Use inputhook_wx2 on osx

Fixes  #2762

IPython/lib/inputhookwx.py

@@ -17,6 +17,7 b' Authors: Robin Dunn, Brian Granger, Ondrej Certik'
 # Imports
 #-----------------------------------------------------------------------------
 
+import sys
 import signal
 import time
 from timeit import default_timer as clock
@@ -159,5 +160,11 b' def inputhook_wx3():'
         pass
     return 0
 
-# This is our default implementation
-inputhook_wx = inputhook_wx3
+if sys.platform == 'darwin':
+    # On OSX, evtloop.Pending() always returns True, regardless of there being
+    # any events pending. As such we can't use implementations 1 or 3 of the
+    # inputhook as those depend on a pending/dispatch loop.
+    inputhook_wx = inputhook_wx2
+else:
+    # This is our default implementation
+    inputhook_wx = inputhook_wx3