Fix crash when using QLockFile in a global destructor

(for instance any global object which writes out to a config file in the
destructor). If the global cache isn't available anymore, don't use it.

Change-Id: I851a6e394d0b073aebf3ffd88b1966d424bfb92e
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/corelib/io/qlockfile_unix.cpp b/src/corelib/io/qlockfile_unix.cpp
index 623968b869..bcef84206e 100644
--- a/src/corelib/io/qlockfile_unix.cpp
+++ b/src/corelib/io/qlockfile_unix.cpp
@@ -136,6 +136,8 @@ static QBasicMutex fcntlLock;
 static bool fcntlWorksAfterFlock(const QString &fn)
 {
     QMutexLocker lock(&fcntlLock);
+    if (fcntlOK.isDestroyed())
+        return QLockFilePrivate::checkFcntlWorksAfterFlock(fn);
     bool *worksPtr = fcntlOK->object(fn);
     if (!worksPtr) {
         worksPtr = new bool(QLockFilePrivate::checkFcntlWorksAfterFlock(fn));