Commit Graph

84 Commits

Author SHA1 Message Date
David J. Malan
e8882a87d9 git-prompt: change == to = for zsh's sake
When using git-prompt.sh with zsh, __git_ps1 currently errs
when inside a repo with:

__git_ps1:96: = not found

Avoid using non-portable "==" that is only understood by bash
and not zsh. Change to "=" so that the prompt script becomes
usable with zsh again.

Signed-off-by: David J. Malan <malan@harvard.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-20 17:37:20 -07:00
Elijah Newren
afda36dbf3 git-prompt: include sparsity state as well
git-prompt includes the current branch, a bunch of single character
mini-state displayers, and some much longer in-progress state
notifications.  The current branch is always shown.  The single
character mini-state displayers are all off by default (they are not
self explanatory) but each has an environment variable for turning it
on.  The in-progress state notifications provide no configuration
options for turning them off, and can be up to 15 characters long (e.g.
"|REBASE (12/18)" or "|CHERRY-PICKING").

The single character mini-state tends to be used for things like "Do you
have any stashes in refs/stash?" or "Are you ahead or behind of
upstream?".  These are things which users can take advantage of but do
not affect most normal git operations.  The in-progress states, by
contrast, suggest the user needs to interact differently and may also
prevent some normal operations from succeeding (e.g. git switch may show
an error instead of switching branches).

Sparsity is like the in-progress states in that it suggests a
fundamental different interaction with the repository (many of the files
from the repository are not present in your working copy!).  A few
commits ago added sparsity information to wt_longstatus_print_state(),
grouping it with other in-progress state displays.  We do similarly here
with the prompt and show the extra state, by default, with an extra
    |SPARSE
This state can be present simultaneously with the in-progress states, in
which case it will appear before the other states; for example,
    (branchname|SPARSE|REBASE 6/10)

The reason for showing the "|SPARSE" substring before other states is to
emphasize those other states.  Sparsity is probably not going to change
much within a repository, while temporary operations will.  So we want
the state changes related to temporary operations to be listed last, to
make them appear closer to where the user types and make them more
likely to be noticed.

The fact that sparsity isn't just cached metadata or additional
information is what leads us to show it more similarly to the
in-progress states, but the fact that sparsity is not transient like the
in-progress states might cause some users to want an abbreviated
notification of sparsity state or perhaps even be able to turn it off.
Allow GIT_PS1_COMPRESSSPARSESTATE to be set to request that it be
shortened to a single character ('?'), and GIT_PS1_OMITSPARSESTATE to be
set to request that sparsity state be omitted from the prompt entirely.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-22 09:29:59 -07:00
Elijah Newren
30b00f009c git-prompt: document how in-progress operations affect the prompt
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-22 09:29:59 -07:00
Elijah Newren
6d04ce75c4 git-prompt: change the prompt for interactive-based rebases
In the past, we had different prompts for different types of rebases:
   REBASE: for am-based rebases
   REBASE-m: for merge-based rebases
   REBASE-i: for interactive-based rebases

It's not clear why this distinction was necessary or helpful; when the
prompt was added in commit e75201963f ("Improve bash prompt to detect
various states like an unfinished merge", 2007-09-30), it simply added
these three different types.  Perhaps there was a useful purpose back
then, but there have been some changes:

  * The merge backend was deleted after being implemented on top of the
    interactive backend, causing the prompt for merge-based rebases to
    change from REBASE-m to REBASE-i.
  * The interactive backend is used for multiple different types of
    non-interactive rebases, so the "-i" part of the prompt doesn't
    really mean what it used to.
  * Rebase backends have gained more abilities and have a great deal of
    overlap, sometimes making it hard to distinguish them.
  * Behavioral differences between the backends have also been ironed
    out.
  * We want to change the default backend from am to interactive, which
    means people would get "REBASE-i" by default if we didn't change
    the prompt, and only if they specified --am or --whitespace or -C
    would they get the "REBASE" prompt.
  * In the future, we plan to have "--whitespace", "-C", and even "--am"
    run the interactive backend once it can handle everything the
    am-backend can.

