SERVER-45089 Assert force reconfig with missing term field results in default -1 term

2 files changed, 19 insertions, 2 deletions

diff --git a/jstests/replsets/reconfig_ignores_term_field.js b/jstests/replsets/reconfig_ignores_term_field.js
index 2cc48ac950d..82971834432 100644
--- a/jstests/replsets/reconfig_ignores_term_field.js
+++ b/jstests/replsets/reconfig_ignores_term_field.js
@@ -26,5 +26,20 @@ replTest.awaitReplication();
 
 config = primary.getDB("local").system.replset.findOne();
 assert.eq(config.term, 1);
+
+jsTestLog("Force reconfig ignores user provided term");
+config.term = 55;
+config.version++;
+assert.commandWorked(primary.getDB("admin").runCommand({replSetReconfig: config, force: true}));
+config = primary.getDB("local").system.replset.findOne();
+assert.eq(config.term, -1);
+
+jsTestLog("Force reconfig with missing term results in term -1");
+delete config.term;
+config.version++;
+assert.commandWorked(primary.getDB("admin").runCommand({replSetReconfig: config, force: true}));
+config = primary.getDB("local").system.replset.findOne();
+assert.eq(config.term, -1);
+
 replTest.stopSet();
 }());
\ No newline at end of file
diff --git a/src/mongo/db/repl/replication_coordinator_impl.cpp b/src/mongo/db/repl/replication_coordinator_impl.cpp
index 751f971a648..290223fc358 100644
--- a/src/mongo/db/repl/replication_coordinator_impl.cpp
+++ b/src/mongo/db/repl/replication_coordinator_impl.cpp
@@ -2922,7 +2922,6 @@ Status ReplicationCoordinatorImpl::processReplSetReconfig(OperationContext* opCt
         makeGuard([&] { lockAndCall(&lk, [=] { _setConfigState_inlock(kConfigSteady); }); });
 
     ReplSetConfig oldConfig = _rsConfig;
-    auto topCoordTerm = _topCoord->getTerm();
     lk.unlock();
 
     ReplSetConfig newConfig;
@@ -2936,7 +2935,10 @@ Status ReplicationCoordinatorImpl::processReplSetReconfig(OperationContext* opCt
 
     // When initializing a new config through the replSetReconfig command, ignore the term
     // field passed in through its args. Instead, use this node's term.
-    Status status = newConfig.initialize(newConfigObj, topCoordTerm, oldConfig.getReplicaSetId());
+    // If it is a force reconfig, explicitly set the term to -1.
+
+    auto term = !args.force ? _topCoord->getTerm() : OpTime::kUninitializedTerm;
+    Status status = newConfig.initialize(newConfigObj, term, oldConfig.getReplicaSetId());
     if (!status.isOK()) {
         LOGV2_ERROR(21418,
                     "replSetReconfig got {status} while parsing {newConfigObj}",