moments: Fix null pointer dereference in calc_moments().

Found by Clang (http://clang-analyzer.llvm.org).

diff --git a/src/math/moments.c b/src/math/moments.c
index d129f6ab038b3eee06104e716b15fbcf432c61c5..545c9644399a9501765455cfc99505be30e8d460 100644 (file)
--- a/src/math/moments.c
+++ b/src/math/moments.c
@@ -1,5 +1,5 @@
 /* PSPP - a program for statistical analysis.
-   Copyright (C) 1997-9, 2000 Free Software Foundation, Inc.
+   Copyright (C) 1997-9, 2000, 2010 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -49,7 +49,7 @@ calc_moments (enum moment max_moment,
 
       /* From _SPSS Statistical Algorithms, 2nd ed.,
          0-918469-89-9, section "DESCRIPTIVES". */
-      if (fabs (*variance) >= 1e-20)
+      if (fabs (s2) >= 1e-20)
         {
           if (max_moment >= MOMENT_SKEWNESS && skewness != NULL && w > 2.)
             {