For all these reasons, make the prompt for any type of rebase just be
"REBASE".

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-16 15:40:42 -08:00
Phillip Wood
e981bf7525 git-prompt: improve cherry-pick/revert detection
If the user commits or resets a conflict resolution in the middle of a
sequence of cherry-picks or reverts then CHERRY_PICK_HEAD/REVERT_HEAD
will be removed and so in the absence of those files we need to check
.git/sequencer/todo to see if there is a cherry-pick or revert in
progress.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-01 12:39:44 -07:00
Robert Abel
041fe8fc83 git-prompt: fix reading files with windows line endings
If any of the files read by __git_eread have \r\n line endings, read
will only strip \n, leaving \r. This results in an ugly prompt, where
instead of

    user@pc MINGW64 /path/to/repo (BARE:master)

the last parenthesis is printed over the beginning of the prompt like

    )ser@pc MINGW64 /path/to/repo (BARE:master

This patch fixes the issue by changing the internal field separator
variable IFS to $'\r\n' before using the read builtin command.

Note that ANSI-C Quoting/POSIX Quoting ($'...') is supported by bash
as well as zsh, which are the current targets of git-prompt, cf.
contrib/completion/git-prompt.sh.

Signed-off-by: Robert Abel <rabel@robertabel.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-06 10:08:13 -08:00
Robert Abel
5501f500b2 git-prompt: make __git_eread intended use explicit
__git_eread is used to read a single line of a given file (if it exists)
into a single variable stripping the EOL.
This patch removes the unused capability to split file contents into tokens
by passing multiple variable names. Add a comment and explicitly use $2
instead of misleading $@ as argument to the read builtin command.

Signed-off-by: Robert Abel <rabel@robertabel.eu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-06 10:08:12 -08:00
Michael J Gruber
9f0b4dd0b8 git-prompt: add a describe style for any tags
git-prompt has various describe styles, among them "describe" (by
annotated tags) and "default" (by exact match with any tag).

Add a mode "tag" that describes by any tag, annotated or not.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-15 13:19:41 -07:00
Junio C Hamano
be099661f4 Merge branch 'vs/prompt-avoid-unset-variable'
The git-prompt scriptlet (in contrib/) was not friendly with those
who uses "set -u", which has been fixed.

* vs/prompt-avoid-unset-variable:
  git-prompt.sh: Don't error on null ${ZSH,BASH}_VERSION, $short_sha
2016-06-27 09:56:47 -07:00
Ville Skyttä
34d8f5a8aa git-prompt.sh: Don't error on null ${ZSH,BASH}_VERSION, $short_sha
When the shell is in "nounset" or "set -u" mode, referencing unset or
null variables results in an error. Protect $ZSH_VERSION and
$BASH_VERSION against that, and initialize $short_sha before use.

Signed-off-by: Ville Skyttä <ville.skytta@iki.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-06 13:09:07 -07:00
SZEDER Gábor
c26f70ceb3 bash prompt: indicate dirty index even on orphan branches
__git_ps1() doesn't indicate dirty index while on an orphan branch.

To check the dirtiness of the index, __git_ps1() runs 'git diff-index
--cached ... HEAD', which doesn't work on an orphan branch,
because HEAD doesn't point to a valid commit.

Run 'git diff ... --cached' instead, as it does the right thing both
on valid and invalid HEAD, i.e. compares the index to the existing
HEAD in the former case and to the empty tree in the latter.  This
fixes the two failing tests added in the first commit of this series.

