src/vs/workbench/services/dialogs/browser/simpleFileDialog.ts/SimpleFileDialog/setActiveItems
class SimpleFileDialog:	private setActiveItems(value: string) {
		value = this.pathFromUri(this.tildaReplace(value));
		const inputBasename = resources.basename(this.remoteUriFrom(value));
		const userPath = this.constructFullUserPath();
		// Make sure that the folder whose children we are currently viewing matches the path in the input
		const pathsEqual = equalsIgnoreCase(userPath, value.substring(0, userPath.length)) ||
			equalsIgnoreCase(value, userPath.substring(0, value.length));
		if (pathsEqual) {
			let hasMatch = false;
			for (let i = 0; i < this.filePickBox.items.length; i++) {
				const item = <FileQuickPickItem>this.filePickBox.items[i];
				if (this.setAutoComplete(value, inputBasename, item)) {
					hasMatch = true;
					break;
				}
			}
			if (!hasMatch) {
				const userBasename = inputBasename.length >= 2 ? userPath.substring(userPath.length - inputBasename.length + 2) : '';
				this.userEnteredPathSegment = (userBasename === inputBasename) ? inputBasename : '';
				this.autoCompletePathSegment = '';
				this.filePickBox.activeItems = [];
			}
		} else {
			this.userEnteredPathSegment = inputBasename;
			this.autoCompletePathSegment = '';
			this.filePickBox.activeItems = [];
		}
	}