#line 12 "unescape.c-nw"
#include <config.h>
#include <str.h>

static char hextoc(char *s)
{
    char c;

    if ('0' <= *s && *s <= '9') c = 16 * (*s - '0');
    else if ('a' <= *s && *s <= 'f') c = 16 * (*s - 'a' + 10);
    else if ('A' <= *s && *s <= 'F') c = 16 * (*s - 'A' + 10);
    else return '%';                            /* Error! */
    s++;
    if ('0' <= *s && *s <= '9') c += *s - '0';
    else if ('a' <= *s && *s <= 'f') c += *s - 'a' + 10;
    else if ('A' <= *s && *s <= 'F') c += *s - 'A' + 10;
    else return '%';                            /* Error! */
    return c;
}

EXPORT char *URL_unescape(char *s)
{
    char *p = s, *q;

    if (! p) return NULL;

    while (*p && *p != '%' && *p != '+') p++;

    if (*p) {
        for (q = p; *p; q++) {
            if (*p == '%' && isxdigit(*(p+1)) && isxdigit(*(p+2))) {
                *q = hextoc(p + 1);
                p += 3;
            } else if (*p == '+') {
                *q = ' ';
                p++;
            } else
                *q = *(p++);
        }
        *q = '\0';
    }
    return s;
}