crashtesting: frequent nulldef at end of SwTextFrame::ValidateFrame

maybe since...

commit 1caea03f
Date:   Mon May 6 15:40:41 2019 +0200

    tdf#122892 tdf#124366 sw: fix loop in SwTextFrame::CalcFollow()

though it happens in the idle callback and isn't easily reproducible

Change-Id: Iadcd735661ab42908061e80d72c8b32a0c075726
Reviewed-on: https://gerrit.libreoffice.org/72198
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sw/source/core/text/frmform.cxx

@@ -108,10 +108,12 @@ void SwTextFrame::ValidateFrame()
 
     // We at least have to save the MustFit flag!
     OSL_ENSURE( HasPara(), "ResetPreps(), missing ParaPortion." );
-    SwParaPortion *pPara = GetPara();
-    const bool bMustFit = pPara->IsPrepMustFit();
-    ResetPreps();
-    pPara->SetPrepMustFit( bMustFit );
+    if (SwParaPortion *pPara = GetPara())
+    {
+        const bool bMustFit = pPara->IsPrepMustFit();
+        ResetPreps();
+        pPara->SetPrepMustFit( bMustFit );
+    }
 }
 
 // After a RemoveFootnote the BodyFrame and all Frames contained within it, need to be

sw/source/core/text/txtfrm.cxx

@@ -1337,8 +1337,7 @@ void SwTextFrame::ResetPreps()
 {
     if ( GetCacheIdx() != USHRT_MAX )
     {
-        SwParaPortion *pPara;
-        if( nullptr != (pPara = GetPara()) )
+        if (SwParaPortion *pPara = GetPara())
             pPara->ResetPreps();
     }
 }