tdf#115044: do not load external documents if it is not allowed

Referenced external document data can be loaded after user
permission from dialog or corresponding settings.

Change-Id: If3aec37c8bbdee4aebeb99c7807e87c26df8e592
Reviewed-on: https://gerrit.libreoffice.org/48398Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Eike Rathke <erack@redhat.com>

sc/source/ui/docshell/externalrefmgr.cxx

@@ -2365,6 +2365,15 @@ ScDocument* ScExternalRefManager::getInMemorySrcDocument(sal_uInt16 nFileId)
     if (!pFileName)
         return nullptr;
 
+    // Do not load document until it was allowed
+    SfxObjectShell* pDocShell = mpDoc->GetDocumentShell();
+    if ( pDocShell )
+    {
+        const comphelper::EmbeddedObjectContainer& rContainer = pDocShell->GetEmbeddedObjectContainer();
+        if ( !rContainer.getUserAllowsLinkUpdate() )
+            return nullptr;
+    }
+
     ScDocument* pSrcDoc = nullptr;
     ScDocShell* pShell = static_cast<ScDocShell*>(SfxObjectShell::GetFirst(checkSfxObjectShell<ScDocShell>, false));
     while (pShell)