Latest build breaks remote control on Mac M1 about gqrx HOT 15 CLOSED

I did know about the Qt5 issues, but I still have some legacy stuff that's never moved to 6 and trying to maintain both under Homebrew is real pain.

from gqrx.

Closing for now, since the bug was outside Gqrx.

from gqrx.

Processing of remote control commands was changed in #1343.

Perhaps you could record traffic on port 7356 using Wireshark to see what's going on.

from gqrx.

If you want to check whether that change made the difference, you could compare these two pre-release builds:

• https://github.com/gqrx-sdr/gqrx/actions/runs/8287395663 (before)
• https://github.com/gqrx-sdr/gqrx/actions/runs/8365249584 (after)

from gqrx.

Looking deeper, my initial assessment that it was the latest build is false. Turns out the last time I updated and built from github commits to master was 18 Feb, and apparently the remote code was updated mid-March. I generally do a github pull weekly, so I'm not sure how I missed it the code change. Let me investigate a little more and see if I can't see what's going on and give you better feedback.

from gqrx.

For whatever reason, it seems my version of Qt has a problem with QTcpSocket->canReadLine(), so the loop never gets entered. However, changing the first line in RemoteControl::startRead() from
while (rc_socket->canReadLine()) {
to
while (rc_socket->bytesAvailable() >= 2) {
seems to work fine as an alternative.

from gqrx.

Which version of Qt are you using?

Can you make a packet capture with Wireshark to see what's actually happening on the wire?

from gqrx.

Also, which operating system are you using?

from gqrx.

Does your client send a newline character at the end of each command?

from gqrx.

Do you observe the same problem if you connect to the remote control server "by hand" with nc / telnet?

from gqrx.

Will have to install wireshark and get back to you.
Qt is Qt 5.15.13
macOS is Sonoma 14.4.1 (arm)
and I believe client adds \r instead of \n at the end - which could be part of the problem.

from gqrx.

Qt is Qt 5.15.13

It's probably worth updating to Qt 6, since there's at least one known bug affecting Qt 5 on modern macOS: #1073

and I believe client adds \r instead of \n at the end

If so, that's likely the issue. canReadLine expects \n.

from gqrx.

Actually... that was indeed the problem. Changed all my \r to \n, reinserted canReadLine() in the while statement and now it works just fine. #StupidLegacyMacTrix.

So of course something named canreadline() is just going to wait until it sees a newline character. My bad, cheers.

from gqrx.

I'm glad to hear that switching to \n solved it. I'm a bit surprised that the readLine was working, since it also reads until the first \n, but maybe it bails out if one never shows up.

Hopefully this change in behaviour doesn't affect any other clients. I guess time will tell.

from gqrx.

Now I have to figure out why a months-old change is just hitting me now... unless I got distracted by other shiny things and simply forgot to revisit.

from gqrx.