tdf#100843 LCM_EXCEL2003 fix incorrect handling of non-integer values.

Non-integer values should be truncated as Excel does.
Also, make the function return an error with negative values.

Change-Id: I6a8ce1fb82d20294d9398ca2af308f88b51d5e82
Reviewed-on: https://gerrit.libreoffice.org/27096Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>

scaddins/source/analysis/analysis.cxx

@@ -738,18 +738,22 @@ double SAL_CALL AnalysisAddIn::getLcm( const uno::Reference< beans::XPropertySet
     if( aValList.Count() == 0 )
         return 0.0;
 
-    double          f = aValList.Get(0);
+    double f = rtl::math::approxFloor( aValList.Get(0) );
+    if( f < 0.0 )
+        throw lang::IllegalArgumentException();
 
     if( f == 0.0 )
         return f;
 
     for( sal_uInt32 i = 1; i < aValList.Count(); ++i )
     {
-        double      fTmp = aValList.Get(i);
+        double fTmp = rtl::math::approxFloor( aValList.Get(i) );
+        if( fTmp < 0.0 )
+            throw lang::IllegalArgumentException();
+
+        f = fTmp * f / GetGcd( fTmp, f );
         if( f == 0.0 )
             return f;
-        else
-            f = fTmp * f / GetGcd( fTmp, f );
     }
 
     RETURN_FINITE( f );