The dirtiness of the worktree is already checked with 'git diff' and
is displayed correctly even on an orphan branch.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-24 15:27:01 -05:00
SZEDER Gábor
0af9f7ecb8 bash prompt: remove a redundant 'git diff' option
To get the dirty state indicator __git_ps1() runs 'git diff' with
'--quiet --exit-code' options.  '--quiet' already implies
'--exit-code', so the latter is unnecessary and can be removed.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-24 15:27:01 -05:00
SZEDER Gábor
dd160d794f bash prompt: faster untracked status indicator with untracked directories
If the untracked status indicator is enabled, __git_ps1() looks for
untracked files by running 'git ls-files'.  This can be perceptibly slow
in case of an untracked directory containing lot of files, because it
lists all files found in the untracked directory only to be redirected
into /dev/null right away (this is the actual command run by __git_ps1()):

  $ ls untracked-dir/ |wc -l
  100000
  $ time git ls-files --others --exclude-standard --error-unmatch \
    -- ':/*' >/dev/null 2>/dev/null

  real	0m0.955s
  user	0m0.936s
  sys	0m0.016s

Eliminate this delay by additionally passing the '--directory
--no-empty-directory' options to 'git ls-files' to show only the name of
non-empty untracked directories instead of all their content:

  $ time git ls-files --others --exclude-standard --directory \
    --no-empty-directory --error-unmatch -- ':/*' >/dev/null 2>/dev/null

  real	0m0.010s
  user	0m0.008s
  sys	0m0.000s

This follows suit of ea95c7b8f5 (completion: improve untracked directory
filtering for filename completion, 2013-09-18).

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-20 13:08:56 -07:00
Junio C Hamano
51d5980ea0 Merge branch 'jc/prompt-document-ps1-state-separator' into maint
Docfix.

* jc/prompt-document-ps1-state-separator:
  git-prompt.sh: document GIT_PS1_STATESEPARATOR
2015-07-15 11:41:26 -07:00
Junio C Hamano
d70bc3b97a Merge branch 'jc/prompt-document-ps1-state-separator'
Docfix.

* jc/prompt-document-ps1-state-separator:
  git-prompt.sh: document GIT_PS1_STATESEPARATOR
2015-07-01 14:02:32 -07:00
Joe Cridge
ab7fade919 git-prompt.sh: document GIT_PS1_STATESEPARATOR
The environment variable GIT_PS1_STATESEPARATOR can be used to set the
separator between the branch name and the state symbols in the prompt.

At present the variable is not mentioned in the inline documentation which
makes it difficult for the casual user to identify.

Signed-off-by: Joe Cridge <joe.cridge@me.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-10 14:53:14 -07:00
Junio C Hamano
5f15cba2f9 Merge branch 'ct/prompt-untracked-fix'
The prompt script (in contrib/) did not show the untracked sign
when working in a subdirectory without any untracked files.

* ct/prompt-untracked-fix:
  git prompt: use toplevel to find untracked files
2015-03-25 12:54:18 -07:00
Cody A Taylor
9bdc5173f0 git prompt: use toplevel to find untracked files
The __git_ps1() prompt function would not show an untracked state
when all the untracked files are outside the current working
directory.

Signed-off-by: Cody A Taylor <codemister99@yahoo.com>
Helped-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-15 14:23:22 -07:00
Junio C Hamano
9920c71825 Merge branch 'tf/prompt-preserve-exit-status'
Using the exit status of the last command in the prompt, e.g.
PS1='$(__git_ps1) $? ', did not work well because the helper
function stomped on the exit status.

* tf/prompt-preserve-exit-status:
  git-prompt: preserve value of $? in all cases
2015-01-14 12:35:49 -08:00
Junio C Hamano
e1ef7d177c Merge branch 'rh/hide-prompt-in-ignored-directory'
* rh/hide-prompt-in-ignored-directory:
  git-prompt.sh: allow to hide prompt for ignored pwd
  git-prompt.sh: if pc mode, immediately set PS1 to a plain prompt
2015-01-14 12:34:01 -08:00
Tony Finch
6babe76496 git-prompt: preserve value of $? in all cases
Signed-off-by: Tony Finch <dot@dotat.at>
Reviewed-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-01-14 10:11:49 -08:00
Junio C Hamano
487b17de3e Merge branch 'tf/prompt-preserve-exit-status'
Using the exit status of the last command in the prompt, e.g.
PS1='$(__git_ps1) $? ', did not work well because the helper
function stomped on the exit status.

