Function un_escape

ut.h:576–630

Un-escape URI user -- it takes a pointer to original user str, as well as the new, unescaped one, which MUST have an allocated buffer linked to the 'str' structure ; (the buffer can be allocated with the same length as the original string -- the output string is always shorter (if escaped characters occur) or same-long as the original one). only printable characters are perm

	unescaped string otherwise
*/
inline static int un_escape(str *user, str *new_user )
{
 	int i, j, value;
	int hi, lo;

	if( new_user==0 || new_user->s==0) {
		LM_CRIT("called with invalid param\n");
		return -1;
	}

	new_user->len = 0;
	j = 0;

	for (i = 0; i < user->len; i++) {
		if (user->s[i] == '%') {
			if (i + 2 >= user->len) {
				LM_ERR("escape sequence too short in"
					" '%.*s' @ %d\n",
					user->len, user->s, i );
				goto error;
			}
			hi=hex2int(user->s[i + 1]);
			if (hi<0) {
				LM_ERR(" non-hex high digit in an escape"
					" sequence in '%.*s' @ %d\n",
					user->len, user->s, i+1 );
				goto error;
			}
			lo=hex2int(user->s[i + 2]);
			if (lo<0) {
				LM_ERR("non-hex low digit in an escape sequence in "
					"'%.*s' @ %d\n",
					user->len, user->s, i+2 );
				goto error;
			}
			value=(hi<<4)+lo;
			if (value < 32 || value > 126) {
				LM_ERR("non-ASCII escaped character in '%.*s' @ %d\n",
					user->len, user->s, i );
				goto error;
			}
			new_user->s[j] = value;
			i+=2; /* consume the two hex digits, for cycle will move to the next char */
		} else {
			new_user->s[j] = user->s[i];
		}
        j++; /* good -- we translated another character */
	}
	new_user->len = j;
	return j;

error:
	new_user->len = j;
	return -1;
}

static inline void unescape_crlf(str *in_out)
{