From: nisse@lysator.liu.se.?= (Niels =?UTF-8?Q?M=C3=B6ller)
To: bug-gnu-emacs@gnu.org
Subject: bug#5046: Too silent error reporting in imap.el:imap-open-1
Date: Thu, 26 Nov 2009 12:34:02 +0100 [thread overview]
Message-ID: <nniqcxcyfp.fsf@stalhein.lysator.liu.se> (raw)
This is a problem that I experienced on emacs-22.3 on w*ndows, but the
code in question seem to be identical in emacs-23.
I tried to configure an nnimap server in Gnus, and connection failed,
with a message
imap: Connecting to the-mail-server.com...failed
with no further details. The real error was hidden by the
condition-case
(setq imap-current-mailbox nil
imap-current-message nil
imap-state 'initial
imap-process (condition-case ()
(funcall (nth 2 (assq imap-stream
imap-stream-alist))
"imap" buffer imap-server imap-port)
((error quit) nil)))
in imap.el:imap-open-1.
After some debugging, involving adding some additional message calls
in imap-open-1, I figured out the trivial source for the problem. A
typo in my .gnus file, where I wrote
nnimap-stream 'tls
rather than
nnimap-stream tls
Now, (quote tls) is not present on the imap-stream alist, which
results in an attempt to funcall nil.
If I had received an error message like "(quote tls) is not a valid
imap stream type", I would have solved the problem a lot quicker.
I'd like to suggest that error reporting is improved as follows:
1. Messages of the form "Connecting to <some host>... failed." should
be used only when the actual problem is related to the network
connection (dns errors, connection refused, possibly tls-related
handshaking errors, etc). It's long time since I read the elisp
documentation, so I'm not sure if there are some defined error
symbols that make this case easy to distinguish from other errors.
And in the case that the error is in fact network related, it would
be helpful to have the message provide any details that are
available, to aid investigation of the underlying networking
problem.
2. When imap-stream is not found on the imap-stream-alist, this should
either be reported in some human-friendly form, or it should raise
an error which is not masked by condition case on the way up. This
would typically indicate either a configuration error (like in my
case), or a bug in whatever code using imap-open. If I had seen the
void-function error for this particular funcall, that would also
have pointed out the problem fairly accurately.
3. The data for the error should not be throuwn away. If nothing more
sensibly can be done to it, even a crude change to
imap-process (condition-case (e)
(funcall (nth 2 (assq imap-stream
imap-stream-alist))
"imap" buffer imap-server imap-port)
((quit) nil)
((error) (message "imap-open: unexpected error %s" e) nil)))
would be an improvement.
Regards,
/Niels
next reply other threads:[~2009-11-26 11:34 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-26 11:34 Niels =?UTF-8?Q?M=C3=B6ller [this message]
2011-09-18 9:27 ` bug#5046: Too silent error reporting in imap.el:imap-open-1 Lars Magne Ingebrigtsen
[not found] <mailman.11620.1259306412.2239.bug-gnu-emacs@gnu.org>
2011-02-11 20:32 ` Ted Zlatanov
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