Re: [BUG] Regression in 'git mergetool --tool-help'

From: Philippe Blain <levraiphilippeblain@gmail.com>
Date: Dec 20, 2020, 02:13 UTC
Message-ID: <c4f2330f-715b-1745-5ad7-5477f4e833db@gmail.com>
In-Reply-To: <xmqqsg81pvm8.fsf@gitster.c.googlers.com>

Hi Junio, Hi Felipe,

Le 2020-12-19 à 12:13, Junio C Hamano a écrit :

Show 20 quoted lines

> Felipe Contreras <felipe.contreras@gmail.com> writes:
> 
>> Junio C Hamano wrote:
>>> Felipe Contreras <felipe.contreras@gmail.com> writes:
>>>> How about this?
>>>>
>>>> --- a/git-mergetool--lib.sh
>>>> +++ b/git-mergetool--lib.sh
>>>> @@ -46,7 +46,7 @@ show_tool_names () {
>>>>                  while read scriptname
>>>>                  do
>>>>                          setup_tool "$scriptname" 2>/dev/null
>>>> -                       variants="$variants$(list_tool_variants)\n"
>>>> +                       variants="$variants$(list_tool_variants)"$'\n'
>>>>                  done
>>>>                  variants="$(echo "$variants" | sort | uniq)"
>>>
>>> Ah, I didn't see your variant before sending mine.  $'\n' would work
>>> with bash but we prefer not to rely on bashisms here.
>>

Thanks for both answers. Felipe's solution does the trick, but Junio's does not; it seems we do have to have a newline there. The following also works, and I think is portable:

diff --git i/git-mergetool--lib.sh w/git-mergetool--lib.sh
index 2defef28cd..6f03975493 100644
--- i/git-mergetool--lib.sh
+++ w/git-mergetool--lib.sh
@@ -46,7 +46,7 @@ show_tool_names () {
  		while read scriptname
  		do
  			setup_tool "$scriptname" 2>/dev/null
-			variants="$variants$(list_tool_variants)\n"
+			variants="$(echo "$variants" && list_tool_variants)"
  		done
  		variants="$(echo "$variants" | sort | uniq)"

I figured out what was different between the different Ubuntu versions I was testing:
the Ubuntu 14 and 18 systems have Bash as /bin/sh, but my Ubuntu 20 system
has /usr/bin/dash as /bin/sh (the default for Ubuntu these days).

I'll try to send a formal patch with the diff above, time permitting...

Also of note: I was wondering why 'araxis' was showing up in the list of available tools,
as Araxis Merge is macOS and Windows only (!). Turns out that the imagemagick package installs
a /usr/bin/compare symlink to /usr/bin/compare-im6.q16, so since Araxis merge is registered in
mergetools/araxis::translate_merge_tool_path as 'compare', it ends up in the list of available
merge tools... I think we could do better here but I'm not sure how.

Cheers,

Philippe.