Verify returns from QXmlTestLogger's xmlQuote() and xmlCdata()

Using partially-converted text would lead to invalid XML, so don't use
the buffer contents if the return is zero. As a result,
QTestJUnitStreamer::formatEnd() needs to return some indication of
whether *it* succeeded, so change it to forward their int returns;
and, as it's in fact only used internally by the streamer, make it
private.

Make these functions [[nodiscard]] so that further uses of them will
be discouraged from ignoring the possibility of failure. Make the
public versions return bool so that they can correctly succeed on
empty input. Assert various conditions we can infer to save work we
don't need to do.

Change-Id: I899bad23d1dfbd05fc725de269def4ce213dbc5a
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

1 files changed, 13 insertions, 10 deletions

diff --git a/src/testlib/qtestjunitstreamer.cpp b/src/testlib/qtestjunitstreamer.cpp
index 72ab7d1534..3e67e5c4bf 100644
--- a/src/testlib/qtestjunitstreamer.cpp
+++ b/src/testlib/qtestjunitstreamer.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2016 The Qt Company Ltd.
+** Copyright (C) 2021 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtTest module of the Qt Toolkit.
@@ -106,23 +106,26 @@ void QTestJUnitStreamer::formatEnd(const QTestElement *element, QTestCharBuffer
     QTest::qt_asprintf(formatted, "%s</%s>\n", indent, element->elementName());
 }
 
-void QTestJUnitStreamer::formatAttributes(const QTestElement* element, const QTestElementAttribute *attribute, QTestCharBuffer *formatted) const
+bool QTestJUnitStreamer::formatAttributes(const QTestElement* element,
+                                          const QTestElementAttribute *attribute,
+                                          QTestCharBuffer *formatted) const
 {
     if (!attribute || !formatted )
-        return;
+        return false;
 
     QTest::AttributeIndex attrindex = attribute->index();
 
     if (element && element->elementType() == QTest::LET_Text) {
         QTEST_ASSERT(attrindex == QTest::AI_Value);
-        QXmlTestLogger::xmlCdata(formatted, attribute->value());
-        return;
+        return QXmlTestLogger::xmlCdata(formatted, attribute->value());
     }
 
     QTestCharBuffer quotedValue;
-    QXmlTestLogger::xmlQuote(&quotedValue, attribute->value());
-    QTest::qt_asprintf(formatted, " %s=\"%s\"",
-        attribute->name(), quotedValue.constData());
+    if (QXmlTestLogger::xmlQuote(&quotedValue, attribute->value())) {
+        return QTest::qt_asprintf(formatted, " %s=\"%s\"",
+                                  attribute->name(), quotedValue.constData()) != 0;
+    }
+    return false;
 }
 
 void QTestJUnitStreamer::formatAfterAttributes(const QTestElement *element, QTestCharBuffer *formatted) const
@@ -176,8 +179,8 @@ void QTestJUnitStreamer::outputElementAttributes(const QTestElement* element, co
     QTestCharBuffer buf;
 
     for (auto *attribute : attributes) {
-        formatAttributes(element, attribute, &buf);
-        outputString(buf.data());
+        if (formatAttributes(element, attribute, &buf))
+            outputString(buf.data());
     }
 }