src/vs/workbench/contrib/mergeEditor/browser/model/mergeEditorModel.ts/MergeEditorModel/updateBaseRangeAcceptedState
class MergeEditorModel:	private updateBaseRangeAcceptedState(resultDiffs: DetailedLineRangeMapping[], states: Map<ModifiedBaseRange, ModifiedBaseRangeData>, tx: ITransaction): void {
		const baseRangeWithStoreAndTouchingDiffs = leftJoin(
			states,
			resultDiffs,
			(baseRange, diff) =>
				baseRange[0].baseRange.touches(diff.inputRange)
					? CompareResult.neitherLessOrGreaterThan
					: LineRange.compareByStart(
						baseRange[0].baseRange,
						diff.inputRange
					)
		);

		for (const row of baseRangeWithStoreAndTouchingDiffs) {
			const newState = this.computeState(row.left[0], row.rights);
			const data = row.left[1];
			const oldState = data.accepted.get();
			if (!oldState.equals(newState)) {
				if (!this.firstRun && !data.computedFromDiffing) {
					// Don't set this on the first run - the first run might be used to restore state.
					data.computedFromDiffing = true;
					data.previousNonDiffingState = oldState;
				}
				data.accepted.set(newState, tx);
			}
		}

		if (this.firstRun) {
			this.firstRun = false;
		}
	}