hwPortUtils.listComPorts: Querying PortName can fail

[jcsteh]

Originally reported by @mohdshara in this nvda-devel thread.

It seems that some com ports don't have a PortName registry value:

ERROR - unhandled exception (15:22:32):
Traceback (most recent call last):
  File "gui\settingsDialogs.pyo", line 1537, in onDisplayNameChanged
  File "gui\settingsDialogs.pyo", line 1544, in updatePossiblePorts
  File "brailleDisplayDrivers\baum.pyo", line 117, in getPossiblePorts
  File "hwPortUtils.pyo", line 192, in listComPorts
WindowsError: [Error 2] The system cannot find the file specified

Unless I'm missing something, this is broken, but clearly, it can happen. I guess we should just catch the error and skip the port.

[nvaccessAuto]

Incubated in 73ee6b2.

[mohdshara]

Wonderful! thank you very much for looking into it and for fixing the issue. confirmed, I can now connect through USP and bluetooth.

[mohdshara]

Hi. It may be worth noting here, that this happened to me on 3 different laptops. They are all made by Linovo and all have windows 10 64 bit. of course, this commit fixes the issues on all of them. what I am trying to say is that there maybe a pattern here.

[jcsteh]

That would suggest Lenovo are installing something that creates this issue. It'd be interesting to see a log file at level debugWarning covering selecting a Baum display with this new build on one of those computers. The build logs some info when it encounters this issue. There's nothing we can do about it, but seeing the log might give me some idea of what this actually is.

[mohdshara]

attached are the log files with a usp connection and another with a bluetooth connection.

nvda-log-bluetooth-lenovo.txt
nvda-log-usb.txt
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[jcsteh]

Looks like the problematic port is a modem (hardware id: USB\Vid_0bdb&Pid_193e&Cdc_Modem&Mi_03), so it's not important. That's good.

However, I did notice you're connecting via Bluetooth by choosing a specific com port, rather than selecting automatic 'as the port and letting NVDA detect. Is automatic not working for you with Bluetooth?

[mohdshara]

Hi Jamie.

I was manually selecting a port because that was what Baum suggested. however, I have just tried, and I found out that automatic will now work too.

Thanks for your help and for fixing the issue.