Uncaught TypeError: Cannot read property 'size' of undefined

[vscodeerrors]

Issue Id: eb15f202-a9cf-1bbb-9814-f224dae1c2d6

Versions
- 1.22.1
- 6c22e21
Stack
TypeError: Cannot read property 'size' of undefined
/vs/base/browser/ui/list/listView.ts#234:27 (elementHeight)
/vs/base/browser/ui/list/listWidget.ts#1105:34 (reveal)
/vs/base/browser/ui/selectBox/selectBoxCustom.ts#424:19 (layoutSelectDropDown)
/vs/base/browser/ui/selectBox/selectBoxCustom.ts#386:7 (renderSelectDropDown)
/vs/base/browser/ui/selectBox/selectBoxCustom.ts#360:44 (render)
/vs/base/browser/ui/contextview/contextview.ts#157:35 (show)
/vs/platform/contextview/browser/contextViewService.ts#38:19 (showContextView)
/vs/base/browser/ui/selectBox/selectBoxCustom.ts#358:27 (showSelectDropDown)
/vs/base/browser/ui/selectBox/selectBoxCustom.ts#164:9

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• Uncaught TypeError: Cannot read property 'size' of undefined (#43475)

[GongT]

doesn't fully fixed:

---

A:
this.select(undefined)
native select have a "no selection" state.

this.selectList.setFocus([this.selected]);
to
this.selectList.setFocus([this.selected || 0]);

can fix this. no selection dropdown is same as selected first element.

---

B:
new SelectBox([], undefined, ....)
native select can have no element.

but select box custom will throw this error.

[joaomoreno]

@cleidigh This can be reproduced by having an empty dropdown and simply opening it. There are many places in the code in which a selected number is assumed to exist. There are also many this.selectList.getFocus()[0]. When the dropdown is empty this returns undefined.

cc @bpasero

[bpasero]

Pushed a workaround for this particular crash via 68f1bc2

[TylerLeonhardt]

@bpasero no context on this issue but, I follow vscode on CodeTriage 😊 it looks like it could be closed?