Check what happens when patches attempt to edit or delete empty files.

if we've reached EOF without finding a match is fine if and only if the target file is empty, so add this exception. reported by naddy, ok stsp

Was suggested by Lucas some time ago. ok stsp@ with a tweak in the manual.

-R is needed on almost all other commands so this makes things consistent. Patch by Lorenz (xha)

Without this we exit the loop early and got-fetch-pack sees unexpected end-of-file on stdout trying to write its final "done\n" message. ok op@

so we can reuse it in other places like got-fetch-http later. ok op@ stsp@

tls_write() may return TLS_WANT_READ. In that case, we're stuck trying to read while we have the request still in the buffer. So, we have to retry bufio_write() regardless of the POLLIN/POLLOUT state. We'd need this only in the TLS case, but in practice it doesn't harm for the plaintext case too. In fact, we're either waiting to flush the request or we're only reading the server reply. ok stsp

ok op@

ok op@

ok op@

With HTTPS we only need to be able to read /etc/ssl/cert.pem. With plaintext HTTP no filesystem access is needed at all.