git-send-email: introduce compose-encoding

The introduction email (--compose option) have encoding hardcoded to
UTF-8, but invoked editor may not use UTF-8 encoding.
The encoding used by patches can be changed by the "8bit-encoding"
option, but this option does not have effect on introduction email
and equivalent for introduction email is missing.

Added compose-encoding command line option and sendemail.composeencoding
configuration option specify encoding of introduction email.

Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-send-email.txt

@@ -126,6 +126,10 @@ The --to option must be repeated for each user you want on the to list.
 +
 Note that no attempts whatsoever are made to validate the encoding.
 
+--compose-encoding=<encoding>::
+	Specify encoding of compose message. Default is the value of the
+	'sendemail.composeencoding'; if that is unspecified, UTF-8 is assumed.
+
 
 Sending
 ~~~~~~~

git-send-email.perl

@@ -56,6 +56,7 @@ sub usage {
     --in-reply-to           <str>  * Email "In-Reply-To:"
     --annotate                     * Review each patch that will be sent in an editor.
     --compose                      * Open an editor for introduction.
+    --compose-encoding      <str>  * Encoding to assume for introduction.
     --8bit-encoding         <str>  * Encoding to assume 8bit mails if undeclared
 
   Sending:
@@ -198,6 +199,7 @@ sub do_edit {
 my ($validate, $confirm);
 my (@suppress_cc);
 my ($auto_8bit_encoding);
+my ($compose_encoding);
 
 my ($debug_net_smtp) = 0;		# Net::SMTP, see send_message()
 
@@ -231,6 +233,7 @@ sub do_edit {
     "confirm"   => \$confirm,
     "from" => \$sender,
     "assume8bitencoding" => \$auto_8bit_encoding,
+    "composeencoding" => \$compose_encoding,
 );
 
 my %config_path_settings = (
@@ -315,6 +318,7 @@ sub signal_handler {
 		    "validate!" => \$validate,
 		    "format-patch!" => \$format_patch,
 		    "8bit-encoding=s" => \$auto_8bit_encoding,
+		    "compose-encoding=s" => \$compose_encoding,
 		    "force" => \$force,
 	 );
 
@@ -638,10 +642,13 @@ sub get_patch_subject {
 			$summary_empty = 0 unless (/^\n$/);
 		} elsif (/^\n$/) {
 			$in_body = 1;
+			if (!defined $compose_encoding) {
+				$compose_encoding = "UTF-8";
+			}
 			if ($need_8bit_cte) {
 				print $c2 "MIME-Version: 1.0\n",
 					 "Content-Type: text/plain; ",
-					   "charset=UTF-8\n",
+					   "charset=$compose_encoding\n",
 					 "Content-Transfer-Encoding: 8bit\n";
 			}
 		} elsif (/^MIME-Version:/i) {

t/t9001-send-email.sh

@@ -854,6 +854,61 @@ test_expect_success $PREREQ 'utf8 author is correctly passed on' '
 	grep "^From: Füñný Nâmé <odd_?=mail@example.com>" msgtxt1
 '
 
+test_expect_success $PREREQ 'sendemail.composeencoding works' '
+	clean_fake_sendmail &&
+	git config sendemail.composeencoding iso-8859-1 &&
+	(echo "#!$SHELL_PATH" &&
+	 echo "echo utf8 body: àéìöú >>\"\$1\""
+	) >fake-editor-utf8 &&
+	chmod +x fake-editor-utf8 &&
+	  GIT_EDITOR="\"$(pwd)/fake-editor-utf8\"" \
+	  git send-email \
+	  --compose --subject foo \
+	  --from="Example <nobody@example.com>" \
+	  --to=nobody@example.com \
+	  --smtp-server="$(pwd)/fake.sendmail" \
+	  $patches &&
+	grep "^utf8 body" msgtxt1 &&
+	grep "^Content-Type: text/plain; charset=iso-8859-1" msgtxt1
+'
+
+test_expect_success $PREREQ '--compose-encoding works' '
+	clean_fake_sendmail &&
+	(echo "#!$SHELL_PATH" &&
+	 echo "echo utf8 body: àéìöú >>\"\$1\""
+	) >fake-editor-utf8 &&
+	chmod +x fake-editor-utf8 &&
+	  GIT_EDITOR="\"$(pwd)/fake-editor-utf8\"" \
+	  git send-email \
+	  --compose-encoding iso-8859-1 \
+	  --compose --subject foo \
+	  --from="Example <nobody@example.com>" \
+	  --to=nobody@example.com \
+	  --smtp-server="$(pwd)/fake.sendmail" \
+	  $patches &&
+	grep "^utf8 body" msgtxt1 &&
+	grep "^Content-Type: text/plain; charset=iso-8859-1" msgtxt1
+'
+
+test_expect_success $PREREQ '--compose-encoding overrides sendemail.composeencoding' '
+	clean_fake_sendmail &&
+	git config sendemail.composeencoding iso-8859-1 &&
+	(echo "#!$SHELL_PATH" &&
+	 echo "echo utf8 body: àéìöú >>\"\$1\""
+	) >fake-editor-utf8 &&
+	chmod +x fake-editor-utf8 &&
+	  GIT_EDITOR="\"$(pwd)/fake-editor-utf8\"" \
+	  git send-email \
+	  --compose-encoding iso-8859-2 \
+	  --compose --subject foo \
+	  --from="Example <nobody@example.com>" \
+	  --to=nobody@example.com \
+	  --smtp-server="$(pwd)/fake.sendmail" \
+	  $patches &&
+	grep "^utf8 body" msgtxt1 &&
+	grep "^Content-Type: text/plain; charset=iso-8859-2" msgtxt1
+'
+
 test_expect_success $PREREQ 'detects ambiguous reference/file conflict' '
 	echo master > master &&
 	git add master &&