check GetShell

it might return nullptr

Change-Id: I65b43d69f4757b6c331582ca2e256cdea01377af
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/148194
Tested-by: Jenkins
Tested-by: Caolán McNamara <caolanm@redhat.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
(cherry picked from commit 9eb083ab732512c3ab64007c3be1c54be97172f6)
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/148231

4 files changed, 28 insertions, 16 deletions

diff --git a/sfx2/source/control/ctrlitem.cxx b/sfx2/source/control/ctrlitem.cxx
index 28edfec666de..df7ba128659d 100644
--- a/sfx2/source/control/ctrlitem.cxx
+++ b/sfx2/source/control/ctrlitem.cxx
@@ -325,15 +325,17 @@ MapUnit SfxControllerItem::GetCoreMetric() const
         const SfxSlotServer *pServer = pCache->GetSlotServer( *pDispat );
         if ( pServer )
         {
-            SfxShell *pSh = pDispat->GetShell( pServer->GetShellLevel() );
-            SfxItemPool &rPool = pSh->GetPool();
-            sal_uInt16 nWhich = rPool.GetWhich( nId );
+            if (SfxShell *pSh = pDispat->GetShell( pServer->GetShellLevel() ))
+            {
+                SfxItemPool &rPool = pSh->GetPool();
+                sal_uInt16 nWhich = rPool.GetWhich( nId );
 
-            // invalidate slot and its message|slot server as 'global' information
-            // about the validated message|slot server is not made available
-            pCache->Invalidate( true );
+                // invalidate slot and its message|slot server as 'global' information
+                // about the validated message|slot server is not made available
+                pCache->Invalidate( true );
 
-            return rPool.GetMetric( nWhich );
+                return rPool.GetMetric( nWhich );
+            }
         }
     }
 
diff --git a/sfx2/source/control/dispatch.cxx b/sfx2/source/control/dispatch.cxx
index 17edf97cc16d..9d85075de433 100644
--- a/sfx2/source/control/dispatch.cxx
+++ b/sfx2/source/control/dispatch.cxx
@@ -774,11 +774,13 @@ const SfxSlot* SfxDispatcher::GetSlot( const OUString& rCommand )
 
     for ( sal_uInt16 i = 0; i < nTotCount; ++i )
     {
-        SfxShell *pObjShell = GetShell(i);
-        SfxInterface *pIFace = pObjShell->GetInterface();
-        const SfxSlot *pSlot = pIFace->GetSlot( rCommand );
-        if ( pSlot )
-            return pSlot;
+        if (SfxShell *pObjShell = GetShell(i))
+        {
+            SfxInterface *pIFace = pObjShell->GetInterface();
+            const SfxSlot *pSlot = pIFace->GetSlot( rCommand );
+            if ( pSlot )
+                return pSlot;
+        }
     }
 
     return nullptr;
@@ -1152,6 +1154,9 @@ void SfxDispatcher::Update_Impl_( bool bUIActive, bool bIsMDIApp, bool bIsIPOwne
     for ( sal_uInt16 nShell = nTotCount; nShell > 0; --nShell )
     {
         SfxShell *pShell = GetShell( nShell-1 );
+        if (!pShell)
+            continue;
+
         SfxInterface *pIFace = pShell->GetInterface();
 
         // don't consider shells if "Hidden" or "Quiet"
@@ -1567,6 +1572,9 @@ bool SfxDispatcher::FindServer_(sal_uInt16 nSlot, SfxSlotServer& rServer)
     for ( sal_uInt16 i = nFirstShell; i < nTotCount; ++i )
     {
         SfxShell *pObjShell = GetShell(i);
+        if (!pObjShell)
+            continue;
+
         SfxInterface *pIFace = pObjShell->GetInterface();
         const SfxSlot *pSlot = pIFace->GetSlot(nSlot);
 
@@ -1646,7 +1654,8 @@ bool SfxDispatcher::FillState_(const SfxSlotServer& rSvr, SfxItemSet& rState,
 
         // Determine the object and call the Message of this object
         SfxShell *pSh = GetShell(rSvr.GetShellLevel());
-        DBG_ASSERT(pSh, "ObjectShell not found");
+        if (!pSh)
+            return false;
 
         SfxStateFunc pFunc;
 
diff --git a/sfx2/source/control/unoctitm.cxx b/sfx2/source/control/unoctitm.cxx
index 6f68292f46b4..45588bf1ccb9 100644
--- a/sfx2/source/control/unoctitm.cxx
+++ b/sfx2/source/control/unoctitm.cxx
@@ -860,9 +860,7 @@ void SfxDispatchController_Impl::StateChanged( sal_uInt16 nSID, SfxItemState eSt
         // TODO/LATER: what about the FormShell? Does it use any metric data?! Perhaps it should use the Pool of the document!
         if ( pSlotServ && pDispatcher )
         {
-            SfxShell* pShell = pDispatcher->GetShell( pSlotServ->GetShellLevel() );
-            DBG_ASSERT( pShell, "Can't get core metric without shell!" );
-            if ( pShell )
+            if (SfxShell* pShell = pDispatcher->GetShell( pSlotServ->GetShellLevel() ))
                 eMapUnit = GetCoreMetric( pShell->GetPool(), nSID );
         }
 
diff --git a/sfx2/source/view/viewfrm.cxx b/sfx2/source/view/viewfrm.cxx
index 68ea4a3f8933..f20d4932494a 100644
--- a/sfx2/source/view/viewfrm.cxx
+++ b/sfx2/source/view/viewfrm.cxx
@@ -954,6 +954,9 @@ void SfxViewFrame::ExecHistory_Impl( SfxRequest &rReq )
 {
     // Is there an Undo-Manager on the top Shell?
     SfxShell *pSh = GetDispatcher()->GetShell(0);
+    if (!pSh)
+        return;
+
     SfxUndoManager* pShUndoMgr = pSh->GetUndoManager();
     bool bOK = false;
     if ( pShUndoMgr )