src/vs/editor/browser/widget/diffEditorWidget.ts/isCharChangeOrInsert
function isCharChangeOrInsert(charChange: ICharChange): boolean {
	if (charChange.modifiedStartLineNumber === charChange.modifiedEndLineNumber) {
		return charChange.modifiedEndColumn - charChange.modifiedStartColumn > 0;
	}
	return charChange.modifiedEndLineNumber - charChange.modifiedStartLineNumber > 0;
}