Fix skipping more empty boundaries than the size of the query

spec/marker-text-decoration-layer-spec.js

@@ -103,15 +103,16 @@ describe('MarkerTextDecorationLayer', () => {
     it('fetches boundaries as needed based on the boundariesPerQuery parameter', () => {
       const buffer = new TextBuffer({text: 'abcdef\n'.repeat(20)})
       const markerLayer = buffer.addMarkerLayer()
-      markerLayer.markRange([[0, 2], [1, 2]])
-      markerLayer.markRange([[2, 2], [3, 2]])
-      markerLayer.markRange([[3, 2], [4, 2]])
-      markerLayer.markRange([[10, 2], [11, 2]])
-      markerLayer.markRange([[12, 2], [13, 2]])
+      const marker1 = markerLayer.markRange([[0, 2], [1, 2]])
+      const marker2 = markerLayer.markRange([[2, 2], [3, 2]])
+      const marker3 = markerLayer.markRange([[3, 2], [4, 2]])
+      const marker4 = markerLayer.markRange([[10, 2], [11, 2]])
+      const marker5 = markerLayer.markRange([[12, 2], [13, 2]])
 
+      const decoratedMarkerIds = new Set([marker1.id, marker2.id, marker3.id, marker4.id, marker5.id])
       const textDecorationLayer = new MarkerTextDecorationLayer(markerLayer, {
         boundariesPerQuery: 3,
-        classNameForMarkerId: () => 'foo'
+        classNameForMarkerId: (markerId) => decoratedMarkerIds.has(markerId) ? 'foo' : null
       })
 
       const iterator = textDecorationLayer.buildIterator()
@@ -133,6 +134,14 @@ describe('MarkerTextDecorationLayer', () => {
       expect(iterator.getPosition()).toEqual(Point(12, 2))
       iterator.moveToSuccessor()
       expect(iterator.getPosition()).toEqual(Point(13, 2))
+
+      // Ensure skipping more empty boundaries than the size of the query works correctly.
+      decoratedMarkerIds.delete(marker1.id)
+      decoratedMarkerIds.delete(marker2.id)
+      iterator.seek(Point(0, 0))
+      expect(iterator.getPosition()).toEqual(Point(3, 2))
+      iterator.moveToSuccessor()
+      expect(iterator.getPosition()).toEqual(Point(4, 2))
     })
   })
 

src/marker-text-decoration-layer.js

@@ -79,23 +79,24 @@ class MarkerTextDecorationLayerIterator {
   }
 
   moveToSuccessor () {
-    if (this.boundaryIndex === this.boundaries.length) return
-
-    // Fetch more marker boundaries if needed
-    if (this.boundaryIndex === this.boundaries.length - 1) {
-      const {row, column} = this.getPosition()
-      const {boundaries} = this.layer.markerLayer.index.findBoundariesAfter(
-        Point(row, column + 1),
-        this.layer.boundariesPerQuery
-      )
-      this.boundaries = boundaries
-      this.boundaryIndex = -1
-    }
+    if (this.boundaries.length === 0) return
 
     do {
-      this.boundaryIndex++
+      // Fetch more marker boundaries if needed
+      if (this.boundaryIndex === this.boundaries.length - 1) {
+        const {row, column} = this.getPosition()
+        const {boundaries} = this.layer.markerLayer.index.findBoundariesAfter(
+          Point(row, column + 1),
+          this.layer.boundariesPerQuery
+        )
+        this.boundaries = boundaries
+        this.boundaryIndex = 0
+      } else {
+        this.boundaryIndex++
+      }
+
       this.computeScopeIds()
-    } while (this.openScopeIds.length === 0 && this.closeScopeIds.length === 0 && this.boundaryIndex < this.boundaries.length)
+    } while (this.openScopeIds.length === 0 && this.closeScopeIds.length === 0 && this.boundaries.length > 0)
   }
 
   getPosition () {