url: raise error if CONNECT request to proxy was unsuccessful

The deleted code didn’t work on Python 3. On Python 2 (or Python 3 after
adapting it), the function returned in the error case. The subsequent creation
of SSL socket fails during handshake with a nonsense error.

Instead, the user should get an error of what went wrong.

I don’t see how the deleted code would be useful in the error case. The new
code is also closer of what the standard library is doing nowadays that it has
proxy support (which we don’t use in the moment).

In the test, I use port 0 because all the HGPORTs were already taken. In
practice, there should not be any server listening on port 0.

mercurial/url.py

@@ -14,7 +14,6 b' import socket'
 import sys
 
 from .i18n import _
-from .pycompat import getattr
 from . import (
     encoding,
     error,
@@ -200,15 +199,6 b' class httpconnection(keepalive.HTTPConne'
     # must be able to send big bundle as stream.
     send = _gen_sendfile(keepalive.HTTPConnection.send)
 
-    def getresponse(self):
-        proxyres = getattr(self, 'proxyres', None)
-        if proxyres:
-            if proxyres.will_close:
-                self.close()
-            self.proxyres = None
-            return proxyres
-        return keepalive.HTTPConnection.getresponse(self)
-
 
 # Large parts of this function have their origin from before Python 2.6
 # and could potentially be removed.
@@ -261,77 +251,15 b' def _generic_proxytunnel(self):'
             break
         # skip lines that are all whitespace
         list(iter(lambda: res.fp.readline().strip(), b''))
-    res.status = status
-    res.reason = reason.strip()
 
-    if res.status == 200:
+    if status == 200:
         # skip lines until we find a blank line
         list(iter(res.fp.readline, b'\r\n'))
-        return True
-
-    if version == b'HTTP/1.0':
-        res.version = 10
-    elif version.startswith(b'HTTP/1.'):
-        res.version = 11
-    elif version == b'HTTP/0.9':
-        res.version = 9
     else:
-        raise httplib.UnknownProtocol(version)
-
-    if res.version == 9:
-        res.length = None
-        res.chunked = 0
-        res.will_close = 1
-        res.msg = httplib.HTTPMessage(stringio())
-        return False
-
-    res.msg = httplib.HTTPMessage(res.fp)
-    res.msg.fp = None
-
-    # are we using the chunked-style of transfer encoding?
-    trenc = res.msg.getheader(b'transfer-encoding')
-    if trenc and trenc.lower() == b"chunked":
-        res.chunked = 1
-        res.chunk_left = None
-    else:
-        res.chunked = 0
-
-    # will the connection close at the end of the response?
-    res.will_close = res._check_close()
-
-    # do we have a Content-Length?
-    # NOTE: RFC 2616, section 4.4, #3 says we ignore this if
-    # transfer-encoding is "chunked"
-    length = res.msg.getheader(b'content-length')
-    if length and not res.chunked:
-        try:
-            res.length = int(length)
-        except ValueError:
-            res.length = None
-        else:
-            if res.length < 0:  # ignore nonsensical negative lengths
-                res.length = None
-    else:
-        res.length = None
-
-    # does the body have a fixed length? (of zero)
-    if (
-        status == httplib.NO_CONTENT
-        or status == httplib.NOT_MODIFIED
-        or 100 <= status < 200
-        or res._method == b'HEAD'  # 1xx codes
-    ):
-        res.length = 0
-
-    # if the connection remains open, and we aren't using chunked, and
-    # a content-length was not provided, then assume that the connection
-    # WILL close.
-    if not res.will_close and not res.chunked and res.length is None:
-        res.will_close = 1
-
-    self.proxyres = res
-
-    return False
+        self.close()
+        raise socket.error(
+            "Tunnel connection failed: %d %s" % (status, reason.strip())
+        )
 
 
 class httphandler(keepalive.HTTPHandler):

tests/test-https.t

@@ -490,6 +490,13 b' Test https with cert problems through pr'
   abort: error: *certificate verify failed* (glob)
   [100]
 
+Test when proxy can't connect to server
+
+  $ http_proxy=http://localhost:$HGPORT1/ hg -R copy-pull pull --insecure https://localhost:0/
+  pulling from https://localhost:0/
+  abort: error: Tunnel connection failed: 404 Connection refused
+  [100]
+
 
   $ killdaemons.py hg0.pid