Clear pendingValidatedCheckpoint on new checkpoints.

Author: rkistner

packages/common/src/client/sync/stream/AbstractStreamingSyncImplementation.ts

@@ -708,6 +708,8 @@ The next upload iteration will be delayed.`);
 
       if (isStreamingSyncCheckpoint(line)) {
         targetCheckpoint = line.checkpoint;
+        // New checkpoint - existing validated checkpoint is no longer valid
+        pendingValidatedCheckpoint = null;
         const bucketsToDelete = new Set<string>(bucketMap.keys());
         const newBuckets = new Map<string, BucketDescription>();
         for (const checksum of line.checkpoint.buckets) {
@@ -729,7 +731,13 @@ The next upload iteration will be delayed.`);
         if (result.endIteration) {
           return;
         } else if (!result.applied) {
+          // "Could not apply checkpoint due to local data". We need to retry after
+          // finishing uploads.
           pendingValidatedCheckpoint = targetCheckpoint;
+        } else {
+          // Nothing to retry later. This would likely already be null from the last
+          // checksum or checksum_diff operation, but we make sure.
+          pendingValidatedCheckpoint = null;
         }
       } else if (isStreamingSyncCheckpointPartiallyComplete(line)) {
         const priority = line.partial_checkpoint_complete.priority;
@@ -765,6 +773,8 @@ The next upload iteration will be delayed.`);
         if (targetCheckpoint == null) {
           throw new Error('Checkpoint diff without previous checkpoint');
         }
+        // New checkpoint - existing validated checkpoint is no longer valid
+        pendingValidatedCheckpoint = null;
         const diff = line.checkpoint_diff;
         const newBuckets = new Map<string, BucketChecksum>();
         for (const checksum of targetCheckpoint.buckets) {