Merge pull request #7845 from overleaf/bg-snapshot-lost-tracked-changes

[document-updater] consider lost tracked-changes as collapsed ranges

GitOrigin-RevId: cf8e15c610f906f1296fdcdd69128ad1e029863a

services/document-updater/app/js/RangesManager.js

@@ -80,7 +80,9 @@ module.exports = RangesManager = {
 
     const [emptyRangeCountAfter, totalRangeCountAfter] =
       RangesManager._emptyRangesCount(rangesTracker)
-    const rangesWereCollapsed = emptyRangeCountAfter > emptyRangeCountBefore
+    const rangesWereCollapsed =
+      emptyRangeCountAfter > emptyRangeCountBefore ||
+      totalRangeCountAfter + 1 < totalRangeCountBefore // also include the case where multiple ranges were removed
     // monitor the change in range count, we may want to snapshot before large decreases
     if (totalRangeCountAfter < totalRangeCountBefore) {
       Metrics.histogram(