lib/zodb: Drop client-only parameters from normalized NEO URI

We need to drop client-specific options so that NEO URI that only differ
due to client options while actually pointing to the same NEO server
are equal after normalization.

--------
kirr: See nexedi/neoppod!18 for
the discussion on this subject.

/reviewed-by @kirr
/reviewed-on nexedi/wendelin.core!28

lib/tests/test_zodb.py

@@ -563,6 +563,8 @@ def test_zstor_2zurl(tmpdir, neo_ssl_dict):
         #   any order of options should result in the same normalized URI
         ("neo://cluster@xyz:1?a=1&c=10&b=2", "neo://cluster@xyz:1?a=1&b=2&c=10"),
         ("neo://cluster@xyz:1?b=2&a=1&c=10", "neo://cluster@xyz:1?a=1&b=2&c=10"),
+        #   client options
+        ("neo://cluster@xyz:1?compress=1&read-only=true&logfile=abc.log&cache-size=1024", "neo://cluster@xyz:1"),
     ],
 )
 def test_zurl_normalize_main(zurl, zurl_norm_ok):

lib/zodb.py

@@ -494,6 +494,11 @@ def _znormalize_neo(scheme, netloc, path, query, frag):
             # ca/cert/key is different than a URL with 'neos' scheme,
             # although both point to the same database.
             scheme = "neos"
+    # Drop client specific options.
+    # These options only affect the behaviour of the NEO client, but don't specify
+    # a different NEO server, and therefore need to be dropped.
+    for k in ("compress", "read-only", "logfile", "cache-size"):
+        q.pop(k, 0)
     # Explicitly sort query before reassembling into string to insure
     # parameter order of input URI doesn't impact normalized URI.
     query = urlparse.urlencode(tuple((k, q[k]) for k in sorted(q.keys())), doseq=True)