From 66a06427f9ad21da7e768175e8e683cc08a317c7 Mon Sep 17 00:00:00 2001
From: Mat Sutcliffe <oktal3700@gmail.com>
Date: Thu, 3 Jan 2019 02:01:09 +0000
Subject: [PATCH] Ref T495 Using QThreadStorage because thread_local caused a
 static destruction order fiasco.

---
 src/blackmisc/statusmessage.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/blackmisc/statusmessage.cpp b/src/blackmisc/statusmessage.cpp
index d6c039dbc..9fc405bb0 100644
--- a/src/blackmisc/statusmessage.cpp
+++ b/src/blackmisc/statusmessage.cpp
@@ -18,11 +18,14 @@
 
 #include <QMetaEnum>
 #include <QStringBuilder>
+#include <QThreadStorage>
 
 namespace BlackMisc
 {
     namespace Private
     {
+        QThreadStorage<QString> t_tempBuffer; // thread_local would be destroyed before function-scope statics, see T495
+
         QString arg(QStringView format, const QStringList &args)
         {
             if (format.isEmpty())
@@ -30,7 +33,7 @@ namespace BlackMisc
                 return args.join(u' ');
             }
 
-            thread_local QString temp;
+            QString &temp = t_tempBuffer.localData();
             temp.resize(0); // unlike clear(), resize(0) doesn't release the capacity if there are no implicitly shared copies
 
             for (auto it = format.begin(); ; )