From f2102e1f829d216591a5f49819847c05383305ae Mon Sep 17 00:00:00 2001
From: Timothy Pearson <kb9vqf@pearsoncomputing.net>
Date: Mon, 10 Jun 2013 13:20:17 -0500
Subject: Fix incorrect thread termination handling when thread count is
 greater than two This resolves Bug 1521 Make double free or delete of QString
 objects more obvious

---
 src/tools/qstring.cpp | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

(limited to 'src/tools')

diff --git a/src/tools/qstring.cpp b/src/tools/qstring.cpp
index 0630cd3..251637d 100644
--- a/src/tools/qstring.cpp
+++ b/src/tools/qstring.cpp
@@ -1071,13 +1071,20 @@ QStringData::QStringData(QChar *u, uint l, uint m) : QShared(),
 }
 
 QStringData::~QStringData() {
-	if ( unicode ) delete[] ((char*)unicode);
+	if ( unicode ) {
+		delete[] ((char*)unicode);
+	}
 	if ( ascii && security_unpaged ) {
 		munlock(ascii, LINUX_MEMLOCK_LIMIT_BYTES);
 	}
-	if ( ascii ) delete[] ascii;
+	if ( ascii ) {
+		delete[] ascii;
+	}
 #ifdef QT_THREAD_SUPPORT
-	if ( mutex ) delete mutex;
+	if ( mutex ) {
+		delete mutex;
+		mutex = NULL;
+	}
 #endif // QT_THREAD_SUPPORT
 }
 
@@ -1675,6 +1682,13 @@ QString::QString( QStringData* dd, bool /* dummy */ ) {
 
 QString::~QString()
 {
+#if defined(QT_CHECK_RANGE)
+	if (!d) {
+		qWarning( "QString::~QString: Double free or delete detected!" );
+		return;
+	}
+#endif
+
 #ifdef QT_THREAD_SUPPORT
 	d->mutex->lock();
 #endif // QT_THREAD_SUPPORT
@@ -1684,6 +1698,7 @@ QString::~QString()
 			d->mutex->unlock();
 #endif // QT_THREAD_SUPPORT
 			d->deleteSelf();
+			d = NULL;
 		}
 		else {
 #ifdef QT_THREAD_SUPPORT
-- 
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