format-patch: add --no-cc, --no-to, and --no-add-headers

These new options allow users to override their config settings for
format.cc, format.to and format.headers respectively. These options
only make git ignore the config settings and any previous command line
options, so you'll still have to add more command line options to add
extra headers. For example,

	$ cat .git/config
	[format]
		to = Someone <someone@out.there>
	$ git format-patch -1 --no-to --to="Someone Else <else@out.there>"

would format a patch addressed to "Someone Else" and not "Someone".

Signed-off-by: Stephen Boyd <bebarino@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin-log.c

@@ -869,19 +869,31 @@ static int inline_callback(const struct option *opt, const char *arg, int unset)
 
 static int header_callback(const struct option *opt, const char *arg, int unset)
 {
-	add_header(arg);
+	if (unset) {
+		string_list_clear(&extra_hdr, 0);
+		string_list_clear(&extra_to, 0);
+		string_list_clear(&extra_cc, 0);
+	} else {
+	    add_header(arg);
+	}
 	return 0;
 }
 
 static int to_callback(const struct option *opt, const char *arg, int unset)
 {
-	string_list_append(arg, &extra_to);
+	if (unset)
+		string_list_clear(&extra_to, 0);
+	else
+		string_list_append(arg, &extra_to);
 	return 0;
 }
 
 static int cc_callback(const struct option *opt, const char *arg, int unset)
 {
-	string_list_append(arg, &extra_cc);
+	if (unset)
+		string_list_clear(&extra_cc, 0);
+	else
+		string_list_append(arg, &extra_cc);
 	return 0;
 }
 
@@ -940,12 +952,11 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		  PARSE_OPT_NONEG | PARSE_OPT_NOARG },
 		OPT_GROUP("Messaging"),
 		{ OPTION_CALLBACK, 0, "add-header", NULL, "header",
-			    "add email header", PARSE_OPT_NONEG,
-			    header_callback },
+			    "add email header", 0, header_callback },
 		{ OPTION_CALLBACK, 0, "to", NULL, "email", "add To: header",
-			    PARSE_OPT_NONEG, to_callback },
+			    0, to_callback },
 		{ OPTION_CALLBACK, 0, "cc", NULL, "email", "add Cc: header",
-			    PARSE_OPT_NONEG, cc_callback },
+			    0, cc_callback },
 		OPT_STRING(0, "in-reply-to", &in_reply_to, "message-id",
 			    "make first mail a reply to <message-id>"),
 		{ OPTION_CALLBACK, 0, "attach", &rev, "boundary",

t/t4014-format-patch.sh

@@ -157,6 +157,44 @@ test_expect_success 'configuration To: header' '
 	grep "^To: R. E. Cipient <rcipient@example.com>\$" patch9
 '
 
+test_expect_success '--no-to overrides config.to' '
+
+	git config --replace-all format.to \
+		"R. E. Cipient <rcipient@example.com>" &&
+	git format-patch --no-to --stdout master..side |
+	sed -e "/^\$/q" >patch10 &&
+	! grep "^To: R. E. Cipient <rcipient@example.com>\$" patch10
+'
+
+test_expect_success '--no-to and --to replaces config.to' '
+
+	git config --replace-all format.to \
+		"Someone <someone@out.there>" &&
+	git format-patch --no-to --to="Someone Else <else@out.there>" \
+		--stdout master..side |
+	sed -e "/^\$/q" >patch11 &&
+	! grep "^To: Someone <someone@out.there>\$" patch11 &&
+	grep "^To: Someone Else <else@out.there>\$" patch11
+'
+
+test_expect_success '--no-cc overrides config.cc' '
+
+	git config --replace-all format.cc \
+		"C. E. Cipient <rcipient@example.com>" &&
+	git format-patch --no-cc --stdout master..side |
+	sed -e "/^\$/q" >patch12 &&
+	! grep "^Cc: C. E. Cipient <rcipient@example.com>\$" patch12
+'
+
+test_expect_success '--no-add-headers overrides config.headers' '
+
+	git config --replace-all format.headers \
+		"Header1: B. E. Cipient <rcipient@example.com>" &&
+	git format-patch --no-add-headers --stdout master..side |
+	sed -e "/^\$/q" >patch13 &&
+	! grep "^Header1: B. E. Cipient <rcipient@example.com>\$" patch13
+'
+
 test_expect_success 'multiple files' '
 
 	rm -rf patches/ &&