Fixes #39063 : Don't clear document path when its null representation

src/gui/editorwidgets/qgsexternalresourcewidgetwrapper.h

@@ -75,6 +75,9 @@ class GUI_EXPORT QgsExternalResourceWidgetWrapper : public QgsEditorWidgetWrappe
     QLineEdit *mLineEdit = nullptr;
     QLabel *mLabel = nullptr;
     QgsExternalResourceWidget *mQgsWidget = nullptr;
+
+    friend class TestQgsExternalResourceWidgetWrapper;
+
 };
 
 #endif // QGSEXTERNALRESOURCEWIDGETWRAPPER_H

src/gui/qgsexternalresourcewidget.cpp

@@ -17,6 +17,7 @@
 #include "qgsexternalresourcewidget.h"
 #include "qgspixmaplabel.h"
 #include "qgsproject.h"
+#include "qgsapplication.h"
 
 #include <QDir>
 #include <QGridLayout>
@@ -71,7 +72,7 @@ QgsExternalResourceWidget::QgsExternalResourceWidget( QWidget *parent )
 QVariant QgsExternalResourceWidget::documentPath( QVariant::Type type ) const
 {
   QString path = mFileWidget->filePath();
-  if ( path.isEmpty() )
+  if ( path.isEmpty() || path == QgsApplication::nullRepresentation() )
   {
     return QVariant( type );
   }

src/gui/qgsfilewidget.cpp

@@ -88,14 +88,8 @@ QStringList QgsFileWidget::splitFilePaths( const QString &path )
 
 void QgsFileWidget::setFilePath( QString path )
 {
-  if ( path == QgsApplication::nullRepresentation() )
-  {
-    path.clear();
-  }
-
   //will trigger textEdited slot
   mLineEdit->setValue( path );
-
 }
 
 void QgsFileWidget::setReadOnly( bool readOnly )

tests/src/gui/CMakeLists.txt

@@ -156,3 +156,4 @@ ADD_QGIS_TEST(rasterlayersaveasdialog testqgsrasterlayersaveasdialog.cpp)
 ADD_QGIS_TEST(valuerelationwidgetwrapper testqgsvaluerelationwidgetwrapper.cpp)
 ADD_QGIS_TEST(relationreferencewidget testqgsrelationreferencewidget.cpp)
 ADD_QGIS_TEST(featurelistcombobox testqgsfeaturelistcombobox.cpp)
+ADD_QGIS_TEST(externalresourcewidgetwrapper testqgsexternalresourcewidgetwrapper.cpp)

tests/src/gui/testqgsexternalresourcewidgetwrapper.cpp

@@ -0,0 +1,103 @@
+/***************************************************************************
+                         testqgsexternalresourcewidgetwrapper.cpp
+                         ---------------------------
+    begin                : Oct 2020
+    copyright            : (C) 2020 by Julien Cabieces
+    email                : julien dot cabieces at oslandia dot com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgstest.h"
+#include "qgsvectorlayer.h"
+#include "qgsexternalresourcewidgetwrapper.h"
+#include "qgsexternalresourcewidget.h"
+
+#include <QLineEdit>
+
+/**
+ * @ingroup UnitTests
+ * This is a unit test for the external resource widget wrapper
+ *
+ * \see QgsExternalResourceWidgetWrapper
+ */
+class TestQgsExternalResourceWidgetWrapper : public QObject
+{
+    Q_OBJECT
+  private slots:
+    void initTestCase();// will be called before the first testfunction is executed.
+    void cleanupTestCase();// will be called after the last testfunction was executed.
+    void init();// will be called before each testfunction is executed.
+    void cleanup();// will be called after every testfunction.
+    void test_setNullValues();
+
+  private:
+    std::unique_ptr<QgsVectorLayer> vl;
+};
+
+void TestQgsExternalResourceWidgetWrapper::initTestCase()
+{
+  // Set up the QgsSettings environment
+  QCoreApplication::setOrganizationName( QStringLiteral( "QGIS" ) );
+  QCoreApplication::setOrganizationDomain( QStringLiteral( "qgis.org" ) );
+  QCoreApplication::setApplicationName( QStringLiteral( "QGIS-TEST-EXTERNAL-RESOURCE-WIDGET-WRAPPER" ) );
+
+  QgsApplication::init();
+  QgsApplication::initQgis();
+}
+
+void TestQgsExternalResourceWidgetWrapper::cleanupTestCase()
+{
+  QgsApplication::exitQgis();
+}
+
+void TestQgsExternalResourceWidgetWrapper::init()
+{
+  vl = qgis::make_unique<QgsVectorLayer>( QStringLiteral( "NoGeometry?field=link:string" ),
+                                          QStringLiteral( "myvl" ),
+                                          QLatin1String( "memory" ) );
+}
+
+void TestQgsExternalResourceWidgetWrapper::cleanup()
+{
+}
+
+void TestQgsExternalResourceWidgetWrapper::test_setNullValues()
+{
+  QgsExternalResourceWidgetWrapper ww( vl.get(), 0, nullptr, nullptr );
+  QWidget *widget = ww.createWidget( nullptr );
+  QVERIFY( widget );
+
+  ww.initWidget( widget );
+  QVERIFY( ww.mQgsWidget );
+  QVERIFY( ww.mLineEdit );
+
+  QSignalSpy spy( &ww, &QgsExternalResourceWidgetWrapper::valuesChanged );
+
+  ww.updateValues( QStringLiteral( "test" ) );
+  QCOMPARE( ww.mLineEdit->text(), "test" );
+  QCOMPARE( ww.mQgsWidget->documentPath(), QStringLiteral( "test" ) );
+  QCOMPARE( spy.count(), 1 );
+
+  ww.updateValues( QVariant() );
+  QCOMPARE( ww.mLineEdit->text(), QgsApplication::nullRepresentation() );
+  QCOMPARE( ww.mQgsWidget->documentPath(), QVariant( QVariant::String ) );
+  QCOMPARE( spy.count(), 2 );
+
+  ww.updateValues( QgsApplication::nullRepresentation() );
+  QCOMPARE( ww.mLineEdit->text(), QgsApplication::nullRepresentation() );
+  QCOMPARE( ww.mQgsWidget->documentPath(), QVariant( QVariant::String ) );
+  QCOMPARE( spy.count(), 2 );
+
+  delete widget;
+}
+
+QGSTEST_MAIN( TestQgsExternalResourceWidgetWrapper )
+#include "testqgsexternalresourcewidgetwrapper.moc"