Fix discarded QFile::open() results

Also validate return value of QIODevice::open() and QBuffer::open()
calls.

Pick-to: 6.8 6.9
Change-Id: I71ea58f62cab5aafdd2b4eca217394dddf0033cd
Reviewed-by: Michal Klocek <[email protected]>
Reviewed-by: Moss Heim <[email protected]>

1 files changed, 4 insertions, 1 deletions

diff --git a/tests/auto/widgets/qwebenginescript/tst_qwebenginescript.cpp b/tests/auto/widgets/qwebenginescript/tst_qwebenginescript.cpp
index 1a4ee9c4b..1dfa94565 100644
--- a/tests/auto/widgets/qwebenginescript/tst_qwebenginescript.cpp
+++ b/tests/auto/widgets/qwebenginescript/tst_qwebenginescript.cpp
@@ -359,7 +359,10 @@ private:
 static QString readFile(const QString &path)
 {
     QFile file(path);
-    file.open(QFile::ReadOnly);
+    if (!file.open(QFile::ReadOnly)) {
+        qWarning("Failed to read file %s: %s", qPrintable(path), qPrintable(file.errorString()));
+        return QString();
+    }
     QByteArray contents = file.readAll();
     file.close();
     return contents;