Re: [RFC/PATCH 2/6] transport_get(): Don't SEGFAULT on missing url

Johan Herland [off-list ref] writes:

Signed-off-by: Johan Herland <redacted>

How does url end up to be NULL?  At the beginning of transport_get(), you
do this:

	ret->remote = remote;
	if (!url && remote && remote->url)
		url = remote->url[0];
	ret->url = url;
	if (remote && remote->foreign_vcs) {
		transport_helper_init(ret);
		return ret;
	}

and the case where remote.$name.vcs is defined, we do not need
remote.$name.url.

When (!url && remote && remote->url), is remote->url[0] allowed to be
NULL?  I am guessing it would be a bug in whoever prepared the remote, and
if that is indeed the case, the patch shifts the symptoms without fixing
the cause.

When (remote && remote->foreign_vcs) does not hold, iow, if no remote is
defined or the remote is defined but lacks remote.$name.url, you will go
to the last else clause in the function that sets up a git_transport_data
for the native transport, but it has ret->url == NULL.  

Whom does that transport talk with?  Is such a transport of any use, or
does it cause a segfault downstream in the call chain?

In other words, I am wondering if this patch should just diagnose the case
as an error, instead of pretending all is well.