SERVER-42260 IndexCatalog should add the 'ns' field to the index spec if it's missingr4.2.0-rc3

2 files changed, 12 insertions, 6 deletions

diff --git a/src/mongo/db/catalog/index_catalog_impl.cpp b/src/mongo/db/catalog/index_catalog_impl.cpp
index ac6a49d7fba..670622a17be 100644
--- a/src/mongo/db/catalog/index_catalog_impl.cpp
+++ b/src/mongo/db/catalog/index_catalog_impl.cpp
@@ -552,13 +552,12 @@ Status IndexCatalogImpl::_isSpecOk(OperationContext* opCtx, const BSONObj& spec)
     if (nss.isOplog())
         return Status(ErrorCodes::CannotCreateIndex, "cannot have an index on the oplog");
 
-    // If we stop generating the 'ns' field for index specs during testing, then we shouldn't
-    // validate that the 'ns' field is missing.
-    if (!disableIndexSpecNamespaceGeneration.load()) {
+    // If the index spec has the 'ns' field and if we don't stop generating the 'ns' field during
+    // testing, validate that it is correct.
+    if (spec.hasField("ns") && !disableIndexSpecNamespaceGeneration.load()) {
         const BSONElement specNamespace = spec["ns"];
         if (specNamespace.type() != String)
-            return Status(ErrorCodes::CannotCreateIndex,
-                          "the index spec is missing a \"ns\" string field");
+            return Status(ErrorCodes::CannotCreateIndex, "the \"ns\" field is not a string");
 
         if (nss.ns() != specNamespace.valueStringData())
             return Status(ErrorCodes::CannotCreateIndex,
@@ -1720,6 +1719,12 @@ StatusWith<BSONObj> IndexCatalogImpl::_fixIndexSpec(OperationContext* opCtx,
     }
     b.append("name", name);
 
+    // The 'ns' field was removed from index specs in v4.4 and could be missing when running with
+    // mixed version nodes.
+    if (!spec.hasField("ns") && !disableIndexSpecNamespaceGeneration.load()) {
+        b.append("ns", collection->ns().ns());
+    }
+
     {
         BSONObjIterator i(o);
         while (i.more()) {
diff --git a/src/mongo/db/index/index_descriptor.cpp b/src/mongo/db/index/index_descriptor.cpp
index edae421b9f6..e400c3c0df2 100644
--- a/src/mongo/db/index/index_descriptor.cpp
+++ b/src/mongo/db/index/index_descriptor.cpp
@@ -62,7 +62,8 @@ void populateOptionsMap(std::map<StringData, BSONElement>& theMap, const BSONObj
                 IndexDescriptor::kBackgroundFieldName ||  // this is a creation time option only
             fieldName == IndexDescriptor::kDropDuplicatesFieldName ||  // this is now ignored
             fieldName == IndexDescriptor::kSparseFieldName ||          // checked specially
-            fieldName == IndexDescriptor::kUniqueFieldName             // check specially
+            fieldName == IndexDescriptor::kUniqueFieldName ||          // check specially
+            fieldName == IndexDescriptor::kNamespaceFieldName          // removed in 4.4
             ) {
             continue;
         }