add: update pathless 'add [-u|-A]' warning to reflect change of plan

We originally thought the transition would need a period where "git add
[-u|-A]" without pathspec would be forbidden, but the warning is big
enough to scare people and teach them not to use it (or, if so, to
understand the consequences).

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'gp/add-u-A-documentation'

* gp/add-u-A-documentation:
  add: Clarify documentation of -A and -u
git-completion.bash: zsh does not implement function redirection correctly

A recent change added functions whose entire standard error stream
is redirected to /dev/null using a construct that is valid POSIX.1
but is not widely used:

	funcname () {
		cd "$1" && run some command "$2"
	} 2>/dev/null

Even though this file is "git-completion.bash", zsh completion
support dot-sources it (instead of asking bash to grok it like tcsh
completion does), and zsh does not implement this redirection
correctly.

With zsh, trying to complete an inexistant directory gave this:

  git add no-such-dir/__git_ls_files_helper:cd:2: no such file or directory: no-such-dir/

Also these functions use "cd" to first go somewhere else before
running a command, but the location the caller wants them to go that
is given as an argument to them should not be affected by CDPATH
variable the users may have set for their interactive session.

To fix both of these, wrap the body of the function in a subshell,
unset CDPATH at the beginning of the subshell, and redirect the
standard error stream of the subshell to /dev/null.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'mm/add-u-A-finishing-touches'

* mm/add-u-A-finishing-touches:
  add: update pathless 'add [-u|-A]' warning to reflect change of plan
Merge branch 'mp/complete-paths'

* mp/complete-paths:
  git-completion.bash: zsh does not implement function redirection correctly
git.c: make usage match manual page

Reorder option list in command-line usage to match the manual page.
Also make it less than 80-characters wide.

Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'maint'

* maint:
  git.c: make usage match manual page
Merge branch 'master' into next

* master:
  git.c: make usage match manual page
  git-completion.bash: zsh does not implement function redirection correctly
  add: update pathless 'add [-u|-A]' warning to reflect change of plan