lib-sieve: util: rfc2822: Added rfc2822_header_write_address() which allows...

lib-sieve: util: rfc2822: Added rfc2822_header_write_address() which allows adding a header with one or more addresses.

It applies UTF8 encoding only when the address string somehow contains 8-bit characters.
Sieve addresses are supposed to have any UTF8 characters in the phase MIME-encoded, not literal 8-bit characters.
However, this has been allowed from the beginning, so disabling the old behavior may break existing installations.
This function allows supporting both options.

src/lib-sieve/util/rfc2822.c

@@ -242,3 +242,23 @@ void rfc2822_header_utf8_printf
 	rfc2822_header_write(header, name, str_c(body));
 }
 
+
+void rfc2822_header_write_address(string_t *header,
+	const char *name, const char *address)
+{
+	bool has_8bit = FALSE;
+	const char *p;
+
+	for (p = address; *p != '\0'; p++) {
+		if ((*p & 0x80) != 0)
+			has_8bit = TRUE;
+	}
+
+	if (!has_8bit) {
+		rfc2822_header_write(header, name, address);
+	} else {
+		string_t *body = t_str_new(256);
+		message_header_encode(address, body);
+		rfc2822_header_write(header, name, str_c(body));
+	}
+}

src/lib-sieve/util/rfc2822.h

@@ -42,4 +42,8 @@ void rfc2822_header_printf
 void rfc2822_header_utf8_printf
 	(string_t *header, const char *name, const char *fmt, ...) ATTR_FORMAT(3, 4);
 
+void rfc2822_header_write_address(string_t *header,
+	const char *name, const char *address);
+
+
 #endif /* __RFC2822_H */