diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 03d26e24d2c..d9a2ce5e40d 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -6147,6 +6147,25 @@ GetWALInsertionTimeLine(void)
 	return XLogCtl->InsertTimeLineID;
 }
 
+/*
+ * GetWALInsertionTimeLineIfSet -- If the system is not in recovery, returns
+ * the WAL insertion timeline; else, returns 0. Wherever possible, use
+ * GetWALInsertionTimeLine() instead, since it's cheaper. Note that this
+ * function decides recovery has ended as soon as the insert TLI is set, which
+ * happens before we set XLogCtl->SharedRecoveryState to RECOVERY_STATE_DONE.
+ */
+TimeLineID
+GetWALInsertionTimeLineIfSet(void)
+{
+	TimeLineID	insertTLI;
+
+	SpinLockAcquire(&XLogCtl->info_lck);
+	insertTLI = XLogCtl->InsertTimeLineID;
+	SpinLockRelease(&XLogCtl->info_lck);
+
+	return insertTLI;
+}
+
 /*
  * GetLastImportantRecPtr -- Returns the LSN of the last important record
  * inserted. All records not explicitly marked as unimportant are considered
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 6fd5b3dfa66..287b8af4350 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -245,6 +245,7 @@ extern XLogRecPtr GetRedoRecPtr(void);
 extern XLogRecPtr GetInsertRecPtr(void);
 extern XLogRecPtr GetFlushRecPtr(TimeLineID *insertTLI);
 extern TimeLineID GetWALInsertionTimeLine(void);
+extern TimeLineID GetWALInsertionTimeLineIfSet(void);
 extern XLogRecPtr GetLastImportantRecPtr(void);
 
 extern void SetWalWriterSleeping(bool sleeping);