tdf#105017 Crash when click a "New Theme..." in Gallery on detached SideBar

caused by VclPtr fixes which meant instead of the dialog staying in an
always-zero ref-count state, it went up to a ref-count of 1, then down
to zero, which triggered a delete before the dialog had finished
displaying.

And revert my fix in commit 0c1cd678
which just worked around the underlying problem

Change-Id: Icb35535dd06a2d1db1016d00d106760847d87430

svx/source/gallery2/galbrws1.cxx

@@ -148,6 +148,7 @@ GalleryBrowser1::~GalleryBrowser1()
 void GalleryBrowser1::dispose()
 {
     EndListening( *mpGallery );
+    mpThemePropertiesDialog.clear();
     mpThemes.disposeAndClear();
     delete mpExchangeData;
     mpExchangeData = nullptr;
@@ -265,24 +266,24 @@ void GalleryBrowser1::ImplGalleryThemeProperties( const OUString & rThemeName, b
 
     SvxAbstractDialogFactory* pFact = SvxAbstractDialogFactory::Create();
     assert(pFact && "Got no AbstractDialogFactory!");
-    VclPtr<VclAbstractDialog2> pThemeProps = pFact->CreateGalleryThemePropertiesDialog( mpExchangeData, mpThemePropsDlgItemSet );
-    assert(pThemeProps && "Got no GalleryThemePropertiesDialog!");
+    mpThemePropertiesDialog = pFact->CreateGalleryThemePropertiesDialog( mpExchangeData, mpThemePropsDlgItemSet );
+    assert(mpThemePropertiesDialog && "Got no GalleryThemePropertiesDialog!");
 
     if ( bCreateNew )
     {
-        pThemeProps->StartExecuteModal(
+        mpThemePropertiesDialog->StartExecuteModal(
             LINK( this, GalleryBrowser1, EndNewThemePropertiesDlgHdl ) );
     }
     else
     {
-        pThemeProps->StartExecuteModal(
+        mpThemePropertiesDialog->StartExecuteModal(
             LINK( this, GalleryBrowser1, EndThemePropertiesDlgHdl ) );
     }
 }
 
-void GalleryBrowser1::ImplEndGalleryThemeProperties(Dialog* pDialog, bool bCreateNew)
+void GalleryBrowser1::ImplEndGalleryThemeProperties(Dialog* /*pDialog*/, bool bCreateNew)
 {
-    long nRet = pDialog->GetResult();
+    long nRet = mpThemePropertiesDialog->GetResult();
 
     if( nRet == RET_OK )
     {
@@ -319,23 +320,22 @@ void GalleryBrowser1::ImplEndGalleryThemeProperties(Dialog* pDialog, bool bCreat
     }
 
     // destroy mpThemeProps asynchronously
-    Application::PostUserEvent( LINK( this, GalleryBrowser1, DestroyThemePropertiesDlgHdl ), pDialog, true );
+    Application::PostUserEvent( LINK( this, GalleryBrowser1, DestroyThemePropertiesDlgHdl ), nullptr, true );
 }
 
-IMPL_LINK( GalleryBrowser1, EndNewThemePropertiesDlgHdl, Dialog&, rDialog, void )
+IMPL_LINK( GalleryBrowser1, EndNewThemePropertiesDlgHdl, Dialog&, /*rDialog*/, void )
 {
-    ImplEndGalleryThemeProperties(&rDialog, true);
+    ImplEndGalleryThemeProperties(nullptr, true);
 }
 
-IMPL_LINK( GalleryBrowser1, EndThemePropertiesDlgHdl, Dialog&, rDialog, void )
+IMPL_LINK( GalleryBrowser1, EndThemePropertiesDlgHdl, Dialog&, /*rDialog*/, void )
 {
-    ImplEndGalleryThemeProperties(&rDialog, false);
+    ImplEndGalleryThemeProperties(nullptr, false);
 }
 
-IMPL_LINK( GalleryBrowser1, DestroyThemePropertiesDlgHdl, void*, p, void )
+IMPL_LINK( GalleryBrowser1, DestroyThemePropertiesDlgHdl, void*, /*p*/, void )
 {
-    VclPtr<VclAbstractDialog2> pDialog = static_cast<VclAbstractDialog2*>(p);
-    pDialog.disposeAndClear();
+    mpThemePropertiesDialog.disposeAndClear();
     delete mpThemePropsDlgItemSet;
     mpThemePropsDlgItemSet = nullptr;
 }

svx/source/gallery2/galbrws1.hxx

@@ -76,8 +76,9 @@ class GalleryBrowser1 : public Control, public SfxListener
 
 private:
 
-    VclPtr<GalleryButton>   maNewTheme;
+    VclPtr<GalleryButton>        maNewTheme;
     VclPtr<GalleryThemeListBox>  mpThemes;
+    VclPtr<VclAbstractDialog2>   mpThemePropertiesDialog; // to keep it alive during execution
     Gallery*                mpGallery;
     ExchangeData*           mpExchangeData;
     SfxItemSet*             mpThemePropsDlgItemSet;

vcl/source/window/dialog.cxx

@@ -1037,7 +1037,7 @@ void Dialog::SetModalInputMode( bool bModal )
         // Disable the prev Modal Dialog, because our dialog must close at first,
         // before the other dialog can be closed (because the other dialog
         // is on stack since our dialog returns)
-        if ( mpPrevExecuteDlg && !mpPrevExecuteDlg->isDisposed() && !mpPrevExecuteDlg->IsWindowOrChild( this, true ) )
+        if ( mpPrevExecuteDlg && !mpPrevExecuteDlg->IsWindowOrChild( this, true ) )
             mpPrevExecuteDlg->EnableInput( false, this );
 
         // determine next overlap dialog parent