Ensure that, with autocall off, attribute access will never be performed

twice (which can cause side effects).

IPython/iplib.py

@@ -6,7 +6,7 b' Requires Python 2.1 or newer.'
 
 This file contains all the classes and helper functions specific to IPython.
 
-$Id: iplib.py 975 2005-12-29 23:50:22Z fperez $
+$Id: iplib.py 976 2005-12-30 01:02:09Z fperez $
 """
 
 #*****************************************************************************
@@ -1744,7 +1744,21 b' want to merge them back into the new files.""" % locals()'
             return self.handle_normal(line,continue_prompt)
 
         if oinfo is None:
-            oinfo = self._ofind(iFun) # FIXME - _ofind is part of Magic
+            # let's try to ensure that _oinfo is ONLY called when autocall is
+            # on.  Since it has inevitable potential side effects, at least
+            # having autocall off should be a guarantee to the user that no
+            # weird things will happen.
+
+            if self.rc.autocall:
+                oinfo = self._ofind(iFun) # FIXME - _ofind is part of Magic
+            else:
+                # in this case, all that's left is either an alias or
+                # processing the line normally.
+                if iFun in self.alias_table:
+                    return self.handle_alias(line,continue_prompt,
+                                             pre,iFun,theRest)
+                else:
+                    return self.handle_normal(line,continue_prompt)
         
         if not oinfo['found']:
             return self.handle_normal(line,continue_prompt)

doc/ChangeLog

@@ -3,6 +3,12 b''
 	* IPython/iplib.py (showtraceback): remove use of the
 	sys.last_{type/value/traceback} structures, which are non
 	thread-safe.
+	(_prefilter): change control flow to ensure that we NEVER
+	introspect objects when autocall is off.  This will guarantee that
+	having an input line of the form 'x.y', where access to attribute
+	'y' has side effects, doesn't trigger the side effect TWICE.  It
+	is important to note that, with autocall on, these side effects
+	can still happen.
 
 	* IPython/macro.py (Macro.__init__): moved macros to a standalone
 	file.  Now that they'll be more likely to be used with the