Re: git-prompt.sh vs leading white space in __git_ps1()::printf_format

[Junio C Hamano <gitster@pobox.com>]

Simon Oosthoek <s.oosthoek@xs4all.nl> writes:

> On 12/12/12 18:50, Junio C Hamano wrote:
>> Simon Oosthoek <s.oosthoek@xs4all.nl> writes:
>> 
>>> This removes most of the ambiguities :-)
>>> Ack from me!
>> 
>> OK, as this is a low-impact finishing touch for a new feature, I'll
>> fast-track this to 'master' before the final release.
>> 
>
> Ok, wonderful!
> BTW, I tried the thing I mentioned and it was safe to do:
> PS1='blabla$(__git_ps1 x y)blabla'
> will not eat your prompt, although I'd recommend putting something
> useful instead of blabla ;-)

Actually, I deeply regret merging this to 'master'.  The original
"as a command substitution in PS1" mode, you could add anything
around the status string, so I could do:

	PS1=': \h \W$(__git_ps1 "/%s"); '

to get something like:

	: hostname dirname/<STATUS>; <CURSOR HERE>

In the new PROMPT_COMMAND mode, there is always parentheses around
the status string (and an SP before the parenthesees) that the user
cannot get rid of.

This is not a usability regression per-se (if you do not like the
extra parentheses, you do not have to use the colored mode), but is
something that will make me never use the mode.

Can we make it take an optional third parameter so that we could say

	PROMPT_COMMAND='__git_ps1 ": \h \W" "; " "/%s"'

to do the same as what the command substitution mode would have
given for

	PS1=': \h \W$(__git_ps1 "/%s"); '

perhaps?

Totally untested, but perhaps along this line.

 contrib/completion/git-prompt.sh | 24 ++++++++++++++----------
 1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
index 9b074e1..b2579f4 100644
--- a/contrib/completion/git-prompt.sh
+++ b/contrib/completion/git-prompt.sh
@@ -236,9 +236,10 @@ __git_ps1 ()
 	local printf_format=' (%s)'
 
 	case "$#" in
-		2)	pcmode=yes
+		2|3)	pcmode=yes
 			ps1pc_start="$1"
 			ps1pc_end="$2"
+			printf_format="${3:-$printf_format}"
 		;;
 		0|1)	printf_format="${1:-$printf_format}"
 		;;
@@ -339,6 +340,7 @@ __git_ps1 ()
 
 		local f="$w$i$s$u"
 		if [ $pcmode = yes ]; then
+			local ps1=
 			if [ -n "${GIT_PS1_SHOWCOLORHINTS-}" ]; then
 				local c_red='\e[31m'
 				local c_green='\e[32m'
@@ -356,29 +358,31 @@ __git_ps1 ()
 					branch_color="$bad_color"
 				fi
 
-				# Setting PS1 directly with \[ and \] around colors
+				# Setting ps1 directly with \[ and \] around colors
 				# is necessary to prevent wrapping issues!
-				PS1="$ps1pc_start (\[$branch_color\]$branchstring\[$c_clear\]"
+				ps1="\[$branch_color\]$branchstring\[$c_clear\]"
 
 				if [ -n "$w$i$s$u$r$p" ]; then
-					PS1="$PS1 "
+					ps1="$ps1 "					
 				fi
 				if [ "$w" = "*" ]; then
-					PS1="$PS1\[$bad_color\]$w"
+					ps1="$ps1\[$bad_color\]$w"
 				fi
 				if [ -n "$i" ]; then
-					PS1="$PS1\[$ok_color\]$i"
+					ps1="$ps1\[$ok_color\]$i"
 				fi
 				if [ -n "$s" ]; then
-					PS1="$PS1\[$flags_color\]$s"
+					ps1="$ps1\[$flags_color\]$s"
 				fi
 				if [ -n "$u" ]; then
-					PS1="$PS1\[$bad_color\]$u"
+					ps1="$ps1\[$bad_color\]$u"
 				fi
-				PS1="$PS1\[$c_clear\]$r$p)$ps1pc_end"
+				ps1="$ps1\[$c_clear\]$r$p"
 			else
-				PS1="$ps1pc_start ($c${b##refs/heads/}${f:+ $f}$r$p)$ps1pc_end"
+				ps1="$c${b##refs/heads/}${f:+ $f}$r$p"
 			fi
+			ps1=$(printf -- "$printf_format" "$ps1")
+			PS1="$ps1pc_start$ps1$ps1pc_end"
 		else
 			# NO color option unless in PROMPT_COMMAND mode
 			printf -- "$printf_format" "$c${b##refs/heads/}${f:+ $f}$r$p"