Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.
The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).
This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.
I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many messages will be marked for translation in the following
commits. This commit updates some of them to be more consistent and
reduce diff noise in those commits. Changes are
- keep the first letter of die(), error() and warning() in lowercase
- no full stop in die(), error() or warning() if it's single sentence
messages
- indentation
- some messages are turned to BUG(), or prefixed with "BUG:" and will
not be marked for i18n
- some messages are improved to give more information
- some messages are broken down by sentence to be i18n friendly
(on the same token, combine multiple warning() into one big string)
- the trailing \n is converted to printf_ln if possible, or deleted
if not redundant
- errno_errno() is used instead of explicit strerror()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The list of commands with their various attributes were spread
across a few places in the build procedure, but it now is getting a
bit more consolidated to allow more automation.
* nd/command-list:
completion: allow to customize the completable command list
completion: add and use --list-cmds=alias
completion: add and use --list-cmds=nohelpers
Move declaration for alias.c to alias.h
completion: reduce completable command list
completion: let git provide the completable command list
command-list.txt: documentation and guide line
help: use command-list.txt for the source of guides
help: add "-a --verbose" to list all commands with synopsis
git: support --list-cmds=list-<category>
completion: implement and use --list-cmds=main,others
git --list-cmds: collect command list in a string_list
git.c: convert --list-* to --list-cmds=*
Remove common-cmds.h
help: use command-list.h for common command list
generate-cmds.sh: export all commands to command-list.h
generate-cmds.sh: factor out synopsis extract code
The transport protocol v2 is getting updated further.
* bw/server-options:
fetch: send server options when using protocol v2
ls-remote: send server options when using protocol v2
serve: introduce the server-option capability
The build procedure "make DEVELOPER=YesPlease" learned to enable a
bit more warning options depending on the compiler used to help
developers more. There also is "make DEVOPTS=tokens" knob
available now, for those who want to help fixing warnings we
usually ignore, for example.
* nd/warn-more-for-devs:
Makefile: add a DEVOPTS to get all of -Wextra
Makefile: add a DEVOPTS to suppress -Werror under DEVELOPER
Makefile: detect compiler and enable more warnings in DEVELOPER=1
connect.c: mark die_initial_contact() NORETURN
Teach ls-remote to optionally accept server options by specifying them
on the cmdline via '-o' or '--server-option'. These server options are
sent to the remote end when querying for the remote end's refs using
protocol version 2.
If communicating using a protocol other than v2 the provided options are
ignored and not sent to the remote end.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is a series running in parallel with this one that adds code
like this
switch (...) {
case ...:
die_initial_contact();
case ...:
There is nothing wrong with this. There is no actual falling
through. But since gcc is not that smart and gcc 7.x introduces
-Wimplicit-fallthrough, it raises a false alarm in this case.
This class of warnings may be useful elsewhere, so instead of
suppressing the whole class, let's try to fix just this code. gcc is
smart enough to realize that no execution can continue after a
NORETURN function call and no longer raises the warning.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to be able to ship protocol v2 with only supporting fetch, we
need clients to not issue a request to use protocol v2 when pushing
(since the client currently doesn't know how to push using protocol v2).
This allows a client to have protocol v2 configured in
`protocol.version` and take advantage of using v2 for fetch and falling
back to using v0 when pushing while v2 for push is being designed.
We could run into issues if we didn't fall back to protocol v2 when
pushing right now. This is because currently a server will ignore a request to
use v2 when contacting the 'receive-pack' endpoint and fall back to
using v0, but when push v2 is rolled out to servers, the 'receive-pack'
endpoint will start responding using v2. So we don't want to get into a
state where a client is requesting to push with v2 before they actually
know how to push using v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of having each builtin transport asking for which protocol
version the user has configured in 'protocol.version' by calling
`get_protocol_version_config()` multiple times, factor this logic out
so there is just a single call at the beginning of `git_connect()`.