* tf/prompt-preserve-exit-status:
  git-prompt: preserve value of $? inside shell prompt
2015-01-07 13:09:35 -08:00
Jess Austin
0120b8c85c git-prompt.sh: allow to hide prompt for ignored pwd
Optionally set __git_ps1 to display nothing when present working
directory is ignored, triggered by the new environment variable
GIT_PS1_HIDE_IF_PWD_IGNORED. This environment variable may be
overridden on any repository by setting bash.hideIfPwdIgnored to
"false". In the absence of GIT_PS1_HIDE_IF_PWD_IGNORED this change
has no effect.

Many people manage e.g. dotfiles in their home directory with git.
This causes the prompt generated by __git_ps1 to refer to that "top
level" repo while working in any descendant directory. That can be
distracting, so this patch helps one shut off that noise.

Signed-off-by: Jess Austin <jess.austin@gmail.com>
Signed-off-by: Richard Hansen <rhansen@bbn.com>
Reviewed-by: Richard Hansen <rhansen@bbn.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-01-07 10:30:30 -08:00
Richard Hansen
76b4309400 git-prompt.sh: if pc mode, immediately set PS1 to a plain prompt
At the beginning of __git_ps1, right after determining that the
function is running in pc mode, set PS1 to a plain (undecorated)
prompt.  This makes it possible to simply return early without having
to set PS1 if the prompt should not be decorated.

Signed-off-by: Richard Hansen <rhansen@bbn.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-01-07 10:27:53 -08:00
Junio C Hamano
35b5a8b769 Merge branch 'jg/prompt-localize-temporary'
"git-prompt" (in contrib/) used a variable from the global scope,
possibly contaminating end-user's namespace.

* jg/prompt-localize-temporary:
  git-prompt.sh: make $f local to __git_eread()
2014-12-22 12:28:20 -08:00
Tony Finch
eb443e3b39 git-prompt: preserve value of $? inside shell prompt
If you have a prompt which displays the command exit status,
__git_ps1 without this change corrupts it, although it has
the correct value in the parent shell:

	~/src/git (master) 0 $ set | grep ^PS1
	PS1='\w$(__git_ps1) $? \$ '
	~/src/git (master) 0 $ false
	~/src/git (master) 0 $ echo $?
	1
	~/src/git (master) 0 $

There is a slightly ugly workaround:

	~/src/git (master) 0 $ set | grep ^PS1
	PS1='\w$(x=$?; __git_ps1; exit $x) $? \$ '
	~/src/git (master) 0 $ false
	~/src/git (master) 1 $

This change makes the workaround unnecessary.

Signed-off-by: Tony Finch <dot@dotat.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-22 11:58:56 -08:00
Justin Guenther
9dd70e0a0d git-prompt.sh: make $f local to __git_eread()
This function uses (non-local) $f to store the value of its first parameter.
This can interfere with the user's environment.

Signed-off-by: Justin Guenther <jguenther@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-12 15:13:37 -08:00
Jeff King
0fa7f01635 git-prompt: do not look for refs/stash in $GIT_DIR
Since dd0b72c (bash prompt: use bash builtins to check stash
state, 2011-04-01), git-prompt checks whether we have a
stash by looking for $GIT_DIR/refs/stash. Generally external
programs should never do this, because they would miss
packed-refs.

