SERVER-31664 Fix use after free of OperationContext by ExpressionDate*

Addresses the case where a time zone expression lives within a collection
validator as part of a $expr expression. In this case, the Expression
will outlive the OperationContext it was created under.

2 files changed, 2 insertions, 2 deletions

diff --git a/src/mongo/db/query/datetime/date_time_support.cpp b/src/mongo/db/query/datetime/date_time_support.cpp
index fc24dd22206..2b6cb8ec078 100644
--- a/src/mongo/db/query/datetime/date_time_support.cpp
+++ b/src/mongo/db/query/datetime/date_time_support.cpp
@@ -68,7 +68,6 @@ long long seconds(Date_t date) {
 }  // namespace
 
 const TimeZoneDatabase* TimeZoneDatabase::get(ServiceContext* serviceContext) {
-    invariant(getTimeZoneDatabase(serviceContext));
     return getTimeZoneDatabase(serviceContext).get();
 }
 
diff --git a/src/mongo/db/query/datetime/date_time_support.h b/src/mongo/db/query/datetime/date_time_support.h
index 9973a198939..9d5b3188abc 100644
--- a/src/mongo/db/query/datetime/date_time_support.h
+++ b/src/mongo/db/query/datetime/date_time_support.h
@@ -346,7 +346,8 @@ public:
     };
 
     /**
-     * Returns the TimeZoneDatabase object associated with the specified service context.
+     * Returns the TimeZoneDatabase object associated with the specified service context or nullptr
+     * if none exists.
      */
     static const TimeZoneDatabase* get(ServiceContext* serviceContext);