v2tg-create.sh: Support for multiple {to,cc,bcc} options

> Git config supports multiple values for the same config key, so support it
> for these TopGit config options, too.
> 
> New in v2:
> Print a RFC2822 compliant header.
> 
> Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>

> ---
>  tg-create.sh |   35 ++++++++++++++++++++++++++++++++---
>  1 files changed, 32 insertions(+), 3 deletions(-)
> 
> diff --git a/tg-create.sh b/tg-create.sh
> index 6cce7ed..d7ee1d2 100644
> --- a/tg-create.sh
> +++ b/tg-create.sh
> @@ -100,13 +100,42 @@ git checkout -b "$name"
>  echo "$deps" | sed 's/ /\n/g' >"$root_dir/.topdeps"
>  git add "$root_dir/.topdeps"
>  
> +# Print a RFC2822 compliant header ($2) with values from the config option
> +# ($1 without the topgit. prefix)
> +get_multi_config()
> +{
> +	# Do we need to escape it for awk double quotes?
> +	prefix="$2"
> +	prefix_align="$(printf "%*s  " "${#2}" "")"
> +
> +	git config --get-all topgit.$1 |
> +		awk '
> +			BEGIN {
> +				line = ""
> +				prefix = "'"$prefix"': "
> +			}
> +				{
> +					if (line != "") {
> +						print prefix line ","
> +						prefix = "'"$prefix_align"'"
> +					}
> +					line = $0
> +				}
> +			END {
> +				if (line != "") {
> +					print prefix line
> +				}
> +			}
> +		'
> +}
> +

>  author="$(git var GIT_AUTHOR_IDENT)"
>  author_addr="${author%> *}>"
>  {
>  	echo "From: $author_addr"
> -	! header="$(git config topgit.to)" || echo "To: $header"
> -	! header="$(git config topgit.cc)" || echo "Cc: $header"
> -	! header="$(git config topgit.bcc)" || echo "Bcc: $header"
> +	get_multi_config to  "To"
> +	get_multi_config cc  "Cc"
> +	get_multi_config bcc "Bcc"
>  	! subject_prefix="$(git config topgit.subjectprefix)" || subject_prefix="$subject_prefix "
>  	echo "Subject: [${subject_prefix}PATCH] $name"
>  	echo
> -- 
> tg: (2e5b885..) t/support-for-multiple-to-cc-bcc-options (depends on: master)

>  Hi,
>
> On Sat, Aug 09, 2008 at 08:48:56PM +0200, Bert Wesarg wrote:
>> Git config supports multiple values for the same config key, so support it
>> for these TopGit config options, too.
>>
>> New in v2:
>> Print a RFC2822 compliant header.
>>
>> Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
>
>  oops, I'm really sorry! I thought I already commented on this while
> apparently, I forgot to.
>
>> ---
>>  tg-create.sh |   35 ++++++++++++++++++++++++++++++++---
>>  1 files changed, 32 insertions(+), 3 deletions(-)
>>
>> diff --git a/tg-create.sh b/tg-create.sh
>> index 6cce7ed..d7ee1d2 100644
>> --- a/tg-create.sh
>> +++ b/tg-create.sh
>> @@ -100,13 +100,42 @@ git checkout -b "$name"
>>  echo "$deps" | sed 's/ /\n/g' >"$root_dir/.topdeps"
>>  git add "$root_dir/.topdeps"
>>
>> +# Print a RFC2822 compliant header ($2) with values from the config option
>> +# ($1 without the topgit. prefix)
>> +get_multi_config()
>> +{
>> +     # Do we need to escape it for awk double quotes?
>> +     prefix="$2"
>> +     prefix_align="$(printf "%*s  " "${#2}" "")"
>> +
>> +     git config --get-all topgit.$1 |
>> +             awk '
>> +                     BEGIN {
>> +                             line = ""
>> +                             prefix = "'"$prefix"': "
>> +                     }
>> +                             {
>> +                                     if (line != "") {
>> +                                             print prefix line ","
>> +                                             prefix = "'"$prefix_align"'"
>> +                                     }
>> +                                     line = $0
>> +                             }
>> +                     END {
>> +                             if (line != "") {
>> +                                     print prefix line
>> +                             }
>> +                     }
>> +             '
>> +}
>> +
>
> I'm not too happy about this, for several reasons:
>
>        (i) This code is so awfully complicated.

>
>        (ii) It would be simpler to just prefix all the further lines
> with a tab; wouldn't something like
>
>                sed '2,$s/^/\t/'

>
> actually work?
>
>        (iii) This is troublesome because now header values can span
> multiple lines. Until now, we were just blisfully ignorant about this
> possibility. At least tg export needs to be adjusted to account for this
> now, and I fear dealing with this will be pretty annoying when
> prototyping new features.