That commit claims that packed-refs does not pack
refs/stash, but that is not quite true. It does pack the
ref, but due to a bug, fails to prune the ref. When we fix
that bug, we would want to be doing the right thing here.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-25 12:21:17 -07:00
Junio C Hamano
df43b41afc Merge branch 'rh/prompt-pcmode-avoid-eval-on-refname'
* rh/prompt-pcmode-avoid-eval-on-refname:
  git-prompt.sh: don't assume the shell expands the value of PS1
2014-05-19 16:10:10 -07:00
Richard Hansen
1e4119c81b 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>
2014-05-19 16:09:53 -07:00
Junio C Hamano
6308767f0b Merge branch 'fc/prompt-zsh-read-from-file'
* fc/prompt-zsh-read-from-file:
  contrib: completion: fix 'eread()' namespace
2014-05-13 11:53:14 -07:00
Felipe Contreras
66ab301c16 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>
2014-05-13 11:52:51 -07:00
Junio C Hamano
f7003da0f4 Merge branch 'rh/prompt-pcmode-avoid-eval-on-refname'
* rh/prompt-pcmode-avoid-eval-on-refname:
  git-prompt.sh: don't put unsanitized branch names in $PS1
2014-05-02 13:10:53 -07:00
Richard Hansen
8976500cbb 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>
2014-04-22 12:37:53 -07:00
Felipe Contreras
59d3924fbb prompt: fix missing file errors in zsh
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>
2014-04-14 13:27:23 -07:00
Junio C Hamano
9f279af862 Merge branch 'sg/prompt-svn-remote-fix'
Bash portability fix.

* sg/prompt-svn-remote-fix:
  bash prompt: don't use '+=' operator in show upstream code path
2013-10-28 10:43:38 -07:00
SZEDER Gábor
52ec889d1a bash prompt: don't use '+=' operator in show upstream code path
The '+=' operator is not supported by old Bash versions (3.0) we still
care about.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-10-15 14:20:37 -07:00
Julien Carsique
1f6806cf2d git-prompt.sh: optionally show upstream branch name
When working with multiple remotes, it is common to switch the upstream
from a remote to another. Doing so, the prompt may not be the expected
one. Providing an option to display tracking information sounds useful.

Add a "name" option to GIT_PS1_SHOWUPSTREAM which will show the upstream
abbrev name. This option is ignored if "verbose" is false.

Signed-off-by: Julien Carsique <julien.carsique@gmail.com>
Improved-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-10-14 10:24:34 -07:00
Brandon Casey
a44aa6930c contrib/git-prompt.sh: handle missing 'printf -v' more gracefully
Old Bash (3.0) which is distributed with RHEL 4.X and other ancient
platforms that are still in wide use, do not have a printf that
supports -v.  Neither does Zsh (which is already handled in the code).

As suggested by Junio, let's test whether printf supports the -v
option and store the result.  Then later, we can use it to
determine whether 'printf -v' can be used, or whether printf
must be called in a subshell.

Signed-off-by: Brandon Casey <drafnel@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-22 09:50:16 -07:00
Junio C Hamano
46b045917c Merge branch 'ed/color-prompt'
Code clean-up for in-prompt status script (in contrib/).

* ed/color-prompt:
  git-prompt.sh: add missing information in comments
  git-prompt.sh: do not print duplicate clean color code
  t9903: remove redundant tests
  git-prompt.sh: refactor colored prompt code
  t9903: add tests for git-prompt pcmode
2013-07-01 12:41:55 -07:00
Eduardo R. D'Avila
cf4cac4cfc git-prompt.sh: add missing information in comments
Mention that the command below is needed for prompt
in ZSH with PS1:
  setopt PROMPT_SUBST

Rephrase some parts that mention only the "current branch name"
being displayed in the prompt. Replace it by stating that
the "repository status" is displayed.

Make it clear that colored prompt is only available
in PROMPT_COMMAND/precmd mode.

With-suggestions-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Eduardo R. D'Avila <erdavila@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-26 13:03:01 -07:00
Eduardo R. D'Avila
15981f4eec git-prompt.sh: do not print duplicate clean color code
Do not print a duplicate clean color code when there
is no other indicators other than the current branch
in colored prompt.

