Prevent panic when incorrect range is provided as PivotTableRange to (#874)

adjust.go

@@ -198,6 +198,10 @@ func (f *File) adjustAutoFilterHelper(dir adjustDirection, coordinates []int, nu
 // pair of coordinates.
 func (f *File) areaRefToCoordinates(ref string) ([]int, error) {
 	rng := strings.Split(strings.Replace(ref, "$", "", -1), ":")
+	if len(rng) < 2 {
+		return nil, ErrParameterInvalid
+	}
+
 	return areaRangeToCoordinates(rng[0], rng[1])
 }
 

pivotTable_test.go

@@ -228,6 +228,9 @@ func TestAddPivotTable(t *testing.T) {
 	// Test adjust range with invalid range
 	_, _, err := f.adjustRange("")
 	assert.EqualError(t, err, "parameter is required")
+	// Test adjust range with incorrect range
+	_, _, err = f.adjustRange("sheet1!")
+	assert.EqualError(t, err, "parameter is invalid")
 	// Test get pivot fields order with empty data range
 	_, err = f.getPivotFieldsOrder(&PivotTableOption{})
 	assert.EqualError(t, err, `parameter 'DataRange' parsing error: parameter is required`)