Function coverage_normalize_rel

src/mcp/mcp.c:4128–4178

Normalize an untrusted repository-relative path without touching the * filesystem. Absolute paths, drive/UNC paths, control bytes, and any `..` * component are rejected. A root scope (`.`) normalizes to the empty prefix. */

 * filesystem. Absolute paths, drive/UNC paths, control bytes, and any `..`
 * component are rejected. A root scope (`.`) normalizes to the empty prefix. */
static coverage_path_result_t coverage_normalize_rel(const char *input, bool allow_root, char *out,
                                                     size_t out_size) {
    if (!input || !out || out_size == 0U) {
        return COVERAGE_PATH_INVALID;
    }
    out[0] = '\0';
    size_t len = strlen(input);
    if (len == 0U || len >= out_size || input[0] == '/' || input[0] == '\\' ||
        (len >= 2U && isalpha((unsigned char)input[0]) && input[1] == ':')) {
        return COVERAGE_PATH_OUTSIDE;
    }

    size_t in = 0U;
    size_t written = 0U;
    while (in < len) {
        while (in < len && (input[in] == '/' || input[in] == '\\')) {
            in++;
        }
        if (in >= len) {
            break;
        }
        size_t start = in;
        while (in < len && input[in] != '/' && input[in] != '\\') {
            unsigned char c = (unsigned char)input[in];
            if (c < 0x20U) {
                return COVERAGE_PATH_INVALID;
            }
            in++;
        }
        size_t part_len = in - start;
        if (part_len == 1U && input[start] == '.') {
            continue;
        }
        if (part_len == 2U && input[start] == '.' && input[start + 1U] == '.') {
            return COVERAGE_PATH_OUTSIDE;
        }
        if (written > 0U) {
            if (written + 1U >= out_size) {
                return COVERAGE_PATH_INVALID;
            }
            out[written++] = '/';
        }
        if (written + part_len >= out_size) {
            return COVERAGE_PATH_INVALID;
        }
        memcpy(out + written, input + start, part_len);
        written += part_len;
    }
    out[written] = '\0';
    return written > 0U || allow_root ? COVERAGE_PATH_OK : COVERAGE_PATH_INVALID;
}

static int64_t coverage_stat_mtime_ns(const struct stat *st) {
#ifdef __APPLE__