BUG: redirector_output_trap was not closing properly the stdout.

IPython/kernel/core/redirector_output_trap.py

@@ -1,93 +1,93 b''
 # encoding: utf-8
 
 """ 
 Trap stdout/stderr, including at the OS level. Calls a callback with
 the output each time Python tries to write to the stdout or stderr.
 """
 
 __docformat__ = "restructuredtext en"
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2008  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.
 #-------------------------------------------------------------------------------
 
 #-------------------------------------------------------------------------------
 # Imports
 #-------------------------------------------------------------------------------
 
 from fd_redirector import FDRedirector, STDOUT, STDERR
 
 from IPython.kernel.core.file_like import FileLike
 from IPython.kernel.core.output_trap import OutputTrap
 
 class RedirectorOutputTrap(OutputTrap):
     """ Object which can trap text sent to stdout and stderr.
     """
 
     #------------------------------------------------------------------------
     # OutputTrap interface.
     #------------------------------------------------------------------------
     def __init__(self, out_callback, err_callback):
         # Callback invoked on write to stdout and stderr 
         self.out_callback = out_callback
         self.err_callback = err_callback
 
         # File descriptor redirectors, to capture non-Python
         # output.
         self.out_redirector = FDRedirector(STDOUT)
         self.err_redirector = FDRedirector(STDERR)
 
         # Call the base class with file like objects that will trigger
         # our callbacks
         OutputTrap.__init__(self, out=FileLike(self.on_out_write),
                                   err=FileLike(self.on_err_write), )
 
 
     def set(self):
         """ Set the hooks: set the redirectors and call the base class.
         """
         self.out_redirector.start()
-        #self.err_redirector.start()
+        self.err_redirector.start()
         OutputTrap.set(self)
 
 
     def unset(self):
         """ Remove the hooks: call the base class and stop the
             redirectors.
         """
         OutputTrap.unset(self)
         # Flush the redirectors before stopping them
-        self.on_out_write('')
-        self.err_redirector.stop()
         self.on_err_write('')
+        self.err_redirector.stop()
+        self.on_out_write('')
         self.out_redirector.stop()
 
 
     #------------------------------------------------------------------------
     # Callbacks for synchronous output 
     #------------------------------------------------------------------------
     def on_out_write(self, string):
         """ Callback called when there is some Python output on stdout.
         """
         try:
             self.out_callback(self.out_redirector.getvalue() + string)
         except:
             # If tracebacks are happening and we can't see them, it is
             # quasy impossible to debug
             self.unset()
             raise
 
     def on_err_write(self, string):
         """ Callback called when there is some Python output on stderr.
         """
         try:
             self.err_callback(self.err_redirector.getvalue() + string)
         except:
             # If tracebacks are happening and we can't see them, it is
             # quasy impossible to debug
             self.unset()
             raise
 

IPython/kernel/core/tests/test_redirectors.py

@@ -1,50 +1,81 b''
+# encoding: utf-8
+
 """
 Test the output capture at the OS level, using file descriptors.
 """
 
+__docformat__ = "restructuredtext en"
+
+#---------------------------------------------------------------------------
+#  Copyright (C) 2008  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 cStringIO import StringIO
+import sys
 
 
 def test_redirector():
     """ Checks that the redirector can be used to do synchronous capture.
     """
+    # Flush the stdout, so as not to have side effects between
+    # tests.
+    sys.stdout.flush()
+    sys.stderr.flush()
     from IPython.kernel.core.fd_redirector import FDRedirector
     r = FDRedirector()
     out = StringIO()
     try:
         r.start()
         for i in range(10):
             os.system('echo %ic' % i)
             print >>out, r.getvalue(),
             print >>out, i
     except:
         r.stop()
         raise
     r.stop()
     assert out.getvalue() == "".join("%ic\n%i\n" %(i, i) for i in range(10))
+    sys.stdout.flush()
+    sys.stderr.flush()
 
 
 def test_redirector_output_trap():
     """ This test check not only that the redirector_output_trap does
         trap the output, but also that it does it in a gready way, that
-        is by calling the callabck ASAP.
+        is by calling the callback ASAP.
     """
+    # Flush the stdout, so as not to have side effects between
+    # tests.
+    sys.stdout.flush()
+    sys.stderr.flush()
     from IPython.kernel.core.redirector_output_trap import RedirectorOutputTrap
     out = StringIO()
     trap = RedirectorOutputTrap(out.write, out.write)
     try:
         trap.set()
         for i in range(10):
             os.system('echo %ic' % i)
             print "%ip" % i
             print >>out, i
     except:
         trap.unset()
         raise
     trap.unset()
+    sys.stdout.flush()
+    sys.stderr.flush()
     assert out.getvalue() == "".join("%ic\n%ip\n%i\n" %(i, i, i) 
                                                     for i in range(10))
 
-    
+
+
+if __name__ == '__main__':
+    print "Testing redirector...",
+    test_redirector()
+    test_redirector_output_trap()
+    print "Done."