Subject: Re: [PATCH v7] git-prompt: make colourization consistent

From: SZEDER Gábor <[email-masked]>
Date: Thu, 9 Jun 2022 11:03:02 +0200

On Tue, Jun 07, 2022 at 01:50:24PM +0200, Joakim Petersen wrote:
> The short upstream state indicator inherits the colour of the last short
> state indicator before it (if there is one), and the sparsity state
> indicator inherits this colour as well. This behaviour was introduced by
> 0ec7c23cdc6 (git-prompt: make upstream state indicator location
> consistent, 2022-02-27), while before this change the aforementioned
> indicators were white/the default text colour. Some examples to
> illustrate this behaviour (assuming all indicators are enabled and
> colourization is on):
>  * If there is something in the stash, both the '$' and the short
>    upstream state indicator following it will be blue.
>  * If the local tree has new, untracked files and there is nothing in
>    the stash, both the '%' and the short upstream state indicator
>    will be red.
>  * If all local changes are added to the index and the stash is empty,
>    both the '+' and the short upstream state indicator following it will
>    be green.
>  * If the local tree is clean and there is nothing in the stash, the
>    short upstream state indicator will be white/${default text colour}.
> 
> This appears to be an unintended side-effect of the change, and makes
> little sense semantically (e.g. why is it bad to be in sync with
> upstream when you have uncommitted local changes?). The cause of the
> change in colourization is that previously, the short upstream state
> indicator appeared immediately after the rebase/revert/bisect/merge
> state indicator (note the position of $p in $gitstring):
> 
> 	local f="$h$w$i$s$u"
> 	local gitstring="$c$b${f:+$z$f}${sparse}$r$p"
> 	
> Said indicator is prepended with the clear colour code, and the short
> upstream state indicator is thus also uncoloured. Now, the short
> upstream state indicator follows the sequence of colourized indicators,
> without any clearing of colour (again note the position of $p, now in
> $f):
> 
> 	local f="$h$w$i$s$u$p"
> 	local gitstring="$c$b${f:+$z$f}${sparse}$r${upstream}"
> 
> If the user is in a sparse checkout, the sparsity state indicator
> follows a similar pattern to the short upstream state indicator.
> However, clearing colour of the colourized indicators changes how the
> sparsity state indicator is colourized, as it currently inherits (and
> before the change referenced also inherited) the colour of the last
> short state indicator before it. Reading the commit message of the
> change that introduced the sparsity state indicator, afda36dbf3b
> (git-prompt: include sparsity state as well, 2020-06-21), it appears
> this colourization also was unintended, so clearing the colour for said
> indicator further increases consistency.
> 
> Make the colourization of these state indicators consistent by making
> all colourized indicators clear their own colour. Make colouring of $c
> dependent on it not being empty, as it is no longer being used to colour
> the branch name. Move clearing of $b's prefix to before colourization so
> it gets cleared properly when colour codes are inserted into it. These
> changes make changing the layout of the prompt less prone to unintended
> colour changes in the future.
> 
> Change coloured Bash prompt tests to reflect the colourization changes:
>  * Move the colour codes to wrap the expected content of the expanded
>    $__git_ps1_branch_name in all tests.
>  * Insert a clear-colour code after the symbol for the first indicator
>    in "prompt - bash color pc mode - dirty status indicator - dirty
>    index and worktree", to reflect that all indicators should clear
>    their own colour.

This patch seems to break colorization when __git_ps1() is invoked
from $PROMPT_COMMAND:

  ~/src/git (master)$ echo $PROMPT_COMMAND 
__git_ps1 "\[\e]0;\w - Terminal\a\e[01;32m\]\h\[\e[01;34m\] \w" "\[\e[01;34m\]\$\[\e[00m\] " " \[\e[01;34m\](%s\[\e[01;34m\])"
  ~/src/git (master)$ git checkout 9470605a1b
  HEAD is now at 9470605a1b git-prompt: make colourization consistent
  ~/src/git ((9470605a1b...))$ source contrib/completion/git-prompt.sh 
  ~/src/git (\[\e[31m\](9470605a1b...)\[\e[0m\])$ # uh-oh
  ~/src/git (\[\e[31m\](9470605a1b...)\[\e[0m\])$ git checkout 9470605a1b^
  Previous HEAD position was 9470605a1b git-prompt: make colourization consistent
  HEAD is now at 2668e3608e Sixth batch
  ~/src/git (\[\e[31m\](2668e3608e...)\[\e[0m\])$ source contrib/completion/git-prompt.sh 
  ~/src/git ((2668e3608e...))$ # Looks good.