This will be helpful in the next patch where we can have centralized
logic which determines if we need to request a different protocol
version than what the user has configured.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enable shallow clones and deepen requests using protocol version 2 if
the server 'fetch' command supports the 'shallow' feature.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the client to be able to request a remote's refs using protocol
v2. This is done by having a client issue a 'ls-refs' request to a v2
server.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce protocol_v2, a new value for 'enum protocol_version'.
Subsequent patches will fill in the implementation of protocol_v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to prepare for the addition of protocol_v2 push the protocol
version discovery outside of 'get_remote_heads()'. This will allow for
keeping the logic for processing the reference advertisement for
protocol_v1 and protocol_v0 separate from the logic for protocol_v2.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In order to allow for better control flow when protocol_v2 is introduced
convert 'get_remote_heads()' to use 'struct packet_reader' to read
packet lines. This enables a client to be able to peek the first line
of a server's response (without consuming it) in order to determine the
protocol version its speaking and then passing control to the
appropriate handler.
This is needed because the initial response from a server speaking
protocol_v0 includes the first ref, while subsequent protocol versions
respond with a version line. We want to be able to read this first line
without consuming the first ref sent in the protocol_v0 case so that the
protocol version the server is speaking can be determined outside of
'get_remote_heads()' in a future patch.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation/CodingGuidelines explains:
- Multi-line comments include their delimiters on separate lines from
the text. E.g.
/*
* A very long
* multi-line comment.
*/
Reported-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When trying to connect to an ssh:// URL with port explicitly specified
and the ssh command configured with GIT_SSH does not support such a
setting, it is less confusing to error out than to silently suppress
the port setting and continue.
This requires updating the GIT_SSH setting in t5603-clone-dirname.sh.
That test is about the directory name produced when cloning various
URLs. It uses an ssh wrapper that ignores all its arguments but does
not declare that it supports a port argument; update it to set
GIT_SSH_VARIANT=ssh to do so. (Real-life ssh wrappers that pass a
port argument to OpenSSH would also support -G and would not require
such an update.)
Reported-by: William Yan <wyan@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the user passes -4/--ipv4 or -6/--ipv6 to "git fetch" or "git push"
and the ssh command configured with GIT_SSH does not support such a
setting, error out instead of ignoring the option and continuing.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Android's "repo" tool is a tool for managing a large codebase
consisting of multiple smaller repositories, similar to Git's
submodule feature. Starting with Git 94b8ae5a (ssh: introduce a
'simple' ssh variant, 2017-10-16), users noticed that it stopped
handling the port in ssh:// URLs.
The cause: when it encounters ssh:// URLs, repo pre-connects to the
server and sets GIT_SSH to a helper ".repo/repo/git_ssh" that reuses
that connection. Before 94b8ae5a, the helper was assumed to support
OpenSSH options for lack of a better guess and got passed a -p option
to set the port. After that patch, it uses the new default of a
simple helper that does not accept an option to set the port.
The next release of "repo" will set GIT_SSH_VARIANT to "ssh" to avoid
that. But users of old versions and of other similar GIT_SSH
implementations would not get the benefit of that fix.
So update the default to use OpenSSH options again, with a twist. As
observed in 94b8ae5a, we cannot assume that $GIT_SSH always handles
OpenSSH options: common helpers such as travis-ci's dpl[*] are
configured using GIT_SSH and do not accept OpenSSH options. So make
the default a new variant "auto", with the following behavior:
1. First, check for a recognized basename, like today.
2. If the basename is not recognized, check whether $GIT_SSH supports
OpenSSH options by running
$GIT_SSH -G <options> <host>
This returns status 0 and prints configuration in OpenSSH if it
recognizes all <options> and returns status 255 if it encounters
an unrecognized option. A wrapper script like
exec ssh -- "$@"
would fail with
ssh: Could not resolve hostname -g: Name or service not known
, correctly reflecting that it does not support OpenSSH options.
The command is run with stdin, stdout, and stderr redirected to
/dev/null so even a command that expects a terminal would exit
immediately.
3. Based on the result from step (2), behave like "ssh" (if it
succeeded) or "simple" (if it failed).
This way, the default ssh variant for unrecognized commands can handle
both the repo and dpl cases as intended.
