Do polling based file watching for NFS on linux, resolves keepassxreb…

…oot#1799

src/gui/DatabaseWidget.cpp

@@ -58,6 +58,10 @@
 
 #include "config-keepassx.h"
 
+#ifdef Q_OS_LINUX
+#include <sys/vfs.h>
+#endif
+
 #ifdef WITH_XC_SSHAGENT
 #include "sshagent/SSHAgent.h"
 #endif
@@ -1173,6 +1177,21 @@ void DatabaseWidget::updateFilePath(const QString& filePath)
         m_fileWatcher.removePath(m_filePath);
     }
 
+#if defined(Q_OS_LINUX)
+    struct statfs statfsBuf;
+    bool forcePolling = false;
+    const auto NFS_SUPER_MAGIC = 0x6969;
+
+    if (!statfs(filePath.toLocal8Bit().constData(), &statfsBuf)) {
+        forcePolling = (statfsBuf.f_type == NFS_SUPER_MAGIC);
+    } else {
+        // if we can't get the fs type let's fall back to polling
+        forcePolling = true;
+    }
+    auto objectName = forcePolling ? QLatin1String("_qt_autotest_force_engine_poller") : QLatin1String("");
+    m_fileWatcher.setObjectName(objectName);
+#endif
+
     m_fileWatcher.addPath(filePath);
     m_filePath = filePath;
     m_db->setFilePath(filePath);