Make immediate window buffer writable before applying completion edit

[tmat]

Customer scenario

VS crashes when completion in Immediate Window is committed by double-clicking on the completion item.

Bugs this fixes

VSO 384025
#24565

Workarounds, if any

Complete using tab.

Risk

Small.

Performance impact

None.

Is this a regression from a previous update?

Root cause analysis

How was the bug found?

Customer reported.

Test documentation updated?

[tmat]

@dotnet/roslyn-ide Please review.
@AmadeusW FYI.

[jasonmalinowski]

We also have this same stuff going on in DebuggerIntellisenseFilter.cs:

roslyn/src/VisualStudio/Core/Def/Implementation/DebuggerIntelliSense/DebuggerIntellisenseFilter.cs

Lines 98 to 99 in 70c4eaf

	_context.DebuggerTextLines.GetStateFlags(out var bufferFlags);
	_context.DebuggerTextLines.SetStateFlags((uint)((BUFFERSTATEFLAGS)bufferFlags & ~BUFFERSTATEFLAGS.BSF_USER_READONLY));

Was this the right place for that all along? It seems like yes, because commits indeed can come through not through the commanding system. Should that other code be deleted?

[tmat]

I think the other code needs to stay there so that characters are written to to buffer as you type.

[jasonmalinowski]

@AmadeusW Do we have this happening in our new system as well?

[jasonmalinowski]

@dpoeschl is the editor taking care of this magic in the new implementation?

[tmat]

@jasonmalinowski This hack is needed because of the way the Immediate Window works. Has nothing to do with editor. The right fix is to kill Immediate Window with fire.

[jasonmalinowski]

Has nothing to do with editor.

In the new intellisense implementation, the file you're editing no longer exists -- it's moved over to the editor. They already have to reimplement other hacks to deal with debugger windows, because we can't fix them anymore either.

[tmat]

test windows_release_vs-integration_prtest please

[tmat]

@jasonmalinowski I see. Hmm.

[jasonmalinowski]

This seems fine, but I'd like @AmadeusW's or @dpoeschl's signoff mostly so they are aware of this requirement and can incorporate into any new system.

[tmat]

So the editor now has dependency on Immediate Window? That's very unfortunate.

[AmadeusW]

@jasonmalinowski we do not have special handling for this. This is unfortunate that immediate window acts this way. Once we have working Roslyn bits, we will be able to solve this. I will create a dev16 bug to track this.

[AmadeusW]

Approved. I assigned myself bug 640224: In Async Completion, mark the immediate window's buffer as non-read-only during commit

[AmadeusW]

I can't approve 😭
I'll give a thumbs up instead.

[tmat]

test windows_release_vs-integration_prtest please

[tmat]

@jinujoseph for 15.8 approval

[jinujoseph]

Approved to merge for 15.8.Preview5