GCC crash because of -Werror=implicit-fallthrough. However the fallthrough exists but has a typo.
Thanks for omac777 analysis (7d0b8155a3)
However the fallthrough exists but has a typo
(cherry picked from commit ea0c714139)
This is counterpart of 5774c78 "qfile-agent: move data handling code to
libqubes-rpc-filecopy" in core-agent-linux. The main purpose is to
easily reuse the code in dom0 qvm-copy-to-vm tool.
QubesOS/qubes-issues#1324