamedFileInTemporaryDirectory
+
+
+def test_named_file_in_temporary_directory():
+    with NamedFileInTemporaryDirectory('filename') as file:
+        name = file.name
+        assert not file.closed
+        assert os.path.exists(name)
+        file.write('test')
+    assert file.closed
+    assert not os.path.exists(name)

IPython/frontend/terminal/console/interactiveshell.py

@@ -22,7 +22,6 b' import signal'
 import os
 import sys
 import time
-import tempfile
 import subprocess
 from io import BytesIO
 import base64
@@ -39,6 +38,7 b' from IPython.core import page'
 from IPython.utils.warn import warn, error, fatal
 from IPython.utils import io
 from IPython.utils.traitlets import List, Enum, Any
+from IPython.utils.tempdir import NamedFileInTemporaryDirectory
 
 from IPython.frontend.terminal.interactiveshell import TerminalInteractiveShell
 from IPython.frontend.terminal.console.completer import ZMQCompleter
@@ -285,7 +285,7 b' class ZMQTerminalInteractiveShell(TerminalInteractiveShell):'
         raw = base64.decodestring(data[mime])
         imageformat = self._imagemime[mime]
         ext = '.{0}'.format(imageformat)
-        with nested(tempfile.NamedTemporaryFile(suffix=ext),
+        with nested(NamedFileInTemporaryDirectory('tmp.{0}'.format(ext)),
                     open(os.devnull, 'w')) as (f, devnull):
             f.write(raw)
             f.flush()

IPython/utils/tempdir.py

@@ -3,14 +3,14 b''
 This is copied from the stdlib and will be standard in Python 3.2 and onwards.
 """
 
+import os as _os
+
 # This code should only be used in Python versions < 3.2, since after that we
 # can rely on the stdlib itself.
 try:
     from tempfile import TemporaryDirectory
 
 except ImportError:
-    
-    import os as _os
     from tempfile import mkdtemp, template
 
     class TemporaryDirectory(object):
@@ -74,3 +74,33 b' except ImportError:'
                 self._rmdir(path)
             except self._os_error:
                 pass
+
+
+class NamedFileInTemporaryDirectory(object):
+
+    def __init__(self, filename, mode='w+b', bufsize=-1, **kwds):
+        """
+        Open a file named `filename` in a temporary directory.
+
+        This context manager is preferred over `NamedTemporaryFile` in
+        stdlib `tempfile` when one needs to reopen the file.
+
+        Arguments `mode` and `bufsize` are passed to `open`.
+        Rest of the arguments are passed to `TemporaryDirectory`.
+
+        """
+        self._tmpdir = TemporaryDirectory(**kwds)
+        path = _os.path.join(self._tmpdir.name, filename)
+        self.file = open(path, mode, bufsize)
+
+    def cleanup(self):
+        self.file.close()
+        self._tmpdir.cleanup()
+
+    __del__ = cleanup
+
+    def __enter__(self):
+        return self.file
+
+    def __exit__(self, type, value, traceback):
+        self.cleanup()