SERVER-68477 TTL monitor skips indexes with NaN expireAfterSeconds

(cherry-picked from commit 14c07b53186ee88497abd0ba492d2d9157891718)

(cherry picked from commit 7d76329f8915ec80ba07c07e4a0adbc7fd187107)

2 files changed, 54 insertions, 6 deletions

diff --git a/jstests/noPassthrough/ttl_expire_nan.js b/jstests/noPassthrough/ttl_expire_nan.js
new file mode 100644
index 00000000000..5d26b214487
--- /dev/null
+++ b/jstests/noPassthrough/ttl_expire_nan.js
@@ -0,0 +1,45 @@
+/**
+ * Tests TTL indexes with NaN for 'expireAfterSeconds'.
+ *
+ * Existing TTL indexes from older versions of the server may contain a NaN for the duration.
+ * Newer server versions (5.0+) normalize the TTL duration to 0.
+ *
+ * @tags: [
+ *     requires_replication,
+ * ]
+ */
+(function() {
+'use strict';
+
+const rst = new ReplSetTest({
+    nodes: [{}, {rsConfig: {votes: 0, priority: 0}}],
+    nodeOptions: {setParameter: {ttlMonitorSleepSecs: 5}},
+});
+rst.startSet();
+rst.initiate();
+
+let primary = rst.getPrimary();
+const db = primary.getDB('test');
+const coll = db.t;
+
+assert.commandWorked(coll.createIndex({t: 1}, {expireAfterSeconds: NaN}));
+assert.commandWorked(coll.insert({_id: 0, t: ISODate()}));
+
+// Wait for "TTL indexes require the expire field to be numeric, skipping TTL job" log message.
+checkLog.containsJson(primary, 22542, {ns: coll.getFullName()});
+
+// TTL index should be replicated to the secondary with a NaN 'expireAfterSeconds'.
+const secondary = rst.getSecondary();
+checkLog.containsJson(secondary, 20384, {
+    namespace: coll.getFullName(),
+    properties: (spec) => {
+        jsTestLog('TTL index on secondary: ' + tojson(spec));
+        return isNaN(spec.expireAfterSeconds);
+    }
+});
+
+assert.eq(
+    coll.countDocuments({}), 1, 'ttl index with NaN duration should not remove any documents.');
+
+rst.stopSet();
+})();
diff --git a/src/mongo/db/ttl.cpp b/src/mongo/db/ttl.cpp
index bc76b345f40..8da9e1ee46a 100644
--- a/src/mongo/db/ttl.cpp
+++ b/src/mongo/db/ttl.cpp
@@ -175,12 +175,15 @@ const IndexDescriptor* getValidTTLIndex(OperationContext* opCtx,
     }
 
     BSONElement secondsExpireElt = spec[IndexDescriptor::kExpireAfterSecondsFieldName];
-    if (!secondsExpireElt.isNumber()) {
-        LOGV2_ERROR(22542,
-                    "TTL indexes require the expire field to be numeric, skipping TTL job",
-                    "field"_attr = IndexDescriptor::kExpireAfterSecondsFieldName,
-                    "type"_attr = typeName(secondsExpireElt.type()),
-                    "index"_attr = spec);
+    if (!secondsExpireElt.isNumber() || secondsExpireElt.isNaN()) {
+        LOGV2_ERROR(
+            22542,
+            "TTL indexes require the expire field to be numeric and not a NaN, skipping TTL job",
+            "ns"_attr = collection->ns(),
+            "uuid"_attr = collection->uuid(),
+            "field"_attr = IndexDescriptor::kExpireAfterSecondsFieldName,
+            "type"_attr = typeName(secondsExpireElt.type()),
+            "index"_attr = spec);
         return nullptr;
     }
     return desc;