src/vs/code/electron-sandbox/issue/issueReporterMain.ts/IssueReporter/setSourceOptions
class IssueReporter:	private setSourceOptions(): void {
		const sourceSelect = this.getElementById('issue-source')! as HTMLSelectElement;
		const { issueType, fileOnExtension, selectedExtension } = this.issueReporterModel.getData();
		let selected = sourceSelect.selectedIndex;
		if (selected === -1) {
			if (fileOnExtension !== undefined) {
				selected = fileOnExtension ? 2 : 1;
			} else if (selectedExtension?.isBuiltin) {
				selected = 1;
			}
		}

		sourceSelect.innerText = '';
		sourceSelect.append(this.makeOption('', localize('selectSource', "Select source"), true));
		sourceSelect.append(this.makeOption('vscode', localize('vscode', "Visual Studio Code"), false));
		sourceSelect.append(this.makeOption('extension', localize('extension', "An extension"), false));
		if (this.configuration.product.reportMarketplaceIssueUrl) {
			sourceSelect.append(this.makeOption('marketplace', localize('marketplace', "Extensions marketplace"), false));
		}

		if (issueType !== IssueType.FeatureRequest) {
			sourceSelect.append(this.makeOption('', localize('unknown', "Don't know"), false));
		}

		if (selected !== -1 && selected < sourceSelect.options.length) {
			sourceSelect.selectedIndex = selected;
		} else {
			sourceSelect.selectedIndex = 0;
			hide(this.getElementById('problem-source-help-text'));
		}
	}