This autodetection has been running on Google workstations since
2017-10-23 with no reported negative effects.
[*] 6c3fddfda1/lib/dpl/provider.rb (L215)
Reported-by: William Yan <wyan@google.com>
Improved-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This puts the determination of options to pass to each ssh variant
(see ssh.variant in git-config(1)) in one place.
A follow-up patch will use this in an initial dry run to detect which
variant to use when the ssh command is ambiguous.
No functional change intended yet.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git_connect function is growing long. Split the portion that
discovers an ssh command and options it accepts before the service
name and path to a separate function to make it easier to read.
No functional change intended.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git_connect function is growing long. Split the
PROTO_GIT-specific portion to a separate function to make it easier to
read.
No functional change intended.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git_connect has the structure
struct child_process *conn = &no_fork;
...
switch (protocol) {
case PROTO_GIT:
if (git_use_proxy(hostandport))
conn = git_proxy_connect(fd, hostandport);
else
git_tcp_connect(fd, hostandport, flags);
...
break;
case PROTO_SSH:
conn = xmalloc(sizeof(*conn));
child_process_init(conn);
argv_array_push(&conn->args, ssh);
...
break;
...
return conn;
In all cases except the git_tcp_connect case, conn is explicitly
assigned a value. Make the code clearer by explicitly assigning
'conn = &no_fork' in the tcp case and eliminating the default so the
compiler can ensure conn is always correctly assigned.
Noticed-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When using the 'ssh' transport, the '-o' option is used to specify an
environment variable which should be set on the remote end. This allows
git to send additional information when contacting the server,
requesting the use of a different protocol version via the
'GIT_PROTOCOL' environment variable like so: "-o SendEnv=GIT_PROTOCOL".
Unfortunately not all ssh variants support the sending of environment
variables to the remote end. To account for this, only use the '-o'
option for ssh variants which are OpenSSH compliant. This is done by
checking that the basename of the ssh command is 'ssh' or the ssh
variant is overridden to be 'ssh' (via the ssh.variant config).
Other options like '-p' and '-P', which are used to specify a specific
port to use, or '-4' and '-6', which are used to indicate that IPV4 or
IPV6 addresses should be used, may also not be supported by all ssh
variants.
Currently if an ssh command's basename wasn't 'plink' or
'tortoiseplink' git assumes that the command is an OpenSSH variant.
Since user configured ssh commands may not be OpenSSH compliant, tighten
this constraint and assume a variant of 'simple' if the basename of the
command doesn't match the variants known to git. The new ssh variant
'simple' will only have the host and command to execute ([username@]host
command) passed as parameters to the ssh command.
Update the Documentation to better reflect the command-line options sent
to ssh commands based on their variant.
Reported-by: Jeffrey Yasskin <jyasskin@google.com>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach the connection logic to tell a serve that it understands protocol
v1. This is done in 2 different ways for the builtin transports, both
of which ultimately set 'GIT_PROTOCOL' to 'version=1' on the server.
1. git://
A normal request to git-daemon is structured as
"command path/to/repo\0host=..\0" and due to a bug introduced in
49ba83fb6 (Add virtualization support to git-daemon, 2006-09-19) we
aren't able to place any extra arguments (separated by NULs) besides
the host otherwise the parsing of those arguments would enter an
infinite loop. This bug was fixed in 73bb33a94 (daemon: Strictly
parse the "extra arg" part of the command, 2009-06-04) but a check
was put in place to disallow extra arguments so that new clients
wouldn't trigger this bug in older servers.
In order to get around this limitation git-daemon was taught to
recognize additional request arguments hidden behind a second
NUL byte. Requests can then be structured like:
"command path/to/repo\0host=..\0\0version=1\0key=value\0".
git-daemon can then parse out the extra arguments and set
'GIT_PROTOCOL' accordingly.
By placing these extra arguments behind a second NUL byte we can
skirt around both the infinite loop bug in 49ba83fb6 (Add
virtualization support to git-daemon, 2006-09-19) as well as the
explicit disallowing of extra arguments introduced in 73bb33a94
(daemon: Strictly parse the "extra arg" part of the command,
2009-06-04) because both of these versions of git-daemon check for a
single NUL byte after the host argument before terminating the
argument parsing.
