fix priority calculation

Author: sokra

lib/reducePlan.js

@@ -70,12 +70,13 @@ module.exports = (plan, limit) => {
 	// Reduce until limit reached
 	while (currentCount > limit) {
 		// Select node that helps reaching the limit most effectively without overmerging
-		const overLimit = limit - currentCount;
+		const overLimit = currentCount - limit;
 		let bestNode = undefined;
 		let bestCost = Infinity;
 		for (const node of treeMap.values()) {
 			if (node.entries <= 1 || !node.children) continue;
-			if (node.children.length <= 1) continue;
+			if (node.children.length === 0) continue;
+			if (node.children.length === 1 && !node.value) continue;
 			// Try to select the node with has just a bit more entries than we need to reduce
 			// When just a bit more is over 30% over the limit,
 			// also consider just a bit less entries then we need to reduce