http: reuse authentication info after the first failed request (issue3567)

[This was applied in 181108726ea5 but backed out again in af02783dea65 because
of Python 2.4 issues. This edition and test-http.t works with Python 2.4.]

Context: mercurial access to repository server with http access, and this
server is protected by basic auth.

Before patch:

* mercurial try an anonymous access to server, server return 401 response and
  mercurial resend request with login / password information

After patch:

* mercurial try an anonymous access to server, server return
  401 response. For all next requests, mercurial keep in memory this
  information (this server need basic auth information).

This patch reduce the number of http access against mercurial server.

Example, before patch:

10.10.168.170 - - [25/Oct/2013:15:44:51 +0200] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:44:52 +0200] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 200 147 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:00 +0200] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:01 +0200] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 200 147 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:03 +0200] "GET /hg/testagt?cmd=batch
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:04 +0200] "GET /hg/testagt?cmd=batch
HTTP/1.1" 200 42 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:06 +0200] "GET /hg/testagt?cmd=getbundle
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:07 +0200] "GET /hg/testagt?cmd=getbundle
HTTP/1.1" 200 61184 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:09 +0200] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:10 +0200] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 200 15 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:12 +0200] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [25/Oct/2013:15:45:12 +0200] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 200 - "-" "mercurial/proto-1.0"

Example after patch:

10.10.168.170 - - [28/Oct/2013:11:49:14 +0100] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 401 260 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:15 +0100] "GET /hg/testagt?cmd=capabilities
HTTP/1.1" 200 147 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:17 +0100] "GET /hg/testagt?cmd=batch
HTTP/1.1" 200 42 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:19 +0100] "GET /hg/testagt?cmd=getbundle
HTTP/1.1" 200 61184 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:22 +0100] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 200 15 "-" "mercurial/proto-1.0"
10.10.168.170 - - [28/Oct/2013:11:49:24 +0100] "GET /hg/testagt?cmd=listkeys
HTTP/1.1" 200 - "-" "mercurial/proto-1.0"

In this last example, you can see only one 401 response.

mercurial/url.py

@@ -7,7 +7,7 b''
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
-import urllib, urllib2, httplib, os, socket, cStringIO
+import urllib, urllib2, httplib, os, socket, cStringIO, base64
 from i18n import _
 import keepalive, util, sslutil
 import httpconnection as httpconnectionmod
@@ -422,9 +422,22 b' class httpdigestauthhandler(urllib2.HTTP'
 
 class httpbasicauthhandler(urllib2.HTTPBasicAuthHandler):
     def __init__(self, *args, **kwargs):
+        self.auth = None
         urllib2.HTTPBasicAuthHandler.__init__(self, *args, **kwargs)
         self.retried_req = None
 
+    def http_request(self, request):
+        if self.auth:
+            request.add_unredirected_header(self.auth_header, self.auth)
+
+        return request
+
+    def https_request(self, request):
+        if self.auth:
+            request.add_unredirected_header(self.auth_header, self.auth)
+
+        return request
+
     def reset_retry_count(self):
         # Python 2.6.5 will call this on 401 or 407 errors and thus loop
         # forever. We disable reset_retry_count completely and reset in
@@ -439,6 +452,19 b' class httpbasicauthhandler(urllib2.HTTPB'
         return urllib2.HTTPBasicAuthHandler.http_error_auth_reqed(
                         self, auth_header, host, req, headers)
 
+    def retry_http_basic_auth(self, host, req, realm):
+        user, pw = self.passwd.find_user_password(realm, req.get_full_url())
+        if pw is not None:
+            raw = "%s:%s" % (user, pw)
+            auth = 'Basic %s' % base64.b64encode(raw).strip()
+            if req.headers.get(self.auth_header, None) == auth:
+                return None
+            self.auth = auth
+            req.add_unredirected_header(self.auth_header, auth)
+            return self.parent.open(req)
+        else:
+            return None
+
 handlerfuncs = []
 
 def opener(ui, authinfo=None):

tests/test-http.t

@@ -226,37 +226,31 b' test http authentication'
   "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip
   "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=namespaces
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces
-  "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=capabilities HTTP/1.1" 200 -
   "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip
   "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=namespaces
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces
-  "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=capabilities HTTP/1.1" 200 -
   "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip
   "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=namespaces
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces
-  "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=capabilities HTTP/1.1" 200 -
   "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip
   "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=namespaces
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces
-  "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=capabilities HTTP/1.1" 200 -
   "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip
   "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=namespaces
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=namespaces
-  "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=capabilities HTTP/1.1" 200 -
   "GET /?cmd=branchmap HTTP/1.1" 200 -
   "GET /?cmd=stream_out HTTP/1.1" 401 -
   "GET /?cmd=stream_out HTTP/1.1" 200 -
-  "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=capabilities HTTP/1.1" 200 -
   "GET /?cmd=lookup HTTP/1.1" 200 - x-hgarg-1:key=tip
@@ -271,13 +265,9 b' test http authentication'
   "GET /?cmd=branchmap HTTP/1.1" 200 -
   "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks
-  "POST /?cmd=unbundle HTTP/1.1" 401 - x-hgarg-1:heads=686173686564+5eb5abfefeea63c80dd7553bcc3783f37e0c5524
   "POST /?cmd=unbundle HTTP/1.1" 200 - x-hgarg-1:heads=686173686564+5eb5abfefeea63c80dd7553bcc3783f37e0c5524
-  "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=phases
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=phases
-  "POST /?cmd=pushkey HTTP/1.1" 401 - x-hgarg-1:key=7f4e523d01f2cc3765ac8934da3d14db775ff872&namespace=phases&new=0&old=1
   "POST /?cmd=pushkey HTTP/1.1" 200 - x-hgarg-1:key=7f4e523d01f2cc3765ac8934da3d14db775ff872&namespace=phases&new=0&old=1
-  "GET /?cmd=listkeys HTTP/1.1" 401 - x-hgarg-1:namespace=bookmarks
   "GET /?cmd=listkeys HTTP/1.1" 200 - x-hgarg-1:namespace=bookmarks
 
 #endif