Function TryUriDecodeLen

extern/nfd/nfd_portal.cpp:963–982

Returns true if the given file URI is decodable (i.e. not malformed), and false otherwise. If this function returns true, then `out` will be populated with the length of the decoded URI and `fileUriEnd` will point to the trailing null byte of `fileUri`. Otherwise, `out` and `fileUriEnd` will be unmodified.

// and `fileUriEnd` will point to the trailing null byte of `fileUri`. Otherwise, `out` and
// `fileUriEnd` will be unmodified.
bool TryUriDecodeLen(const char* fileUri, size_t& out, const char*& fileUriEnd) {
    size_t len = 0;
    while (*fileUri) {
        if (*fileUri != '%') {
            ++fileUri;
        } else {
            if (*(fileUri + 1) == '\0' || *(fileUri + 2) == '\0') {
                return false;
            }
            if (!IsHex(*(fileUri + 1)) || !IsHex(*(fileUri + 2))) {
                return false;
            }
            fileUri += 3;
        }
        ++len;
    }
    out = len;
    fileUriEnd = fileUri;
    return true;
}

// Decodes the given URI and writes it to `outPath`.  The caller must ensure that the given URI is
// not malformed (typically with a prior call to `TryUriDecodeLen`).  This function does not write