Comment 4 for bug 1916501

I think I’ve come to kind of understood what might be wrong: qemu frees CURLSocket objects when “their” transfer is done, but libcurl’s documentation actually doesn’t note any long-lasting relationship between a socket and some transfer (i.e., a CURL object), so we probably shouldn’t free CURLSocket objects just because some transfer is done. Instead, we should only do so once libcurl explicitly tells us to remove the socket.

I’ve sent a two-patch series to that effect: https://lists.nongnu.org/archive/html/qemu-block/2021-03/msg00515.html – it seems to help.