test-pathencode: compare current pathencoding implementations

We already have two implementations of the pathencoding (C and
Python) and this test can perfectly well be used to probabilistically
test them instead of just wasting CPU cycles and test time.

tests/test-pathencode.py

@@ -13,9 +13,6 b' import collections'
 if sys.version_info[:2] < (2, 6):
     sys.exit(0)
 
-def hybridencode(path):
-    return store._hybridencode(path, True)
-
 validchars = set(map(chr, range(0, 256)))
 alphanum = range(ord('A'), ord('Z'))
 
@@ -157,7 +154,15 b' def genpath(rng, count):'
 def runtests(rng, seed, count):
     nerrs = 0
     for p in genpath(rng, count):
-        hybridencode(p)
+        h = store._dothybridencode(p)    # uses C implementation, if available
+        r = store._hybridencode(p, True) # reference implementation in Python
+        if h != r:
+            if nerrs == 0:
+                print >> sys.stderr, 'seed:', hex(seed)[:-1]
+            print >> sys.stderr, "\np: '%s'" % p.encode("string_escape")
+            print >> sys.stderr, "h: '%s'" % h.encode("string_escape")
+            print >> sys.stderr, "r: '%s'" % r.encode("string_escape")
+            nerrs += 1
     return nerrs
 
 def main():