Cryptic error when XUL path is wrong

[1j01]

Instead of something like file not found: C:/Users/Isaiah/Projects/98.js-vr/shell.xul, I got:

JavaScript error: jar:file:///C:/Users/Isaiah/Projects/98.js-vr/node_modules/qbrt/dist/win32/runtime/omni.ja!/components/nsPrompter.js, line 340: NS_ERROR_NOT_AVAILABLE: Cannot call openModalWindow on a hidden window

(after copying the shell example code over but with a different name for the xul file)

I fixed it pretty quickly, but not from any information in that error message!

[1j01]

Oh, looks like there's already a lil todo for it in the example code:

qbrt/shell/main.js

Lines 40 to 41 in 76a2960

	// TODO: report error if URL isn't found.
	Services.ww.openWindow(null, SHELL_URL, '_blank', WINDOW_FEATURES, argument);

[mykmelez]

Indeed, this is a terrible error message, very unclear. Unfortunately, Services.ww.openWindow() doesn't throw when the URL isn't found, which makes this complicated to fix. We might try parsing the URL first to confirm that it corresponds to a known location on the local filesystem (or is a remote URL) before calling Services.ww.openWindow().