Crash when displaying emoji

[zb140]

Starting after I updated to the latest master today, I'm getting a crash when displaying at least some emoji. Commit bac69f7 is the most recent one I was able to find that definitely works. I tried bisecting to narrow it down further but ran into a bunch of build issues and gave up.

Running in a debugger I get this exception:

Unhandled exception at 0x00007FFF994F4B29 in WindowsTerminal.exe: Microsoft C++ exception: wil::ResultException at memory location 0x0000006A998FDE10.

The particular result being complained about is this: E_INVALIDARG One or more arguments are invalid..
The call stack seems to point to this line as being the problem:

terminal/src/renderer/base/renderer.cpp

Line 639 in 12d2e17

THROW_IF_FAILED(pEngine->PaintBufferLine({ clusters.data(), clusters.size() }, screenPoint, false));

(Technically it points to the next line, but I think that's just the debugger being funny).

This is 100% reproducible for me on both of the systems I've tried it on. I'm happy to help dig up more info if needed.

Environment

Windows build number: [run `[Environment]::OSVersion` for powershell, or `ver` for cmd]
10.0.18965.0 
I happen to be filing this from a system with a fairly recent Insider build, but this also happens on the latest non-Insider build.

Windows Terminal version (if applicable):
Latest from master

Any other software?
Powershell 6.2.2 (not sure if this matters)

Steps to reproduce

In Powershell:

PS> echo "$([char]0x2714)"

Expected behavior

Should print a ✔️

Actual behavior

The terminal crashes.

[jbolton-corvalgroup]

I cannot get a crash using PowerShell 5.1.18362.145, maybe it's a PowerShell core/6+ bug, not terminal ?

Tested on windows10.

bash, (specifically git-bash from github desktop in WindowsTerminal

$ python -c 'print(chr(0x2714))'
✔

cmd.exe in WindowsTerminal

C:\Users\john>python -c "print(chr(0x2714))"
✔

powershell 5 (non-core) from WindowsTerminal

PS C:\Users\john> [char]0x2714
✔

Because the above is in code fences, the character looks different. in the terminal it's: ✔

[zb140]

Whatever's going on on my systems doesn't seem to be related to Powershell. I've just now tried it in Powershell 5, in cmd.exe, in Git's bash, and even after sshing to a Linux host, and all of them crash in exactly the same way.

Which commit of Terminal are you using? I'm seeing these crashes in 2ac2497 on both of the systems I've tried it on. I see there are new commits this morning but I haven't tried them yet.

[j4james]

I can reproduce this too. And if you look at the debug output log from within the debugger, you can trace the source of the E_INVALIDARG to this line:

terminal/src/renderer/dx/CustomTextRenderer.cpp

Line 436 in d8ff47a

RETURN_HR_IF_NULL(E_INVALIDARG, glyphRunDescription);

But from what I can make out, the glyphRunDescription parameter is not actually required. It's documented as optional for the ID2D1DeviceContext::DrawGlyphRun method, which is where it's ultimately being used.

The glyphRunDescription is ignored when rendering, but can be useful for printing and serialization of rendering commands, such as to an XPS or SVG file

So I suspect that NULL check is probably a mistake. It was only recently added in commit 30e8e7f, and removing that line certainly fixes the problem for me.

cc @miniksa