SERVER-17487 Use strict unindex operations for in-progress indexes

(cherry picked from commit 378f8dd985cb3c8d03b384d9671abff92693c7f5)

2 files changed, 7 insertions, 0 deletions

diff --git a/src/mongo/db/catalog/index_catalog.cpp b/src/mongo/db/catalog/index_catalog.cpp
index 3e00ed23121..24736eb590b 100644
--- a/src/mongo/db/catalog/index_catalog.cpp
+++ b/src/mongo/db/catalog/index_catalog.cpp
@@ -1088,6 +1088,11 @@ namespace {
         options.logIfError = logIfError;
         options.dupsAllowed = isDupsAllowed( index->descriptor() );
 
+        // For unindex operations, dupsAllowed=false really means that it is safe to delete anything
+        // that matches the key, without checking the RecordID, since dups are impossible. We need
+        // to disable this behavior for in-progress indexes. See SERVER-17487 for more details.
+        options.dupsAllowed = options.dupsAllowed || !index->isReady(txn);
+
         int64_t removed;
         Status status = index->accessMethod()->remove(txn, obj, loc, options, &removed);
 
diff --git a/src/mongo/db/cloner.cpp b/src/mongo/db/cloner.cpp
index 5e691f3b4c9..f0682da2e44 100644
--- a/src/mongo/db/cloner.cpp
+++ b/src/mongo/db/cloner.cpp
@@ -639,6 +639,8 @@ namespace mongo {
                     uassertStatusOK(indexer.init(c->getIndexCatalog()->getDefaultIdIndexSpec()));
                     uassertStatusOK(indexer.insertAllDocumentsInCollection(&dups));
 
+                    // This must be done before we commit the indexer. See the comment about
+                    // dupsAllowed in IndexCatalog::_unindexRecord and SERVER-17487.
                     for (set<RecordId>::const_iterator it = dups.begin(); it != dups.end(); ++it) {
                         WriteUnitOfWork wunit(txn);
                         BSONObj id;