[TD]fix fail on object deleted during dialog (#9626)

src/Mod/TechDraw/Gui/TaskBalloon.cpp

@@ -31,6 +31,7 @@
 #include <Gui/BitmapFactory.h>
 #include <Gui/Command.h>
 #include <Gui/Document.h>
+#include <Gui/Control.h>
 
 #include "TaskBalloon.h"
 #include "ui_TaskBalloon.h"
@@ -49,6 +50,9 @@ TaskBalloon::TaskBalloon(QGIViewBalloon *parent, ViewProviderBalloon *balloonVP)
     int i = 0;
     m_parent = parent;
     m_balloonVP = balloonVP;
+    m_guiDocument = balloonVP->getDocument();
+    m_appDocument = parent->getBalloonFeat()->getDocument();
+    m_balloonName = parent->getBalloonFeat()->getNameInDocument();
 
     ui->setupUi(this);
 
@@ -98,6 +102,7 @@ TaskBalloon::TaskBalloon(QGIViewBalloon *parent, ViewProviderBalloon *balloonVP)
     connect(ui->comboLineVisible, qOverload<int>(&QComboBox::currentIndexChanged), this, &TaskBalloon::onLineVisibleChanged);
     connect(ui->qsbLineWidth, qOverload<double>(&QuantitySpinBox::valueChanged), this, &TaskBalloon::onLineWidthChanged);
     connect(ui->qsbKinkLength, qOverload<double>(&QuantitySpinBox::valueChanged), this, &TaskBalloon::onKinkLengthChanged);
+
 }
 
 TaskBalloon::~TaskBalloon()
@@ -106,22 +111,44 @@ TaskBalloon::~TaskBalloon()
 
 bool TaskBalloon::accept()
 {
-    Gui::Document* doc = m_balloonVP->getDocument();
-    m_balloonVP->getObject()->purgeTouched();
-    doc->commitCommand();
-    doc->resetEdit();
+    // re issue #9626 if the balloon is deleted while the task dialog is in progress we will fail
+    // trying to access the feature object or the viewprovider.  This should be prevented by
+    // change to ViewProviderBalloon
+    // see also reject()
+    App::DocumentObject* balloonFeature = m_appDocument->getObject(m_balloonName.c_str());
+    if(balloonFeature) {
+        // an object with our name still exists in the document
+        balloonFeature->purgeTouched();
+        m_guiDocument->commitCommand();
+    } else {
+        // see comment in reject(). this may not do what we want.
+        Gui::Command::abortCommand();
+    }
+
+    m_guiDocument->resetEdit();
 
     return true;
 }
 
 bool TaskBalloon::reject()
 {
-    Gui::Document* doc = m_balloonVP->getDocument();
-    doc->abortCommand();
-    recomputeFeature();
-    m_parent->updateView(true);
-    m_balloonVP->getObject()->purgeTouched();
-    doc->resetEdit();
+    // re issue #9626 - if the balloon is deleted while the dialog is in progress
+    // the delete transaction is still active and ?locked? so our "abortCommand"
+    // doesn't work properly and a pending transaction is still in place.  This
+    // causes a warning message from App::AutoTransaction (??) that can't be
+    // cleared.  Even closing the document will not clear the warning.
+    // A change to ViewProviderBalloon::onDelete should prevent this from
+    // happening from the Gui.  It is possible(?) that the balloon could be
+    // deleted by a script.
+    m_guiDocument->abortCommand();
+    App::DocumentObject* balloonFeature = m_appDocument->getObject(m_balloonName.c_str());
+    if(balloonFeature) {
+        // an object with our name still exists in the document
+        balloonFeature->recomputeFeature();
+        balloonFeature->purgeTouched();
+    }
+    m_guiDocument->resetEdit();
+    Gui::Command::updateActive();
 
     return true;
 }

src/Mod/TechDraw/Gui/TaskBalloon.h

@@ -28,6 +28,14 @@
 #include <Gui/TaskView/TaskView.h>
 #include <Mod/TechDraw/TechDrawGlobal.h>
 
+namespace Gui
+{
+class Document;
+}
+namespace App
+{
+class Document;
+}
 
 namespace TechDrawGui
 {
@@ -64,6 +72,10 @@ private:
     std::unique_ptr<Ui_TaskBalloon> ui;
     QGIViewBalloon *m_parent;
     ViewProviderBalloon* m_balloonVP;
+
+    std::string m_balloonName;
+    App::Document* m_appDocument;
+    Gui::Document* m_guiDocument;
 };
 
 class TaskDlgBalloon : public Gui::TaskView::TaskDialog

src/Mod/TechDraw/Gui/ViewProviderBalloon.cpp

@@ -162,5 +162,6 @@ bool ViewProviderBalloon::canDelete(App::DocumentObject *obj) const
     // deletions of a balloon object doesn't destroy anything
     // thus we can pass this action
     Q_UNUSED(obj)
+    Base::Console().Message("VPB::canDelete()\n");
     return true;
 }