url: allow to configure timeout on http connection

url: allow to configure timeout on http connection

By default, httplib.HTTPConnection opens connection with no timeout.
If the server is hanging, Mercurial will wait indefinitely. This may be an
issue for automated scripts.

Differential Revision: https://phab.mercurial-scm.org/D4878

--- a/mercurial/configitems.py	Wed Sep 26 23:50:14 2018 +0200
+++ b/mercurial/configitems.py	Thu Oct 04 11:28:48 2018 +0200
@@ -737,6 +737,11 @@
 coreconfigitem('http_proxy', 'user',
     default=None,
 )
+
+coreconfigitem('http', 'timeout',
+    default=None,
+)
+
 coreconfigitem('logtoprocess', 'commandexception',
     default=None,
 )

--- a/mercurial/help/config.txt	Wed Sep 26 23:50:14 2018 +0200
+++ b/mercurial/help/config.txt	Thu Oct 04 11:28:48 2018 +0200
@@ -1322,6 +1322,15 @@
     Optional. Always use the proxy, even for localhost and any entries
     in ``http_proxy.no``. (default: False)
 
+``http``
+----------
+
+Used to configure access to Mercurial repositories via HTTP.
+
+``timeout``
+    If set, blocking operations will timeout after that many seconds.
+    (default: None)
+
 ``merge``
 ---------
 

--- a/mercurial/keepalive.py	Wed Sep 26 23:50:14 2018 +0200
+++ b/mercurial/keepalive.py	Thu Oct 04 11:28:48 2018 +0200
@@ -172,8 +172,9 @@
             return dict(self._hostmap)
 
 class KeepAliveHandler(object):
-    def __init__(self):
+    def __init__(self, timeout=None):
         self._cm = ConnectionManager()
+        self._timeout = timeout
         self.requestscount = 0
         self.sentbytescount = 0
 
@@ -234,7 +235,7 @@
                 h = self._cm.get_ready_conn(host)
             else:
                 # no (working) free connections were found.  Create a new one.
-                h = http_class(host)
+                h = http_class(host, timeout=self._timeout)
                 if DEBUG:
                     DEBUG.info("creating new connection to %s (%d)",
                                host, id(h))

--- a/mercurial/url.py	Wed Sep 26 23:50:14 2018 +0200
+++ b/mercurial/url.py	Thu Oct 04 11:28:48 2018 +0200
@@ -317,8 +317,8 @@
 
 class logginghttphandler(httphandler):
     """HTTP handler that logs socket I/O."""
-    def __init__(self, logfh, name, observeropts):
-        super(logginghttphandler, self).__init__()
+    def __init__(self, logfh, name, observeropts, timeout=None):
+        super(logginghttphandler, self).__init__(timeout=timeout)
 
         self._logfh = logfh
         self._logname = name
@@ -365,8 +365,8 @@
             sslutil.validatesocket(self.sock)
 
     class httpshandler(keepalive.KeepAliveHandler, urlreq.httpshandler):
-        def __init__(self, ui):
-            keepalive.KeepAliveHandler.__init__(self)
+        def __init__(self, ui, timeout=None):
+            keepalive.KeepAliveHandler.__init__(self, timeout=timeout)
             urlreq.httpshandler.__init__(self)
             self.ui = ui
             self.pwmgr = passwordmgr(self.ui,
@@ -525,18 +525,19 @@
     ``sendaccept`` allows controlling whether the ``Accept`` request header
     is sent. The header is sent by default.
     '''
+    timeout = ui.configwith(float, 'http', 'timeout')
     handlers = []
 
     if loggingfh:
         handlers.append(logginghttphandler(loggingfh, loggingname,
-                                           loggingopts or {}))
+                                           loggingopts or {}, timeout=timeout))
         # We don't yet support HTTPS when logging I/O. If we attempt to open
         # an HTTPS URL, we'll likely fail due to unknown protocol.
 
     else:
-        handlers.append(httphandler())
+        handlers.append(httphandler(timeout=timeout))
         if has_https:
-            handlers.append(httpshandler(ui))
+            handlers.append(httpshandler(ui, timeout=timeout))
 
     handlers.append(proxyhandler(ui))