Acked-by: SZEDER Gábor <szeder@ira.uka.de>
Signed-off-by: Eduardo R. D'Avila <erdavila@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-26 13:03:01 -07:00
Eduardo R. D'Avila
7fe9031920 git-prompt.sh: refactor colored prompt code
__git_ps1_colorize_gitstring() sets color codes and
builds the prompt gitstring. It has duplicated code
to handle color codes for bash and zsh shells.
__git_ps1() also has duplicated logic to build the
prompt gitstring.

Remove duplication of logic to build gitstring in
__git_ps1_colorize_gitstring() and __git_ps1().

Leave in __git_ps1_colorize_gitstring() only logic
to set color codes.

Signed-off-by: Eduardo R. D'Avila <erdavila@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-06-26 13:02:57 -07:00
SZEDER Gábor
a694258457 bash prompt: mention that PROMPT_COMMAND mode is faster
__git_ps1() is usually added to the prompt inside a command
substitution, imposing the overhead of fork()ing a subshell.  Using
__git_ps1() for $PROMPT_COMMAND is slightly faster, because it avoids
that command substitution.

Mention this in the comments about setting up the git prompt.

The whole series speeds up the bash prompt on Windows/MSysGit
considerably.  Here are some timing results in three scenarios, each
repeated 10 times:

At the top of the work tree, before:

    $ time for i in {0..9} ; do prompt="$(__git_ps1)" ; done

    real    0m1.716s
    user    0m0.301s
    sys     0m0.772s

  After:

    real    0m0.687s
    user    0m0.075s
    sys     0m0.396s

  After, from $PROMPT_COMMAND:

    $ time for i in {0..9} ; do __git_ps1 '\h:\w' '$ ' ; done

    real    0m0.546s
    user    0m0.075s
    sys     0m0.181s

At the top of the work tree, detached head, before:

    real    0m2.574s
    user    0m0.376s
    sys     0m1.207s

  After:

    real    0m1.139s
    user    0m0.151s
    sys     0m0.500s

  After, from $PROMPT_COMMAND:

    real    0m1.030s
    user    0m0.245s
    sys     0m0.336s

In a subdirectory, during rebase, stash status indicator enabled,
before:

    real    0m3.557s
    user    0m0.495s
    sys     0m1.767s

  After:

    real    0m0.717s
    user    0m0.120s
    sys     0m0.300s

  After, from $PROMPT_COMMAND:

    real    0m0.577s
    user    0m0.047s
    sys     0m0.258s

On Linux the speedup ratio is comparable to Windows, but overall it
was about an order of magnitude faster to begin with.  The last case
from above, repeated 100 times, before:

    $ time for i in {0..99} ; do prompt="$(__git_ps1)" ; done

    real    0m2.806s
    user    0m0.180s
    sys     0m0.264s

  After:

    real    0m0.857s
    user    0m0.020s
    sys     0m0.028s

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
2013-06-24 18:03:37 +02:00
SZEDER Gábor
69a8141a5d bash prompt: avoid command substitution when finalizing gitstring
Before setting $PS1, __git_ps1() uses a command substitution to
redirect the output from a printf into a variable.  Spare the overhead
of fork()ing a subshell by using 'printf -v <var>' to directly assign
the output to that variable.

zsh's printf doesn't support the '-v <var>' option, so stick with the
command substitution when under zsh.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
2013-06-24 18:03:37 +02:00
SZEDER Gábor
14d7649748 bash prompt: avoid command substitution when checking for untracked files
When enabled, the bash prompt can indicate the presence of untracked
files with a '%' sign.  __git_ps1() checks for untracked files by running the
'$(git ls-files --others --exclude-standard)' command substitution,
and displays the indicator when there is no output.

Avoid this command substitution by additionally passing
'--error-unmatch *', and checking the command's return value.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
2013-06-24 18:03:37 +02:00
SZEDER Gábor
dd0b72cbd9 bash prompt: use bash builtins to check stash state
When the environment variable $GIT_PS1_SHOWSTASHSTATE is set
__git_ps1() checks the presence of stashes by running 'git rev-parse
--verify refs/stash'.  This command not only checks that the
'refs/stash' ref exists but also, well, verifies that it's a valid
ref.

