More nEndInvalid/COMPLETE_STRING fixes

...to fix -fsanitize=signed-integer-overflow

Change-Id: Ib8dad09f1ed088c51fb417efecf662e76b2e495a

sw/source/core/inc/wrong.hxx

@@ -211,7 +211,7 @@ public:
     inline bool InsideInvalid( sal_Int32 nChk ) const
         { return nChk >= nBeginInvalid && nChk <= nEndInvalid; }
     void SetInvalid( sal_Int32 nBegin, sal_Int32 nEnd );
-    inline void Validate(){ nBeginInvalid = COMPLETE_STRING; }
+    inline void Validate(){ nBeginInvalid = nEndInvalid = COMPLETE_STRING; }
     void Invalidate( sal_Int32 nBegin, sal_Int32 nEnd );
     bool InvalidateWrong();
     bool Fresh( sal_Int32 &rStart, sal_Int32 &rEnd, sal_Int32 nPos,

sw/source/core/text/wrong.cxx

@@ -313,7 +313,7 @@ void SwWrongList::Move( sal_Int32 nPos, sal_Int32 nDiff )
         {
             if( nBeginInvalid > nPos )
                 nBeginInvalid += nDiff;
-            if( nEndInvalid >= nPos )
+            if( nEndInvalid >= nPos && nEndInvalid != COMPLETE_STRING )
                 nEndInvalid += nDiff;
         }
         // If the pointer is in the middle of a wrong word,