return 0;
}
-static void add_rfc2047(struct strbuf *sb, const char *line, int len,
+static void add_rfc2047(struct strbuf *sb, const char *line, size_t len,
const char *encoding, enum rfc2047_type type)
{
static const int max_encoded_length = 76; /* per rfc2047 */
strbuf_grow(sb, len * 3 + strlen(encoding) + 100);
strbuf_addf(sb, "=?%s?q?", encoding);
line_len += strlen(encoding) + 5; /* 5 for =??q? */
- for (i = 0; i < len; i++) {
- unsigned ch = line[i] & 0xFF;
- int is_special = is_rfc2047_special(ch, type);
+
+ while (len) {
+ /*
+ * RFC 2047, section 5 (3):
+ *
+ * Each 'encoded-word' MUST represent an integral number of
+ * characters. A multi-octet character may not be split across
+ * adjacent 'encoded- word's.
+ */
+ const unsigned char *p = (const unsigned char *)line;
+ int chrlen = mbs_chrlen(&line, &len, encoding);
+ int is_special = (chrlen > 1) || is_rfc2047_special(*p, type);
+
+ /* "=%02X" * chrlen, or the byte itself */
+ const char *encoded_fmt = is_special ? "=%02X" : "%c";
+ int encoded_len = is_special ? 3 * chrlen : 1;
/*
* According to RFC 2047, we could encode the special character
* causes ' ' to be encoded as '=20', avoiding this problem.
*/
- if (line_len + 2 + (is_special ? 3 : 1) > max_encoded_length) {
+ if (line_len + encoded_len + 2 > max_encoded_length) {
+ /* It won't fit with trailing "?=" --- break the line */
strbuf_addf(sb, "?=\n =?%s?q?", encoding);
line_len = strlen(encoding) + 5 + 1; /* =??q? plus SP */
}
- if (is_special) {
- strbuf_addf(sb, "=%02X", ch);
- line_len += 3;
- } else {
- strbuf_addch(sb, ch);
- line_len++;
- }
+ for (i = 0; i < chrlen; i++)
+ strbuf_addf(sb, encoded_fmt, p[i]);
+ line_len += encoded_len;
}
strbuf_addstr(sb, "?=");
}