Re: [RFC] send-email: UTF-8 encoding in subject line

From: D. Ben Knoble <ben.knoble@gmail.com>
Date: Feb 22, 2026, 15:00 UTC
Message-ID: <CALnO6CBhB+O-CBCw3f+2n5yaHO7Wk7-Adaa9_4shXZvciGpUPA@mail.gmail.com>
In-Reply-To: <20260222140737.1760413-1-shreyanshpaliwalcmsmn@gmail.com>

On Sun, Feb 22, 2026 at 9:07 AM Shreyansh Paliwal <shreyanshpaliwalcmsmn@gmail.com> wrote:

Show 56 quoted lines

>
> > > That makes sense, I tried it below.
> > > I also wondered whether, in addition to this, it might be helpful to warn on
> > > an invalid charset, and/or possibly fall back to UTF-8.
> >
> > Agreed on the first half of the statement, if we have an easy and
> > portable way to tell if a given random string names a valid charset.
> > I do not recommend to "fall back" to anything, if we are asking an
> > input from the user.
>
> Following up on this, I tried adding a warning when the provided charset
> does not appear to be valid. Current flow is,
>
>   Which 8bit encoding should I declare [UTF-8]? y
>   Are you sure you want to use <y> [y/N]? y
>
> With the additional check, it becomes,
>
>   Which 8bit encoding should I declare [default: UTF-8]? y
>   warning: 'y' does not appear to be a valid charset name.
>   Are you sure you want to use <y> [y/N]?
>
> This uses find_encoding() from Perl’s Encode module to detect any
> unrecognized charset names.
>
> Let me know what you think.
> Also, is there any new test that should be added for this change?
>
> Signed-off-by: Shreyansh Paliwal <shreyanshpaliwalcmsmn@gmail.com>
> ---
>  git-send-email.perl | 23 ++++++++++++++++++++---
>  1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/git-send-email.perl b/git-send-email.perl
> index cd4b316ddc..e62fa259ba 100755
> --- a/git-send-email.perl
> +++ b/git-send-email.perl
> @@ -23,6 +23,7 @@
>  use Git::LoadCPAN::Error qw(:try);
>  use Git;
>  use Git::I18N;
> +use Encode qw(find_encoding);
>
>  Getopt::Long::Configure qw/ pass_through /;
>
> @@ -1044,9 +1045,25 @@ sub file_declares_8bit_cte {
>         foreach my $f (sort keys %broken_encoding) {
>                 print "    $f\n";
>         }
> -       $auto_8bit_encoding = ask(__("Which 8bit encoding should I declare [UTF-8]? "),
> -                                 valid_re => qr/.{4}/, confirm_only => 1,
> -                                 default => "UTF-8");
> +       while (1) {
> +               my $encoding = ask(__("Which 8bit encoding should I declare [default: UTF-8]? "),
> +                       valid_re => qr/^\S+$/,
> +                       default  => "UTF-8");

Here we change things, right?

- The original validation is "at least 4 characters", the new
validation is "at least one non-blank." I'm not sure why we'd prefer
one or the other, frankly. The original goes to 852a15d748
(send-email: ask confirmation if given encoding name is very short,
2015-02-13), which is motivated by the same problem we're discussing
here!
- We get rid of confirm_only, since we're about to roll our own
confirmation below:

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> +               next unless defined $encoding;
> +               if (find_encoding($encoding)) {
> +                       $auto_8bit_encoding = $encoding;
> +                       last;
> +               }
> +               printf STDERR __("warning: '%s' does not appear to be a valid charset name.\n"), $encoding;
> +               my $yesno = ask(
> +                       sprintf(__("Are you sure you want to use <%s> [y/N]? "), $encoding),
> +                       valid_re => qr/^(?:y|n)/i,
> +                       default  => 'n');

…which might want refactored a bit so it can stay close to the original? idk.

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> +               if (defined $yesno && $yesno =~ /^y/i) {
> +                       $auto_8bit_encoding = $encoding;
> +                       last;
> +               }
> +       }
>  }
>
>  if (!$force) {
> --
> 2.53.0

-- 
D. Ben Knoble