SERVER-23377 Make sure _migrateClone always advances to next document

2 files changed, 15 insertions, 15 deletions

diff --git a/src/mongo/db/s/SConscript b/src/mongo/db/s/SConscript
index 83ab621ca27..85a559085ab 100644
--- a/src/mongo/db/s/SConscript
+++ b/src/mongo/db/s/SConscript
@@ -82,6 +82,7 @@ env.Library(
         'set_shard_version_command.cpp',
     ],
     LIBDEPS=[
+        '$BUILD_DIR/mongo/db/commands',
         '$BUILD_DIR/mongo/db/repl/repl_coordinator_global',
         '$BUILD_DIR/mongo/s/serveronly',
         'metadata',
@@ -99,7 +100,7 @@ env.Library(
         'migration_chunk_cloner_source.cpp',
     ],
     LIBDEPS=[
-
+        '$BUILD_DIR/mongo/base',
     ],
 )
 
@@ -110,6 +111,7 @@ env.Library(
         'migration_chunk_cloner_source_legacy_commands.cpp',
     ],
     LIBDEPS=[
+        '$BUILD_DIR/mongo/db/commands',
         'migration_chunk_cloner',
     ],
     LIBDEPS_TAGS=[
diff --git a/src/mongo/db/s/migration_chunk_cloner_source_legacy.cpp b/src/mongo/db/s/migration_chunk_cloner_source_legacy.cpp
index 1cb8c5c3bda..a9b324eaaad 100644
--- a/src/mongo/db/s/migration_chunk_cloner_source_legacy.cpp
+++ b/src/mongo/db/s/migration_chunk_cloner_source_legacy.cpp
@@ -402,24 +402,22 @@ Status MigrationChunkClonerSourceLegacy::nextCloneBatch(OperationContext* txn,
     std::set<RecordId>::iterator it;
 
     for (it = _cloneLocs.begin(); it != _cloneLocs.end(); ++it) {
-        Snapshotted<BSONObj> doc;
-        if (!collection->findDoc(txn, *it, &doc)) {
-            // Document must have been deleted
-            continue;
-        }
-
-        // Use the builder size instead of accumulating the document sizes directly so that we take
-        // into consideration the overhead of BSONArray indices, and *always* append at least one
-        // document.
-        if (arrBuilder->arrSize() &&
-            (arrBuilder->len() + doc.value().objsize() + 1024) > BSONObjMaxUserSize) {
+        // We must always make progress in this method by at least one document because empty return
+        // indicates there is no more initial clone data.
+        if (arrBuilder->arrSize() && tracker.intervalHasElapsed()) {
             break;
         }
 
-        arrBuilder->append(doc.value());
+        Snapshotted<BSONObj> doc;
+        if (collection->findDoc(txn, *it, &doc)) {
+            // Use the builder size instead of accumulating the document sizes directly so that we
+            // take into consideration the overhead of BSONArray indices.
+            if (arrBuilder->arrSize() &&
+                (arrBuilder->len() + doc.value().objsize() + 1024) > BSONObjMaxUserSize) {
+                break;
+            }
 
-        if (tracker.intervalHasElapsed()) {
-            break;
+            arrBuilder->append(doc.value());
         }
     }