short error message on AliasError in run_cell

instead of full traceback

use prefilter_failed flag to prevent duplicate code

IPython/core/interactiveshell.py

@@ -38,7 +38,7 b' from IPython.core import page'
 from IPython.core import prefilter
 from IPython.core import shadowns
 from IPython.core import ultratb
-from IPython.core.alias import AliasManager
+from IPython.core.alias import AliasManager, AliasError
 from IPython.core.autocall import ExitAutocall
 from IPython.core.builtin_trap import BuiltinTrap
 from IPython.core.compilerop import CachingCompiler
@@ -2129,21 +2129,17 b' class InteractiveShell(Configurable, Magic):'
         cell = self.input_splitter.source_reset()
         
         with self.builtin_trap:
+            prefilter_failed = False
             if len(cell.splitlines()) == 1:
                 try:
                     cell = self.prefilter_manager.prefilter_lines(cell)
+                except AliasError as e:
+                    error(e)
+                    prefilter_failed=True
                 except Exception:
-                    # don't allow prefilter errors to crash IPython, because
-                    # user code can be involved (e.g. aliases)
+                    # don't allow prefilter errors to crash IPython
                     self.showtraceback()
-                    if store_history:
-                        self.history_manager.store_inputs(self.execution_count, 
-                                                          cell, raw_cell)
-
-                    self.logger.log(cell, raw_cell)
-                    self.execution_count += 1
-                    
-                    return
+                    prefilter_failed = True
             
             # Store raw and processed history
             if store_history:
@@ -2152,6 +2148,8 b' class InteractiveShell(Configurable, Magic):'
 
             self.logger.log(cell, raw_cell)
             
+            if not prefilter_failed:
+                # don't run if prefilter failed
             cell_name = self.compile.cache(cell, self.execution_count)
             
             with self.display_trap:

IPython/core/tests/test_interactiveshell.py

@@ -20,7 +20,10 b' Authors'
 #-----------------------------------------------------------------------------
 # stdlib
 import unittest
+from cStringIO import StringIO
+
 from IPython.testing import decorators as dec
+from IPython.utils import io
 
 #-----------------------------------------------------------------------------
 # Tests
@@ -96,4 +99,11 b' class InteractiveShellTestCase(unittest.TestCase):'
         """Errors in prefilter can't crash IPython"""
         ip = get_ipython()
         ip.run_cell('%alias parts echo first %s second %s')
+        # capture stderr:
+        save_err = io.stderr
+        io.stderr = StringIO()
         ip.run_cell('parts 1')
+        err = io.stderr.getvalue()
+        io.stderr = save_err
+        self.assertEquals(err.split(':')[0], 'ERROR')
+