2. ssh://, file://
Set 'GIT_PROTOCOL' environment variable with the desired protocol
version. With the file:// transport, 'GIT_PROTOCOL' can be set
explicitly in the locally running git-upload-pack or git-receive-pack
processes. With the ssh:// transport and OpenSSH compliant ssh
programs, 'GIT_PROTOCOL' can be sent across ssh by using '-o
SendEnv=GIT_PROTOCOL' and having the server whitelist this
environment variable.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach a client to recognize that a server understands protocol v1 by
looking at the first pkt-line the server sends in response. This is
done by looking for the response "version 1" send by upload-pack or
receive-pack.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently, get_remote_heads() parses the ref advertisement in one loop,
allowing refs and shallow lines to intersperse, despite this not being
allowed by the specification. Refactor get_remote_heads() to use two
loops instead, enforcing that refs come first, and then shallows.
This also makes it easier to teach get_remote_heads() to interpret other
lines in the ref advertisement, which will be done in a subsequent
patch.
As part of this change, this patch interprets capabilities only on the
first line in the ref advertisement, printing a warning message when
encountering capabilities on other lines.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reduce the scope of the variable cmd and release it before returning
early.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we get a repo path like "-repo.git", we may try to invoke
"git-upload-pack -repo.git". This is going to fail, since
upload-pack will interpret it as a set of bogus options. But
let's reject this before we even run the sub-program, since
we would not want to allow any mischief with repo names that
actually are real command-line options.
You can still ask for such a path via git-daemon, but there's no
security problem there, because git-daemon enters the repo itself
and then passes "." on the command line.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you have a GIT_PROXY_COMMAND configured, we will run it
with the host/port on the command-line. If a URL contains a
mischievous host like "--foo", we don't know how the proxy
command may handle it. It's likely to break, but it may also
do something dangerous and unwanted (technically it could
even do something useful, but that seems unlikely).
We should err on the side of caution and reject this before
we even run the command.
The hostname check matches the one we do in a similar
circumstance for ssh. The port check is not present for ssh,
but there it's not necessary because the syntax is "-p
<port>", and there's no ambiguity on the parsing side.
It's not clear whether you can actually get a negative port
to the proxy here or not. Doing:
git fetch git://remote:-1234/repo.git
keeps the "-1234" as part of the hostname, with the default
port of 9418. But it's a good idea to keep this check close
to the point of running the command to make it clear that
there's no way to circumvent it (and at worst it serves as a
belt-and-suspenders check).
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We reject hostnames that start with a dash because they may
be confused for command-line options. Let's factor out that
notion into a helper function, as we'll use it in more
places. And while it's simple now, it's not clear if some
systems might need more complex logic to handle all cases.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When commands like "git fetch" talk with ssh://$rest_of_URL/, the
code splits $rest_of_URL into components like host, port, etc., and
then spawns the underlying "ssh" program by formulating argv[] array
that has:
- the path to ssh command taken from GIT_SSH_COMMAND, etc.
- dashed options like '-batch' (for Tortoise), '-p <port>' as
needed.
- ssh_host, which is supposed to be the hostname parsed out of
$rest_of_URL.
- then the command to be run on the other side, e.g. git
upload-pack.
If the ssh_host ends up getting '-<anything>', the argv[] that is
used to spawn the command becomes something like:
{ "ssh", "-p", "22", "-<anything>", "command", "to", "run", NULL }
which obviously is bogus, but depending on the actual value of
"<anything>", will make "ssh" parse and use it as an option.
Prevent this by forbidding ssh_host that begins with a "-".
Noticed-by: Joern Schneeweisz of Recurity Labs
Reported-by: Brian at GitLab
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix configuration codepath to pay proper attention to commondir
that is used in multi-worktree situation, and isolate config API
into its own header file.
