[PATCH] util: remove the copypasta unquote function

[Martijn Pieters]

# HG changeset patch
# User Martijn Pieters <mjpieters at fb.com>
# Date 1475852815 -7200
#      Fri Oct 07 17:06:55 2016 +0200
# Node ID 6d09435aa2e217f6514da8b3d6ae5b78934a19ed
# Parent  91a3c58ecf938ed675f5364b88f0d663f12b0047
util: remove the copypasta unquote function

The _urlunquote function was added back in the day to improve startup
performance, but this version is a) not compatible with Python 3 and b) has
quadratic performance issues that Python core solved eons ago.

Moreover, the function moved from urllib to urlparse (cheaper to import) *and*
that module is already imported into pycompat. As a result, removing this
function improves perf now.

Before:

! wall 0.066773 comb 0.000000 user 0.000000 sys 0.000000 (best of 100)

After:

! wall 0.065990 comb 0.000000 user 0.000000 sys 0.000000 (best of 100)

diff --git a/mercurial/util.py b/mercurial/util.py
--- a/mercurial/util.py
+++ b/mercurial/util.py
@@ -2297,30 +2297,6 @@
     """
     return _booleans.get(s.lower(), None)
 
-_hexdig = '0123456789ABCDEFabcdef'
-_hextochr = dict((a + b, chr(int(a + b, 16)))
-                 for a in _hexdig for b in _hexdig)
-
-def _urlunquote(s):
-    """Decode HTTP/HTML % encoding.
-
-    >>> _urlunquote('abc%20def')
-    'abc def'
-    """
-    res = s.split('%')
-    # fastpath
-    if len(res) == 1:
-        return s
-    s = res[0]
-    for item in res[1:]:
-        try:
-            s += _hextochr[item[:2]] + item[2:]
-        except KeyError:
-            s += '%' + item
-        except UnicodeDecodeError:
-            s += unichr(int(item[:2], 16)) + item[2:]
-    return s
-
 class url(object):
     r"""Reliable URL parser.
 
@@ -2489,7 +2465,7 @@
                   'path', 'fragment'):
             v = getattr(self, a)
             if v is not None:
-                setattr(self, a, _urlunquote(v))
+                setattr(self, a, pycompat.urlparse.unquote(v))
 
     def __repr__(self):
         attrs = []