Fix layout picture item test (alternate fix to #31382) (#31383)

* Fix layout picture item test (alternate fix to #31382)
* doxygen: add pointer to QgsProperty::value() to QgsAbstractPropertyCollection::value()

python/core/auto_generated/qgspropertycollection.sip.in

@@ -89,6 +89,8 @@ Returns a matching property from the collection, if one exists.
     virtual QVariant value( int key, const QgsExpressionContext &context, const QVariant &defaultValue = QVariant() ) const = 0;
 %Docstring
 Returns the calculated value of the property with the specified key from within the collection.
+If you need the validity of the value (like ok provided from the
+valueAs* variants) refer to the property() and :py:func:`QgsProperty.value()`
 
 :param key: integer key for property to return. The intended use case is that a context specific enum is cast to
             int and used for the key value.

src/core/layout/qgslayoutitempicture.cpp

@@ -342,8 +342,10 @@ void QgsLayoutItemPicture::refreshPicture( const QgsExpressionContext *context )
   mHasExpressionError = false;
   if ( mDataDefinedProperties.isActive( QgsLayoutObject::PictureSource ) )
   {
-    source = mDataDefinedProperties.value( QgsLayoutObject::PictureSource, *evalContext, QVariant( source ) );
+    bool ok = false;
-    if ( !source.canConvert( QMetaType::QString ) )
+    const QgsProperty &sourceProperty = mDataDefinedProperties.property( QgsLayoutObject::PictureSource );
+    source = sourceProperty.value( *evalContext, QVariant( source ), &ok );
+    if ( !ok || !source.canConvert( QMetaType::QString ) )
     {
       mHasExpressionError = true;
       source = QString();

src/core/qgspropertycollection.h

@@ -101,6 +101,8 @@ class CORE_EXPORT QgsAbstractPropertyCollection
 
     /**
      * Returns the calculated value of the property with the specified key from within the collection.
+     * If you need the validity of the value (like ok provided from the
+     * valueAs* variants) refer to the property() and QgsProperty::value()
      * \param key integer key for property to return. The intended use case is that a context specific enum is cast to
      * int and used for the key value.
      * \param context expression context to evaluate property against

tests/src/core/CMakeLists.txt

@@ -60,7 +60,8 @@ MACRO (ADD_QGIS_TEST TESTSRC)
   STRING(REPLACE "qgs" "" TESTNAME ${TESTNAME})
   STRING(REPLACE ".cpp" "" TESTNAME ${TESTNAME})
   SET (TESTNAME  "qgis_${TESTNAME}test")
-  ADD_EXECUTABLE(${TESTNAME} ${TESTSRC} ${util_SRCS})
+  QT5_ADD_RESOURCES(IMAGES_RCC_SRC ${CMAKE_SOURCE_DIR}/images/images.qrc)
+  ADD_EXECUTABLE(${TESTNAME} ${TESTSRC} ${util_SRCS} ${IMAGES_RCC_SRC})
   SET_TARGET_PROPERTIES(${TESTNAME} PROPERTIES AUTOMOC TRUE)
   TARGET_LINK_LIBRARIES(${TESTNAME}
     ${Qt5Core_LIBRARIES}

tests/src/core/testqgslayoutpicture.cpp

@@ -76,6 +76,7 @@ void TestQgsLayoutPicture::initTestCase()
 {
   QgsApplication::init();
   QgsApplication::initQgis();
+  QgsApplication::showSettings();
 
   mPngImage = QStringLiteral( TEST_DATA_DIR ) + "/sample_image.png";
   mSvgImage = QStringLiteral( TEST_DATA_DIR ) + "/sample_svg.svg";