oinfo finds cell magics with same name as line magics

closes  #1904

IPython/core/interactiveshell.py

@@ -61,7 +61,7 b' from IPython.core.logger import Logger'
 from IPython.core.macro import Macro
 from IPython.core.payload import PayloadManager
 from IPython.core.plugin import PluginManager
-from IPython.core.prefilter import PrefilterManager, ESC_MAGIC
+from IPython.core.prefilter import PrefilterManager, ESC_MAGIC, ESC_CELL_MAGIC
 from IPython.core.profiledir import ProfileDir
 from IPython.core.pylabtools import pylab_activate
 from IPython.core.prompts import PromptManager
@@ -1348,7 +1348,9 b' class InteractiveShell(SingletonConfigurable):'
         """
         oname = oname.strip()
         #print '1- oname: <%r>' % oname  # dbg
-        if not py3compat.isidentifier(oname.lstrip(ESC_MAGIC), dotted=True):
+        if not oname.startswith(ESC_MAGIC) and \
+            not oname.startswith(ESC_CELL_MAGIC) and \
+            not py3compat.isidentifier(oname, dotted=True):
             return dict(found=False)
 
         alias_ns = None
@@ -1406,11 +1408,18 b' class InteractiveShell(SingletonConfigurable):'
 
         # Try to see if it's magic
         if not found:
-            if oname.startswith(ESC_MAGIC):
-                oname = oname.lstrip(ESC_MAGIC)
-            obj = self.find_line_magic(oname)
-            if obj is None:
+            obj = None
+            if oname.startswith(ESC_CELL_MAGIC):
+                oname = oname.lstrip(ESC_CELL_MAGIC)
                 obj = self.find_cell_magic(oname)
+            elif oname.startswith(ESC_MAGIC):
+                oname = oname.lstrip(ESC_MAGIC)
+                obj = self.find_line_magic(oname)
+            else:
+                # search without prefix, so run? will find %run?
+                obj = self.find_line_magic(oname)
+                if obj is None:
+                    obj = self.find_cell_magic(oname)
             if obj is not None:
                 found = True
                 ospace = 'IPython internal'

IPython/core/prefilter.py

@@ -50,6 +50,7 b" ESC_SHELL = '!'"
 ESC_SH_CAP = '!!'
 ESC_HELP   = '?'
 ESC_MAGIC  = '%'
+ESC_CELL_MAGIC = ESC_MAGIC * 2
 ESC_QUOTE  = ','
 ESC_QUOTE2 = ';'
 ESC_PAREN  = '/'