We use a file descriptor, so when we consume an entry, we move past it
(and everyone shares a file offset, so this works).
The file contains packet names prefixed by - (treat fd as closed when
we try to write this packet), + (write the packet then ensure the file
descriptor fails), or @ ("lose" the packet then ensure the file
descriptor fails).
The sync and async peer-write functions hook this in automatically.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Header from folded patch 'test-run-cryptomsg__fix_compilation.patch':
test/run-cryptomsg: fix compilation.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>