Fix unescape_glob: support escaping "\"

IPython/utils/path.py

@@ -358,9 +358,11 b' def expand_path(s):'
 
 def unescape_glob(string):
     """Unescape glob pattern in `string`."""
-    for pattern in '*[]!?':
-        string = string.replace(r'\{0}'.format(pattern), pattern)
-    return string
+    def unescape(s):
+        for pattern in '*[]!?':
+            s = s.replace(r'\{0}'.format(pattern), pattern)
+        return s
+    return '\\'.join(map(unescape, string.split('\\\\')))
 
 
 def shellglob(args):

IPython/utils/tests/test_path.py

@@ -486,3 +486,7 b' def test_shellglob():'
 
 def test_unescape_glob():
     nt.assert_equals(path.unescape_glob(r'\*\[\!\]\?'), '*[!]?')
+    nt.assert_equals(path.unescape_glob(r'\\*'), r'\*')
+    nt.assert_equals(path.unescape_glob(r'\\\*'), r'\*')
+    nt.assert_equals(path.unescape_glob(r'\\a'), r'\a')
+    nt.assert_equals(path.unescape_glob(r'\a'), r'\a')