Restore code to remember redirects now we are using urllib2

At times, we can make many separate requests. If we start off with
a URL that bugzilla always redirects (say a HTTP URL), it's better to
"get the message" and start using the target of the redirects.

The code that used to do this was removed with the switch to urllib2.
Add back equivalent code - it can be simplified at this point because
bugzilla was changed to use 301 permanent redirects for HTTP => HTTPS
redirects, and left using 302 requests for attachment
redirects.

https://bugzilla.gnome.org/show_bug.cgi?id=725730

1 files changed, 33 insertions, 1 deletions

diff --git a/git-bz b/git-bz
index 1a9ffbf..8db7caa 100755
--- a/git-bz
+++ b/git-bz
@@ -905,6 +905,37 @@ class BugPatch(object):
 class NoXmlRpcError(Exception):
     pass
 
+class PermanentRedirector(urllib2.HTTPRedirectHandler):
+    def __init__(self, server):
+        self.server = server
+        self.current = None
+
+    def http_error_301(self, req, fp, code, msg, hdrs):
+        if self.current is not None:
+            return urllib2.HTTPRedirectHandler.http_error_301(self, req, fp, code, msg, hdrs)
+
+        # This is a bit of a hack to avoid keeping on redirecting for every
+        # request. If the server redirected the hostname with a permanent redirect,
+        # keeping the path the same, we're assume it's saying "hey, the bugzilla
+        # instance is really over here" - we don't require separate proof for every
+        # different URL.
+
+        # Protect against multiple redirects, which would confuse the logic
+        self.current = req
+        result = urllib2.HTTPRedirectHandler.http_error_301(self, req, fp, code, msg, hdrs)
+
+        old_split = urlparse.urlsplit(req.get_full_url())
+        new_split = urlparse.urlsplit(result.url)
+        new_https = new_split.scheme == 'https'
+
+        if new_split.hostname != self.server.host or new_https != self.server.https:
+            if req.get_method() == 'GET' and old_split.path == new_split.path:
+                self.server.host = new_split.hostname
+                self.server.https = new_https
+
+        self.current = None
+        return result
+
 class BugServer(object):
     def __init__(self, host, path, https, auth_user=None, auth_password=None):
         self.host = host
@@ -912,6 +943,7 @@ class BugServer(object):
         self.https = https
         self.auth_user = auth_user
         self.auth_password = auth_password
+        self.opener = urllib2.build_opener(PermanentRedirector(self))
 
         self.cookies = get_bugzilla_cookies(host)
 
@@ -938,7 +970,7 @@ class BugServer(object):
 
         response = None
         try:
-            response = urllib2.urlopen(req)
+            response = self.opener.open(req)
         except urllib2.HTTPError as err:
             raise err;
         except urllib2.URLError as err: