quickvectorimage: report a failed parse for the item generator

For the item generator, the return value of QQuickGenerator::generate()
is discarded and only errorState() is checked. This does not cover a
document that fails to parse. A broken file therefore takes the success
branch, and status() reports Null instead of Error.

Report the failure through errorState(), and derive Error in status()
from a source that produced no item.

Task-number: QTBUG-149650
Change-Id: Iff9271af651476b8aa179d74887234ad47cf45be
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

3 files changed, 14 insertions, 8 deletions

diff --git a/src/quickvectorimage/generator/qquickgenerator.cpp b/src/quickvectorimage/generator/qquickgenerator.cpp
index 26e5a37807..8b023a89e3 100644
--- a/src/quickvectorimage/generator/qquickgenerator.cpp
+++ b/src/quickvectorimage/generator/qquickgenerator.cpp
@@ -49,7 +49,9 @@ bool QQuickGenerator::generate()
 {
     m_errorState = QQuickVectorImageGenerator::NoError;
     QSvgVisitorImpl loader(m_source, this, m_flags.testFlag(QQuickVectorImageGenerator::AssumeTrustedSource));
-    return loader.doTraversal();
+    if (!loader.doTraversal())
+        m_errorState = QQuickVectorImageGenerator::LoadFailed;
+    return m_errorState == QQuickVectorImageGenerator::NoError;
 }
 
 void QQuickGenerator::optimizePaths(const PathNodeInfo &info, const QRectF &overrideBoundingRect)
diff --git a/src/quickvectorimage/qquickvectorimage.cpp b/src/quickvectorimage/qquickvectorimage.cpp
index cc8d6a068f..fc4e34f0f2 100644
--- a/src/quickvectorimage/qquickvectorimage.cpp
+++ b/src/quickvectorimage/qquickvectorimage.cpp
@@ -152,11 +152,12 @@ void QQuickVectorImagePrivate::loadFile()
         if (!generatedWithPlugin)
             gen.generate();
 
-        if (gen.errorState() == QQuickVectorImageGenerator::NoError) {
-            pendingRootItem = gen.takeRootItem();
+        if (gen.errorState() != QQuickVectorImageGenerator::NoError) {
+            qCWarning(lcQuickVectorImage)
+                    << "QQuickItemGenerator: failed to generate" << imageSource
+                    << "(errorState:" << gen.errorState() << ")";
         } else {
-            qCWarning(lcQuickVectorImage) << "QQuickItemGenerator: failed to generate" << imageSource
-                                          << "(errorState:" << gen.errorState() << ")";
+            pendingRootItem = gen.takeRootItem();
         }
         q->updateItem();
     }
@@ -544,10 +545,12 @@ QQuickVectorImage::Status QQuickVectorImage::status() const
 {
     Q_D(const QQuickVectorImage);
     if (d->incubator == nullptr) {
-        if (d->rootItem == nullptr)
+        if (d->rootItem != nullptr)
+            return Status::Ready;
+        else if (!isComponentComplete() || d->imageSource.isEmpty())
             return Status::Null;
         else
-            return Status::Ready;
+            return Status::Error;
     }
 
     switch (d->incubator->status()) {
diff --git a/src/quickvectorimage/qquickvectorimageglobal_p.h b/src/quickvectorimage/qquickvectorimageglobal_p.h
index 5cb2cada2f..3bdd9d925c 100644
--- a/src/quickvectorimage/qquickvectorimageglobal_p.h
+++ b/src/quickvectorimage/qquickvectorimageglobal_p.h
@@ -43,7 +43,8 @@ namespace QQuickVectorImageGenerator
 
     enum ErrorState {
         NoError = 0,
-        SanityLimitsExceeded
+        SanityLimitsExceeded,
+        LoadFailed
     };
 }