* bw/config-h:
config: don't implicitly use gitdir or commondir
config: respect commondir
setup: teach discover_git_directory to respect the commondir
config: don't include config.h by default
config: remove git_config_iter
config: create config.h
Stop including config.h by default in cache.h. Instead only include
config.h in those files which require use of the config system.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If we successfully parse a symref value like
"HEAD:refs/heads/master", we add the result to a string
list. But because the string list is marked
STRING_LIST_INIT_DUP, the string list code will make a copy
of the string and add the copy.
This patch fixes it by adding the entry with
string_list_append_nodup(), which lets the string list take
ownership of our newly allocated string. There are two
alternatives that seem like they would work, but aren't the
right solution.
The first is to initialize the list with the "NODUP"
initializer. That would avoid the copy, but then the string
list would not realize that it owns the strings. When we
eventually call string_list_clear(), it would not free the
strings, causing a leak.
The second option would be to use the normal
string_list_append(), but free the local copy in our
function. We can't do this because the local copy actually
contains _two_ strings; the symref name and its target. We
point to the target pointer via the "util" field, and its
memory must last as long as the string list does.
You may also wonder whether it's safe to ever free the local
copy, since the target points into it. The answer is yes,
because we duplicate it in annotaate_refs_with_symref_info
before clearing the string list.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we see an error from split_cmdline(), we exit the
function without freeing the copy of the command string we
made.
This was sort-of introduced by 22e5ae5c8 (connect.c: handle
errors from split_cmdline, 2017-04-10). The leak existed
before that, but before that commit fixed the bug, we could
never trigger this else clause in the first place.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit e9d9a8a4d (connect: handle putty/plink also in
GIT_SSH_COMMAND, 2017-01-02) added a call to
split_cmdline(), but checks only for a non-zero return to
see if we got any output. Since the function returns
negative values (and a NULL argv) on error, we end up
dereferencing NULL and segfaulting.
Arguably we could report on the parsing error here, but it's
probably not worth it. This is a best-effort attempt to see
if we are using plink. So we can simply return here with
"no, it wasn't plink" and let the shell actually complain
about the bogus quoting.
Reported-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since this structure handles an array of object IDs, rename it to struct
oid_array. Also rename the accessor functions and the initialization
constant.
This commit was produced mechanically by providing non-Documentation
files to the following Perl one-liners:
perl -pi -E 's/struct sha1_array/struct oid_array/g'
perl -pi -E 's/\bsha1_array_/oid_array_/g'
perl -pi -E 's/SHA1_ARRAY_INIT/OID_ARRAY_INIT/g'
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the callers to pass struct object_id by changing the function
declaration and definition and applying the following semantic patch:
@@
expression E1, E2;
@@
- sha1_array_append(E1, E2.hash)
+ sha1_array_append(E1, &E2)
@@
expression E1, E2;
@@
- sha1_array_append(E1, E2->hash)
+ sha1_array_append(E1, E2)
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
dd33e07766 ("connect: Add the envvar GIT_SSH_VARIANT and ssh.variant
config", 2017-02-01) attempted to add support for configuration and
environment variable to override the different handling of
port_option and needs_batch settings suitable for variants of the
ssh implementation that was autodetected by looking at the ssh
command name. Because it piggybacked on the code that turns command
name to specific override (e.g. "plink.exe" and "plink" means
port_option needs to be set to 'P' instead of the default 'p'), yet
it defined a separate namespace for these overrides (e.g. "putty"
can be usable to signal that port_option needs to be 'P'), however,
it made the auto-detection based on the command name less robust
(e.g. the code now accepts "putty" as a SSH command name and applies
the same override).
Separate the code that interprets the override that was read from
the configuration & environment from the original code that handles
the command names, as they are in separate namespaces, to fix this
confusion.
This incidentally also makes it easier for future enhancement of the
override syntax (e.g. "port_option=p,needs_batch=1" may want to be
accepted as a more explicit syntax) without affecting the code for
auto-detection based on the command name.
While at it, update the return type of the handle_ssh_variant()
helper function to void; the caller does not use it, and the
function does not return any meaningful value.
Signed-off-by: Junio C Hamano <gitster@pobox.com>