src/vs/workbench/contrib/mergeEditor/browser/model/modifiedBaseRange.ts/ModifiedBaseRange/getEditForBase
class ModifiedBaseRange:	public getEditForBase(state: ModifiedBaseRangeState): { edit: LineRangeEdit | undefined; effectiveState: ModifiedBaseRangeState } {
		const diffs: { diff: DetailedLineRangeMapping; inputNumber: InputNumber }[] = [];
		if (state.includesInput1 && this.input1CombinedDiff) {
			diffs.push({ diff: this.input1CombinedDiff, inputNumber: 1 });
		}
		if (state.includesInput2 && this.input2CombinedDiff) {
			diffs.push({ diff: this.input2CombinedDiff, inputNumber: 2 });
		}

		if (diffs.length === 0) {
			return { edit: undefined, effectiveState: ModifiedBaseRangeState.base };
		}
		if (diffs.length === 1) {
			return { edit: diffs[0].diff.getLineEdit(), effectiveState: ModifiedBaseRangeState.base.withInputValue(diffs[0].inputNumber, true, false) };
		}

		if (state.kind !== ModifiedBaseRangeStateKind.both) {
			throw new BugIndicatingError();
		}

		const smartCombinedEdit = state.smartCombination ? this.smartCombineInputs(state.firstInput) : this.dumbCombineInputs(state.firstInput);
		if (smartCombinedEdit) {
			return { edit: smartCombinedEdit, effectiveState: state };
		}

		return {
			edit: diffs[getOtherInputNumber(state.firstInput) - 1].diff.getLineEdit(),
			effectiveState: ModifiedBaseRangeState.base.withInputValue(
				getOtherInputNumber(state.firstInput),
				true,
				false
			),
		};
	}