Crash when cache->file.name is not populated

[jaqq2]

Sometimes ngx_http_file_cache_open() returns before calling ngx_http_file_cache_name(), which will lead to a crash when later calling ngx_http_file_cache_update().

request should be declined instead of calling ngx_http_slowfs_static_send() if cache->file.name is empty, maybe with something like:

    rc = ngx_http_slowfs_cache_send(r);
-    if (rc == NGX_DECLINED) {
+    if ((rc == NGX_DECLINED) && (r->cache->file.name.len > 0)) {
        rc = ngx_http_slowfs_static_send(r);
    }

    return rc;
}

[runningman84]

Is this problem responsible for segfaults like this?
nginx[29893]: segfault at 0 ip 0000000000492b44 sp 00007ffffb73fad0 error 6 in nginx[400000+290000]