Terminal commands are not reliable when conpty dll is false

[Tyriar]

I found that conpty shipped with Windows is a major cause of the terminal hangs, this is the default on stable(!)

Notice SI didn't work properly on the left.

[Tyriar]

Fairly reliable repro:

run the following as separate terminal commands:

- echo "This is a readme file" > README_2.md
- cat README_2.md

[Tyriar]

Exthost events when this happens:

[Extension Host] *** onDidChangeTerminalShellIntegration {terminal: {…}, shellIntegration: '[Circular]'} (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))
console.ts:137 [Extension Host] *** onDidChangeTerminalShellIntegration {terminal: {…}, shellIntegration: '[Circular]'} (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))
console.ts:137 [Extension Host] *** onDidChangeTerminalShellIntegration {terminal: {…}, shellIntegration: '[Circular]'} (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))
console.ts:137 [Extension Host] *** onDidStartTerminalShellExecution {terminal: {…}, shellIntegration: '[Circular]', execution: {…}} (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))
console.ts:137 [Extension Host] data �]633;C� (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))
console.ts:137 [Extension Host] data  (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))
console.ts:137 [Extension Host] *** onDidEndTerminalShellExecution {terminal: {…}, shellIntegration: '[Circular]', execution: {…}, exitCode: 0} (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))
console.ts:137 [Extension Host] *** onDidStartTerminalShellExecution {terminal: {…}, shellIntegration: '[Circular]', execution: {…}} (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))
console.ts:137 [Extension Host] data �]633;C�This is a readme file
�]633;D;0��]633;A��]633;P;Cwd=C:\x5cGithub\x5cTyriar\x5cxterm.js��]633;EnvJson;{................};249e4dc3-5a9b-4d74-959f-8f374893b48d�PS C:\Github\Tyriar\xterm.js> �]633;P;Prompt=PS C:\x5cGithub\x5cTyriar\x5cxterm.js> ��]633;B� (at console.<anonymous> (file:///d:/microsoft/vscode/out/vs/workbench/api/common/file:/D:/microsoft/vscode/src/vs/workbench/api/common/extHostConsoleForwarder.ts:50:10))

[Tyriar]

Command finished never fires as the second command is marked invalid

[Tyriar]

A lot of context/examples in #254447

[Tyriar]

Commenting out this line fixes it, but obvious would break the invalidation mechanism:

vscode/src/vs/platform/terminal/common/capabilities/commandDetectionCapability.ts

Line 174 in 01fc0c9

this._currentCommand.isInvalid = true;