Older cURL wanted piece of memory we call it with to be stable, but
we updated the auth material after handing it to a call.

* bc/http-keep-memory-given-to-curl:
  http.c: don't rewrite the user:passwd string multiple times

Curl older than 7.17 (RHEL 4.X provides 7.12 and RHEL 5.X provides
7.15) requires that we manage any strings that we pass to it as
pointers.  So, we really shouldn't be modifying this strbuf after we
have passed it to curl.

Our interaction with curl is currently safe (before or after this
patch) since the pointer that is passed to curl is never invalidated;
it is repeatedly rewritten with the same sequence of characters but
the strbuf functions never need to allocate a larger string, so the
same memory buffer is reused.

This "guarantee" of safety is somewhat subtle and could be overlooked
by someone who may want to add a more complex handling of the username
and password.  So, let's stop modifying this strbuf after we have
passed it to curl, but also leave a note to describe the assumptions
that have been made about username/password lifetime and to draw
attention to the code.

Signed-off-by: Brandon Casey <drafnel@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Does anybody really use commit walkers over (s)ftp?

* mv/ssl-ftp-curl:
  Support FTP-over-SSL/TLS for regular FTP

Because we reuse curl handles for multiple requests, the
setup of a handle happens in two stages: stable, global
setup and per-request setup. The lifecycle of a handle is
something like:

  1. get_curl_handle; do basic global setup that will last
     through the whole program (e.g., setting the user
     agent, ssl options, etc)

  2. get_active_slot; set up a per-request baseline (e.g.,
     clearing the read/write functions, making it a GET
     request, etc)

  3. perform the request with curl_*_perform functions

  4. goto step 2 to perform another request

Breaking it down this way means we can avoid doing global
setup from step (1) repeatedly, but we still finish step (2)
with a predictable baseline setup that callers can rely on.

Until commit 6d052d7 (http: add HTTP_KEEP_ERROR option,
2013-04-05), setting curl's FAILONERROR option was a global
setup; we never changed it. However, 6d052d7 introduced an
option where some requests might turn off FAILONERROR. Later
requests using the same handle would have the option
unexpectedly turned off, which meant they would not notice
http failures at all.

This could easily be seen in the test-suite for the
"half-auth" cases of t5541 and t5551. The initial requests
turned off FAILONERROR, which meant it was erroneously off
for the rpc POST. That worked fine for a successful request,
but meant that we failed to react properly to the HTTP 401
(instead, we treated whatever the server handed us as a
successful message body).

The solution is simple: now that FAILONERROR is a
per-request setting, we move it to get_active_slot to make
sure it is reset for each request.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Add a boolean http.sslTry option which allows to enable AUTH SSL/TLS and
encrypted data transfers when connecting via regular FTP protocol.

Default is false since it might trigger certificate verification errors on
misconfigured servers.

Signed-off-by: Modestas Vainius <modestas@vainius.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

This function is a single-liner and is only called from one
place. Just inline it, which makes the code more obvious.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

When we report an http error code, we say something like:

  error: The requested URL reported failure: 403 Forbidden while accessing http://example.com/repo.git

Everything between "error:" and "while" is written by curl,
and the resulting sentence is hard to read (especially
because there is no punctuation between curl's sentence and
the remainder of ours). Instead, let's re-order this to give
better flow:

  error: unable to access 'http://example.com/repo.git: The requested URL reported failure: 403 Forbidden

This is still annoyingly long, but at least reads more
clearly left to right.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

This helper function should really be a one-liner that
prints an error message, but it has ended up unnecessarily
complicated:

  1. We call error() directly when we fail to start the curl
     request, so we must later avoid printing a duplicate
     error in http_error().

     It would be much simpler in this case to just stuff the
     error message into our usual curl_errorstr buffer
     rather than printing it ourselves. This means that
     http_error does not even have to care about curl's exit
     value (the interesting part is in the errorstr buffer
     already).

  2. We return the "ret" value passed in to us, but none of
     the callers actually cares about our return value. We
     can just drop this entirely.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

We currently set curl's FAILONERROR option, which means that
any http failures are reported as curl errors, and the
http body content from the server is thrown away.

This patch introduces a new option to http_get_strbuf which
specifies that the body content from a failed http response
should be placed in the destination strbuf, where it can be
accessed by the caller.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Having the packet sizes defined near the packet read/write
functions makes more sense.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>