From 7441a0ecba355d1c7b8c21e5d37df4e0d0b212da Mon Sep 17 00:00:00 2001
From: Maysam Yabandeh <myabandeh@fb.com>
Date: Wed, 3 Apr 2019 15:43:34 -0700
Subject: [PATCH] WriteUnPrepared: fix ubsan complaint (#5148)

Summary:
Ubsna complains that in initialization of WriteUnpreparedTxnReadCallback the method of the child class is used before the parent class is constructed. The patch fixes that by making the aforementioned method static.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/5148

Differential Revision: D14760098

Pulled By: maysamyabandeh

fbshipit-source-id: cf19b7c1fdb5de0a54e62c1deebe09a0fa048ded
---
 utilities/transactions/write_unprepared_txn.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/utilities/transactions/write_unprepared_txn.h b/utilities/transactions/write_unprepared_txn.h
index 4a00406d7..68567eb6e 100644
--- a/utilities/transactions/write_unprepared_txn.h
+++ b/utilities/transactions/write_unprepared_txn.h
@@ -42,14 +42,15 @@ class WriteUnpreparedTxnReadCallback : public ReadCallback {
 
   // TODO(myabandeh): override Refresh when Iterator::Refresh is supported
  private:
-  SequenceNumber CalcMaxVisibleSeq(WriteUnpreparedTxn* txn,
-                                   SequenceNumber snapshot_seq) {
+  static SequenceNumber CalcMaxVisibleSeq(WriteUnpreparedTxn* txn,
+                                          SequenceNumber snapshot_seq) {
     SequenceNumber max_unprepared = CalcMaxUnpreparedSequenceNumber(txn);
     assert(snapshot_seq < max_unprepared || max_unprepared == 0 ||
            snapshot_seq == kMaxSequenceNumber);
     return std::max(max_unprepared, snapshot_seq);
   }
-  SequenceNumber CalcMaxUnpreparedSequenceNumber(WriteUnpreparedTxn* txn);
+  static SequenceNumber CalcMaxUnpreparedSequenceNumber(
+      WriteUnpreparedTxn* txn);
   WritePreparedTxnDB* db_;
   WriteUnpreparedTxn* txn_;
   SequenceNumber wup_snapshot_;