"Unable to open 'Unknown Source'" if StackFrame.source is missing

[Gama11]

As I understand, StackFrame.source in the debug protocol is supposed to be optional (because there might not always be a source location available). However, starting with VSCode 1.9.0, a missing source causes the following error (after a pause request response, might happen elsewhere too):

(btw: same thing with a source that is present, but has no path)

At first glance, this makes it look like pausing didn't work. However, at a second glance, pausing and resuming still works fine, so it's mostly a cosmetic issue (that still might lead the user to think it's broken).

Here's what our debug adapter (Haxe Debug) sends:

This works fine (no error appears) in 1.8.1, which would make this a regression. The issue is still present in the latest Insider's build (1d17b45).

Other debug adapters seem to have the same issue, as suggested by this StackOverflow question regarding the same error message with ASP.NET.

Issue #4608 seems somewhat related to this.

[infinisuite]

I'm still having this issue using the latest build as well as Insiders (updated today).

VS Code: v.1.9.1
TypeScript: 2.1.6
OS: OSX
Browser: Chrome
Debugger: Debugger for Chrome

[isidorn]

@Gama11 does the fix work for you? Namely vscode should simply not open the source if it is missing which would prevent the error.

[Gama11]

@isidorn Yes, it works if our debug adapter sends a stackframe like the one in the screenshot of my original post (one without a source).

Our debug adapter used to send messages like this, where source is present, but path is null - with this, I can still reproduce the error on Insider's:

I just assumed that that was incorrect API usage / not supposed to work anyway - it always showed the path as null in the call stack rather than detecting it as Unknown Source:

Even though in 1.8.1, this didn't error, but it actually opened a <null> file, which doesn't seem correct either:

[isidorn]

@Gama11 thanks. Yes that is how it is supposed to work now. Adding verified label