From 3d1362757be1c8ac73f2f7937ac0dcd696ca6f46 Mon Sep 17 00:00:00 2001
From: John Ralls <jralls@ceridwen.us>
Date: Wed, 28 Nov 2018 15:37:25 +0900
Subject: [PATCH] Prevent potential undefined behavior by shifting by a wrapped
 uint.

Found by clang static analyzer.
---
 libgnucash/engine/gnc-int128.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libgnucash/engine/gnc-int128.cpp b/libgnucash/engine/gnc-int128.cpp
index 3da9a9fade..d4c25bea17 100644
--- a/libgnucash/engine/gnc-int128.cpp
+++ b/libgnucash/engine/gnc-int128.cpp
@@ -374,6 +374,8 @@ GncInt128&
 GncInt128::operator<<= (unsigned int i) noexcept
 {
     auto flags = get_flags(m_hi);
+    if (i == 0)
+        return *this;
     if (i > maxbits)
     {
         flags &= 0xfe;