autofill increment needs a bit more tolerance, fdo#37424

sal/inc/rtl/math.hxx

@@ -263,6 +263,19 @@ inline bool approxEqual(double a, double b)
         < ((a < 0.0 ? -a : a) * (1.0 / (16777216.0 * 16777216.0)));
 }
 
+/** Test equality of two values with an accuracy defined by nPrec
+
+    @attention
+    approxEqual( value!=0.0, 0.0 ) _never_ yields true.
+ */
+inline bool approxEqual(double a, double b, sal_Int16 nPrec)
+{
+    if ( a == b )
+        return true;
+    double x = a - b;
+    return (x < 0.0 ? -x : x)
+        < ((a < 0.0 ? -a : a) * (1.0 / (pow(2, nPrec))));
+}
 /** Add two values.
 
     If signs differ and the absolute values are equal according to approxEqual()

sc/source/core/data/table4.cxx

@@ -324,7 +324,7 @@ void ScTable::FillAnalyse( SCCOL nCol1, SCROW nRow1, SCCOL nCol2, SCROW nRow2,
                     {
                         nVal2 = ((ScValueCell*)pCell)->GetValue();
                         double nDiff = nVal2 - nVal1;
-                        if ( !::rtl::math::approxEqual( nDiff, rInc ) )
+                        if ( !::rtl::math::approxEqual( nDiff, rInc, 13 ) )
                             bVal = false;
                         nVal1 = nVal2;
                     }
@@ -395,7 +395,7 @@ void ScTable::FillAnalyse( SCCOL nCol1, SCROW nRow1, SCCOL nCol2, SCROW nRow2,
                             if ( nFlag1 == nFlag2 )
                             {
                                 double nDiff = (double)nVal2 - (double)nVal1;
-                                if ( !::rtl::math::approxEqual( nDiff, rInc ) )
+                                if ( !::rtl::math::approxEqual( nDiff, rInc, 13 ) )
                                     bVal = false;
                                 nVal1 = nVal2;
                             }