[PATCH] aiaiai-email-lda: use the References mail header

[Artem Bityutskiy]

On Thu, 2014-11-06 at 19:50 +0100, Robert Jarzmik wrote:
> Aiaiai local mail delivery agent should be able to cope with forwarded
> mails, not only git-send-email.
> 
> One popular method of forwarding a mail thread is to have it embedded in
> a single mulitpart mail in rfc822 format. But this transformation
> changes the In-Reply-To: headers into References: headers.
> 
> The goal of this patch is to teach aiaiai LDA to understand both
> In-Reply-To and References in its mail handling. This enables mail
> forwarding.
> 
> Signed-off-by: Robert Jarzmik <robert.jarzmik at free.fr>
> ---
>  doc/README             | 22 ++++++++++++++++++++++
>  email/aiaiai-email-lda | 13 ++++++++-----
>  2 files changed, 30 insertions(+), 5 deletions(-)
> 
> diff --git a/doc/README b/doc/README
> index 0e699a2..0e6571c 100644
> --- a/doc/README
> +++ b/doc/README
> @@ -102,6 +102,28 @@ The 'aiaiai-test-patchset' script does all the testing work and outputs the
>  test results to stdout. 'aiaiai-email-test-patchset' captures the output and
>  sends it back to the patch submitter.
>  
> +A more complicated mail setup dealing with forwards and multi-part emails
> +would be :
> +$ cat /home/aiaiai/bin/my-aiaiai-lda
> +	#!/bin/sh
> +	formail_opt=""

Thanks. But would you please quote variables. This is the convention we
follow in this set of scripts, for our on good.

> +	mail=$(mktemp)

"$(mktemp)"

> +	cat > $mail

"$mail"

> +	to="$(formail -c -z -x "To:" < $mail)"

"$mail"

> +	[ -n "$to" ] && formail_opt="$formail_opt -I \"To: $to\""
> +
> +	project="$(formail -c -z -x "X-Aiaiai-Project:" < $mail)"

"$mail"

> +	[ -n "$project" ] && formail_opt="$formail_opt -I \"X-Aiaiai-Project: $project\""
> +
> +	commit="$(formail -c -z -x "X-Aiaiai-Commit:" < $mail)"

"$mail"

> +	[ -n "$commit" ] && formail_opt="$formail_opt -I \"X-Aiaiai-Commit: $commit\""
> +
> +	cat "$mail" | eval formail $formail_opt -d -s $HOME/git/email/aiaiai-email-lda \
> +	-v --reap-archive=43200 --reap-incomplete=10 -- $HOME/aiaiai-workdir \
> +	>> $HOME/aiaiai-logs/email-lda.log" 2>&1

The last quote has no beginning?

How about this:

cat "$mail" | eval formail "$(formail_opt -d -s
"$HOME/git/email/aiaiai-email-lda" v --reap-archive=43200
--reap-incomplete=10 -- "$HOME/aiaiai-workdir")" >>
"$HOME/aiaiai-logs/email-lda.log"

(not tested)

Yes, this is sound a bit of "too much". But the thing is that shell is a
very weird language, and big shell scripts are usually completely
unreadable and unmaintainable.

Today I'd choose python to write this stuff. Bat back to that time I did
not know python :-)

Anyway, aiaiai is has a lot of shell code. To make it more readable,
robust, and maintainable, we try to follow strict rules. One of them -
always quote variables.

Unquoted variables are dangerous - if it has a white-space, the program
falls apart. Also, if it is empty, it has different semantics comparing
to a quoted one (nothing vs empty line).

So we quote everything. Except the cases where we deliberately don't do
this. Like: program $verbose

We know that verbose is either -v or nothing. So "program" will either
be called with -v or no argument. If we quoted it, then instead of no
argument, the program would be called with an empty argument, which is a
different thing.

In your case, you call mktemp. You can rely on the fact that it will
return a shell-friendly name, yes. But I ask to quote just for the
consistency.

Thanks!