* rh/prompt-pcmode-avoid-eval-on-refname:
  git-prompt.sh: don't assume the shell expands the value of PS1

Not all shells subject the prompt string to parameter expansion.  Test
whether the shell will expand the value of PS1, and use the result to
control whether raw ref names are included directly in PS1.

This fixes a regression introduced in commit 8976500 ("git-prompt.sh:
don't put unsanitized branch names in $PS1"):  zsh does not expand PS1
by default, but that commit assumed it did.  The bug resulted in
prompts containing the literal string '${__git_ps1_branch_name}'
instead of the actual branch name.

Reported-by: Caleb Thompson <caleb@calebthompson.io>
Signed-off-by: Richard Hansen <rhansen@bbn.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* fc/prompt-zsh-read-from-file:
  contrib: completion: fix 'eread()' namespace

Otherwise it might collide with a function of the same name in the
user's environment.

Suggested-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* rh/prompt-pcmode-avoid-eval-on-refname:
  git-prompt.sh: don't put unsanitized branch names in $PS1

Both bash and zsh subject the value of PS1 to parameter expansion,
command substitution, and arithmetic expansion.  Rather than include
the raw, unescaped branch name in PS1 when running in two- or
three-argument mode, construct PS1 to reference a variable that holds
the branch name.  Because the shells do not recursively expand, this
avoids arbitrary code execution by specially-crafted branch names such
as '$(IFS=_;cmd=sudo_rm_-rf_/;$cmd)'.

Signed-off-by: Richard Hansen <rhansen@bbn.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* fc/complete-aliased-push:
  completion: fix completing args of aliased "push", "fetch", etc.

zsh seems to have a bug while redirecting the stderr of the 'read'
command:

    % read foo 2>/dev/null <foo
    zsh: no such file or directory: foo

Which causes errors to be displayed when certain files are missing.
Let's add a convenience function to manually check if the file is
readable before calling "read".

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Some commands need the first word to determine the actual action that is
being executed, however, the command is wrong when we use an alias, for
example 'alias.p=push', if we try to complete 'git p origin ', the
result would be wrong because __git_complete_remote_or_refspec() doesn't
know where it came from.

So let's override words[1], so the alias 'p' is override by the actual
command, 'push'.

Reported-by: Aymeric Beaumet <aymeric.beaumet@gmail.com>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

* ss/completion-rec-sub-fetch-push:
  completion: teach --recurse-submodules to fetch, pull and push