Re: [PATCH v2 2/2] mailinfo: unescape quoted-pair in header fields

> +static void unquote_quoted_string(struct strbuf *line)
> +{
> +	const char *in = strbuf_detach(line, NULL);
> +	int c, take_next_literally = 0;
> +	int found_error = 0;
> +
> +	/*
> +	 * Stores the character that started the escape mode so that we know what
> +	 * character will stop it
> +	 */
> +	char escape_context = 0;
> +
> +	while ((c = *in++) != 0) {
> +		if (take_next_literally) {
> +			take_next_literally = 0;
> +		} else {
> +			switch (c) {
> +			case '"':
> +				if (!escape_context)
> +					escape_context = '"';
> +				else if (escape_context == '"')
> +					escape_context = 0;
> +				continue;
> +			case '\\':
> +				if (escape_context) {
> +					take_next_literally = 1;
> +					continue;
> +				}
> +				break;
> +			case '(':
> +				if (!escape_context)
> +					escape_context = '(';
> +				break;
> +			case ')':
> +				if (escape_context == '(')
> +					escape_context = 0;
> +				break;
> +			}
> +		}
> +
> +		strbuf_addch(line, c);
> +	}
> +}