Re: [PATCH v2] git-gui: remove lines starting with the comment character

From: Eric Sunshine <sunshine@sunshineco.com>
Date: Feb 28, 2021, 23:00 UTC
Message-ID: <CAPig+cT-sfgMDi9-6AEKF85NtOiXeqddJjk-pYuhDtTVAE-UEw@mail.gmail.com>
In-Reply-To: <20210218181937.83419-1-me@yadavpratyush.com>

[Junio: please do not pull the latest git-gui changes yet; they break on macOS, making git-gui unusable]

On Thu, Feb 18, 2021 at 1:20 PM Pratyush Yadav <me@yadavpratyush.com> wrote:

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> The comment character is specified by the config variable
> 'core.commentchar'. Any lines starting with this character is considered
> a comment and should not be included in the final commit message.
>
> Teach git-gui to filter out lines in the commit message that start with
> the comment character using git-stripspace. If the config is not set,
> '#' is taken as the default. Also add a message educating users about
> the comment character.

Thanks for working on this. I've been looking forward to the improvement; the old behavior of not stripping comment lines has been a long-time annoyance.

Unfortunately, however, the changes break git-gui badly on macOS. See below...

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> Signed-off-by: Pratyush Yadav <me@yadavpratyush.com>
> ---
> diff --git a/git-gui.sh b/git-gui.sh
> @@ -3436,6 +3437,10 @@ proc trace_commit_type {varname args} {
> +       set comment_char [get_config core.commentchar]
> +       set txt [string cat $txt \
> +                                [mc " (Lines starting with '$comment_char' will be ignored)"]]

The old Tcl 8.5.9 on macOS does not have a string `cat` method, so `string cat` crashes:

    can't set "commit_type": unknown or ambiguous subcommand "cat":
        must be bytelength, compare, equal, first, index, is, last,
        length, map, match, range, repeat, replace, reverse, tolower,
        totitle, toupper, trim, trimleft, trimright, wordend, or
        wordstart
    unknown or ambiguous subcommand "cat": must be bytelength,
        compare, equal, first, index, is, last, length, map, match,
        range, repeat, replace, reverse, tolower, totitle, toupper,
        trim, trimleft, trimright, wordend, or wordstart while
        executing
    "string cat $txt [mc " (Lines starting with '$comment_char' will
        be ignored)"]"

Show 13 quoted lines

> diff --git a/lib/commit.tcl b/lib/commit.tcl
> @@ -141,6 +141,20 @@ proc setup_commit_encoding {msg_wt {quiet 0}} {
> +proc strip_msg {msg} {
> +       set cmd [concat [list | ] [_git_cmd stripspace] --strip-comments]
> +       _trace_exec $cmd
> +       set fd [open $cmd r+]
> +       fconfigure $fd -translation binary -encoding utf-8
> +       puts -nonewline $fd $msg
> +       close $fd w
> +       set result [read $fd]
> +       close $fd
> +       return $result
> +}

The old Tcl on macOS does not support closing one end of a bidirectional pipe, so `close $fd w` errors out:

    wrong # args: should be "close channelId"
    wrong # args: should be "close channelId"
        while executing
    "close $fd w"

I'll send a patch which resolves both problems.