However, we don't need to be that thorough for the bash prompt.  We
can omit that verification and only check whether 'refs/stash' exists
or not.  Since 'git pack-refs' never packs 'refs/stash', it's a matter
of checking the existence of a ref file.  Perform this check using
only bash builtins to spare the overhead of fork()+exec()ing a git
process.

Also run 'git pack-refs --all' in the corresponding test to document
that the prompt script depends on 'git pack-refs' not packing
'refs/stash' and to catch possible breakages should this behavior ever
change.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
2013-06-24 18:03:37 +02:00
SZEDER Gábor
0f37c12581 bash prompt: use bash builtins to check for unborn branch for dirty state
When the dirty work tree and index status indicator is enabled,
__git_ps1() checks for changes in the index by running 'git diff-index
--cached --quiet HEAD --' and looking at its exit code.  However, that
makes sense only when HEAD points to a valid commit: on an unborn
branch the failure of said command would be caused by the invalid
HEAD, not by changes in the index.  Therefore, __git_ps1() first
checks for a valid HEAD by running 'git rev-parse --quiet --verify
HEAD'.

Since the previous patch we implicitly check HEAD's validity by
running 'git rev-parse ... --short HEAD', making the dirty status
indicator's 'git rev-parse' check redundant.  It's sufficient to check
for non-emptyness of the variable holding the abbreviated commit
object name, thereby sparing the overhead of fork()+exec()ing a git
process.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
2013-06-24 18:03:37 +02:00
SZEDER Gábor
e3e0b9378b bash prompt: combine 'git rev-parse' for detached head
When describing a detached HEAD according to the $GIT_PS1_DESCRIBE
environment variable fails, __git_ps1() now runs the '$(git rev-parse
--short HEAD)' command substitution to get the abbreviated detached
HEAD commit object name.  This imposes the overhead of fork()ing a
subshell and fork()+exec()ing a git process.

Avoid this overhead by combining this command substitution with the
"main" 'git rev-parse' execution for getting the path to the .git
directory & co.  This means that we'll look for the abbreviated commit
object name even when it's not necessary, because we're on a branch or
the detached HEAD can be described.  It doesn't matter, however,
because once 'git rev-parse' is up and running to fulfill all those
other queries, the additional overhead of looking for the abbreviated
commit object name is not measurable because it's lost in the noise.

There is a caveat, however, when we are on an unborn branch, because
in that case HEAD doesn't point to a valid commit, hence the query for
the abbreviated commit object name fails.  Therefore, '--short HEAD'
must be the last options to 'git rev-parse' in order to get all the
other necessary information for the prompt even on an unborn branch.
Furthermore, in that case, and in that case only, 'git rev-parse'
doesn't output the last line containing the abbreviated commit object
name, obviously, so we have to take care to only parse it if 'git
rev-parse' exited without any error.

Although there are tests already excercising __git_ps1() on unborn
branches, they all do so implicitly.  Add a test that checks this
explicitly.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
2013-06-24 18:03:30 +02:00
SZEDER Gábor
efaa0c1532 bash prompt: combine 'git rev-parse' executions in the main code path
There are a couple of '$(git rev-parse --<opt>)' command substitutions
in __git_ps1() and three of them are executed in the main code path:

 - the first to get the path to the .git directory ('--git-dir'),
 - the second to check whether we're inside the .git directory
   ('--is-inside-git-dir'),
 - and the last, depending on the results of the second, either
   * to check whether it's a bare repo ('--is-bare-repository'), or
   * to check whether inside a work tree ('--is-inside-work-tree').

Naturally, this imposes the overhead of fork()ing three subshells and
fork()+exec()ing three git commands.

Combine these four 'git rev-parse' queries into a single one and use
bash parameter expansions to parse the combined output, i.e. to
separate the path to the .git directory from the true/false of
'--is-inside-git-dir', etc.  This way we can eliminate two of the
three subshells and git commands.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
2013-06-24 17:22:10 +02:00