> Signed-off-by: Joakim Petersen <[email-masked]>
> ---
> Changes since v6:
>  * Remove repeated statements and move all explanation of what the patch
>    does to the latter part of the message.
>  * Add a short statement about other benefits of the behavioural change.
> 
> Range-diff against v6:
> 1:  50765eeb95 = 1:  e25738c667 git-prompt: make colourization consistent
> 
>  contrib/completion/git-prompt.sh | 22 ++++++++++++----------
>  t/t9903-bash-prompt.sh           | 18 +++++++++---------
>  2 files changed, 21 insertions(+), 19 deletions(-)
> 
> diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
> index 87b2b916c0..cb01c2fd5d 100644
> --- a/contrib/completion/git-prompt.sh
> +++ b/contrib/completion/git-prompt.sh
> @@ -245,7 +245,8 @@ __git_ps1_show_upstream ()
>  
>  # Helper function that is meant to be called from __git_ps1.  It
>  # injects color codes into the appropriate gitstring variables used
> -# to build a gitstring.
> +# to build a gitstring. Colored variables are responsible for clearing
> +# their own color.
>  __git_ps1_colorize_gitstring ()
>  {
>  	if [[ -n ${ZSH_VERSION-} ]]; then
> @@ -271,22 +272,23 @@ __git_ps1_colorize_gitstring ()
>  	else
>  		branch_color="$bad_color"
>  	fi
> -	c="$branch_color$c"
> +	if [ -n "$c" ]; then
> +		c="$branch_color$c$c_clear"
> +	fi
> +	b="$branch_color$b$c_clear"
>  
> -	z="$c_clear$z"
> -	if [ "$w" = "*" ]; then
> -		w="$bad_color$w"
> +	if [ -n "$w" ]; then
> +		w="$bad_color$w$c_clear"
>  	fi
>  	if [ -n "$i" ]; then
> -		i="$ok_color$i"
> +		i="$ok_color$i$c_clear"
>  	fi
>  	if [ -n "$s" ]; then
> -		s="$flags_color$s"
> +		s="$flags_color$s$c_clear"
>  	fi
>  	if [ -n "$u" ]; then
> -		u="$bad_color$u"
> +		u="$bad_color$u$c_clear"
>  	fi
> -	r="$c_clear$r"
>  }
>  
>  # Helper function to read the first line of a file into a variable.
> @@ -554,6 +556,7 @@ __git_ps1 ()
>  		fi
>  	fi
>  
> +	b=${b##refs/heads/}
>  	local z="${GIT_PS1_STATESEPARATOR-" "}"
>  
>  	# NO color option unless in PROMPT_COMMAND mode or it's Zsh
> @@ -563,7 +566,6 @@ __git_ps1 ()
>  		fi
>  	fi
>  
> -	b=${b##refs/heads/}
>  	if [ $pcmode = yes ] && [ $ps1_expanded = yes ]; then
>  		__git_ps1_branch_name=$b
>  		b="\${__git_ps1_branch_name}"
> diff --git a/t/t9903-bash-prompt.sh b/t/t9903-bash-prompt.sh
> index bbd513bab0..abd82eec35 100755
> --- a/t/t9903-bash-prompt.sh
> +++ b/t/t9903-bash-prompt.sh
> @@ -541,7 +541,7 @@ test_expect_success 'prompt - pc mode' '
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - branch name' '
> -	printf "BEFORE: (${c_green}\${__git_ps1_branch_name}${c_clear}):AFTER\\nmain" >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name}):AFTER\\n${c_green}main${c_clear}" >expected &&
>  	(
>  		GIT_PS1_SHOWCOLORHINTS=y &&
>  		__git_ps1 "BEFORE:" ":AFTER" >"$actual" &&
> @@ -551,7 +551,7 @@ test_expect_success 'prompt - bash color pc mode - branch name' '
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - detached head' '
> -	printf "BEFORE: (${c_red}\${__git_ps1_branch_name}${c_clear}):AFTER\\n(%s...)" $(git log -1 --format="%h" b1^) >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name}):AFTER\\n${c_red}(%s...)"${c_clear} $(git log -1 --format="%h" b1^) >expected &&
>  	git checkout b1^ &&
>  	test_when_finished "git checkout main" &&
>  	(
> @@ -563,7 +563,7 @@ test_expect_success 'prompt - bash color pc mode - detached head' '
