Re: [PATCH v3 1/4] completion: be nicer with zsh

[Jonathan Nieder <jrnieder@gmail.com>]

Hi,

Felipe Contreras wrote:

> Felipe Contreras (4):
>   completion: be nicer with zsh

Since I can't find this patch in the mail archive, I'll reply here.
Luckily the most important bit is above already.

I think I mentioned before that this subject line is what will appear
in the shortlog and the shortlog is all that some people will see of
the changelog, so it should include a self-contained description of
the impact of the patch.

However, clearly I did not say it clearly enough. :)  I guess it's
better to take a cue from storytellers and show rather than tell.
(Please don't take this as a precedent --- I will not always be doing
the style fixes myself, and sometimes will consider a patch to scratch
someone else's itch not worth the trouble and work on something else.)

-- >8 --
From: Felipe Contreras <felipe.contreras@gmail.com>
Date: Thu, 2 Feb 2012 03:15:17 +0200
Subject: completion: avoid default value assignment on : true command

zsh versions from 4.3.0 to present (4.3.15) do not correctly propagate
the SH_WORD_SPLIT option into the subshell in ${foo:=$(bar)}
expressions.  For example, after running

	emulate sh
	fn () {
		var='one two'
		printf '%s\n' $var
	}
	x=$(fn)
	: ${y=$(fn)}

printing "$x" results in two lines as expected, but printing "$y"
results in a single line because $var is expanded as a single word
when evaluating fn to compute y.

So avoid the construct, and use an explicit 'test -n "$foo" ||
foo=$(bar)' instead.  This fixes a bug tht caused all commands to be
treated as porcelain and show up in "git <TAB><TAB>" completion,
because the list of all commands was treated as a single word in
__git_list_porcelain_commands and did not match any of the patterns
that would usually cause plumbing to be excluded.

[jn: clarified commit message, indentation style fix]

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
---
 contrib/completion/git-completion.bash |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/contrib/completion/git-completion.bash b/contrib/completion/git-completion.bash
index 78be1958..d7965daf 100755
--- a/contrib/completion/git-completion.bash
+++ b/contrib/completion/git-completion.bash
@@ -676,7 +676,8 @@ __git_merge_strategies=
 # is needed.
 __git_compute_merge_strategies ()
 {
-	: ${__git_merge_strategies:=$(__git_list_merge_strategies)}
+	[ -n "$__git_merge_strategies" ] ||
+	__git_merge_strategies=$(__git_list_merge_strategies)
 }
 
 __git_complete_revlist_file ()
@@ -854,7 +855,8 @@ __git_list_all_commands ()
 __git_all_commands=
 __git_compute_all_commands ()
 {
-	: ${__git_all_commands:=$(__git_list_all_commands)}
+	[ -n "$__git_all_commands" ] ||
+	__git_all_commands=$(__git_list_all_commands)
 }
 
 __git_list_porcelain_commands ()
@@ -947,7 +949,8 @@ __git_porcelain_commands=
 __git_compute_porcelain_commands ()
 {
 	__git_compute_all_commands
-	: ${__git_porcelain_commands:=$(__git_list_porcelain_commands)}
+	[ -n "$__git_porcelain_commands" ] ||
+	__git_porcelain_commands=$(__git_list_porcelain_commands)
 }
 
 __git_pretty_aliases ()
-- 
1.7.9