SERVER-24033 Write full index spec in oplog entry for index creation.

This ensures that the index version (aka the "v" field) is always
present in the oplog entry when creating indexes on a 3.4 primary.
We can therefore assume that if the "v" field isn't present in the
corresponding oplog entry, then a v=1 index should be built.

Changes MultiBlockIndex::init() to return the index specifications
that were actually created.

The "repairDatabase", "compact", "copydb", and "cloneCollection"
commands no longer automatically upgrade the index version to the
current default version. Instead, the only command that does so is
the "reIndex" command.

1 files changed, 7 insertions, 1 deletions

diff --git a/src/mongo/dbtests/querytests.cpp b/src/mongo/dbtests/querytests.cpp
index 888d9bd4454..de55f54f45d 100644
--- a/src/mongo/dbtests/querytests.cpp
+++ b/src/mongo/dbtests/querytests.cpp
@@ -40,6 +40,7 @@
 #include "mongo/db/dbdirectclient.h"
 #include "mongo/db/dbhelpers.h"
 #include "mongo/db/global_timestamp.h"
+#include "mongo/db/index/index_descriptor.h"
 #include "mongo/db/json.h"
 #include "mongo/db/lasterror.h"
 #include "mongo/db/query/find.h"
@@ -56,6 +57,10 @@ using std::endl;
 using std::string;
 using std::vector;
 
+namespace {
+const auto kIndexVersion = IndexDescriptor::IndexVersion::kV2;
+}  // namespace
+
 class Base {
 public:
     Base() : _scopedXact(&_txn, MODE_X), _lk(_txn.lockState()), _context(&_txn, ns()) {
@@ -89,7 +94,8 @@ protected:
     }
 
     void addIndex(const BSONObj& key) {
-        Helpers::ensureIndex(&_txn, _collection, key, false, key.firstElementFieldName());
+        Helpers::ensureIndex(
+            &_txn, _collection, key, kIndexVersion, false, key.firstElementFieldName());
     }
 
     void insert(const char* s) {