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - dirty status indicator - dirty worktree' '
> -	printf "BEFORE: (${c_green}\${__git_ps1_branch_name}${c_clear} ${c_red}*${c_clear}):AFTER\\nmain" >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name} ${c_red}*${c_clear}):AFTER\\n${c_green}main${c_clear}" >expected &&
>  	echo "dirty" >file &&
>  	test_when_finished "git reset --hard" &&
>  	(
> @@ -576,7 +576,7 @@ test_expect_success 'prompt - bash color pc mode - dirty status indicator - dirt
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - dirty status indicator - dirty index' '
> -	printf "BEFORE: (${c_green}\${__git_ps1_branch_name}${c_clear} ${c_green}+${c_clear}):AFTER\\nmain" >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name} ${c_green}+${c_clear}):AFTER\\n${c_green}main${c_clear}" >expected &&
>  	echo "dirty" >file &&
>  	test_when_finished "git reset --hard" &&
>  	git add -u &&
> @@ -590,7 +590,7 @@ test_expect_success 'prompt - bash color pc mode - dirty status indicator - dirt
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - dirty status indicator - dirty index and worktree' '
> -	printf "BEFORE: (${c_green}\${__git_ps1_branch_name}${c_clear} ${c_red}*${c_green}+${c_clear}):AFTER\\nmain" >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name} ${c_red}*${c_clear}${c_green}+${c_clear}):AFTER\\n${c_green}main${c_clear}" >expected &&
>  	echo "dirty index" >file &&
>  	test_when_finished "git reset --hard" &&
>  	git add -u &&
> @@ -605,7 +605,7 @@ test_expect_success 'prompt - bash color pc mode - dirty status indicator - dirt
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - dirty status indicator - before root commit' '
> -	printf "BEFORE: (${c_green}\${__git_ps1_branch_name}${c_clear} ${c_green}#${c_clear}):AFTER\\nmain" >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name} ${c_green}#${c_clear}):AFTER\\n${c_green}main${c_clear}" >expected &&
>  	(
>  		GIT_PS1_SHOWDIRTYSTATE=y &&
>  		GIT_PS1_SHOWCOLORHINTS=y &&
> @@ -617,7 +617,7 @@ test_expect_success 'prompt - bash color pc mode - dirty status indicator - befo
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - inside .git directory' '
> -	printf "BEFORE: (${c_green}\${__git_ps1_branch_name}${c_clear}):AFTER\\nGIT_DIR!" >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name}):AFTER\\n${c_green}GIT_DIR!${c_clear}" >expected &&
>  	echo "dirty" >file &&
>  	test_when_finished "git reset --hard" &&
>  	(
> @@ -631,7 +631,7 @@ test_expect_success 'prompt - bash color pc mode - inside .git directory' '
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - stash status indicator' '
> -	printf "BEFORE: (${c_green}\${__git_ps1_branch_name}${c_clear} ${c_lblue}\$${c_clear}):AFTER\\nmain" >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name} ${c_lblue}\$${c_clear}):AFTER\\n${c_green}main${c_clear}" >expected &&
>  	echo 2 >file &&
>  	git stash &&
>  	test_when_finished "git stash drop" &&
> @@ -645,7 +645,7 @@ test_expect_success 'prompt - bash color pc mode - stash status indicator' '
>  '
>  
>  test_expect_success 'prompt - bash color pc mode - untracked files status indicator' '
> -	printf "BEFORE: (${c_green}\${__git_ps1_branch_name}${c_clear} ${c_red}%%${c_clear}):AFTER\\nmain" >expected &&
> +	printf "BEFORE: (\${__git_ps1_branch_name} ${c_red}%%${c_clear}):AFTER\\n${c_green}main${c_clear}" >expected &&
>  	(
>  		GIT_PS1_SHOWUNTRACKEDFILES=y &&
>  		GIT_PS1_SHOWCOLORHINTS=y &&
> -- 
> 2.36.1
>