Merge branch 'tq/git-ssh-command'

Allow passing extra set of arguments when ssh is invoked to create
an encrypted & authenticated connection by introducing a new environment
variable GIT_SSH_COMMAND, whose contents is interpreted by shells.

This is not possible with existing GIT_SSH mechanism whose
invocation bypasses shells, which was designed more to match what
other programs with similar variables did, not necessarily to be
more useful.

* tq/git-ssh-command:
git_connect: set ssh shell command in GIT_SSH_COMMAND

diff --combined Documentation/git.txt
index afb48d39bbd229bb0a28d2e7e2fb835e63248525,6a25ba370af7b43fce4a2c61c56d87fbb33e4c35..dd172548f31011d1261c3c09323869596d4d6cb7
--- 1/Documentation/git.txt
--- 2/Documentation/git.txt
+++ b/Documentation/git.txt
@@@ -43,11 -43,6 +43,11 @@@ unreleased) version of Git, that is ava
  branch of the `git.git` repository.
  Documentation for older releases are available here:
  
 +* link:v2.2.0/git.html[documentation for release 2.2]
 +
 +* release notes for
 +  link:RelNotes/2.2.0.txt[2.2].
 +
  * link:v2.1.3/git.html[documentation for release 2.1.3]
  
  * release notes for
@@@ -881,19 -876,21 +881,21 @@@ othe
        and the `core.editor` option in linkgit:git-config[1].
  
  'GIT_SSH'::
-       If this environment variable is set then 'git fetch'
-       and 'git push' will use this command instead
-       of 'ssh' when they need to connect to a remote system.
-       The '$GIT_SSH' command will be given exactly two or
-       four arguments: the 'username@host' (or just 'host')
-       from the URL and the shell command to execute on that
-       remote system, optionally preceded by '-p' (literally) and
-       the 'port' from the URL when it specifies something other
-       than the default SSH port.
+ 'GIT_SSH_COMMAND'::
+       If either of these environment variables is set then 'git fetch'
+       and 'git push' will use the specified command instead of 'ssh'
+       when they need to connect to a remote system.
+       The command will be given exactly two or four arguments: the
+       'username@host' (or just 'host') from the URL and the shell
+       command to execute on that remote system, optionally preceded by
+       '-p' (literally) and the 'port' from the URL when it specifies
+       something other than the default SSH port.
  +
- To pass options to the program that you want to list in GIT_SSH
- you will need to wrap the program and options into a shell script,
- then set GIT_SSH to refer to the shell script.
+ `$GIT_SSH_COMMAND` takes precedence over `$GIT_SSH`, and is interpreted
+ by the shell, which allows additional arguments to be included.
+ `$GIT_SSH` on the other hand must be just the path to a program
+ (which can be a wrapper shell script, if additional arguments are
+ needed).
  +
  Usually it is easier to configure any desired options through your
  personal `.ssh/config` file.  Please consult your ssh documentation