Fix matrix pointer dereference bug in update.c

The PGI compiler found a bug where an if-statement
checked against a dereferenced pointer rather than
the pointer itself being non-NULL.

Change-Id: If08977b818f28e1c78c35222d0f4efe6ae6aad65

diff --git a/src/gromacs/mdlib/update.c b/src/gromacs/mdlib/update.c
index e5a095baace0f339528a1f6cf3ccc8e77373cc0b..787135f7158cd12b23bac96a7446d7de8d8e44a7 100644 (file)
--- a/src/gromacs/mdlib/update.c
+++ b/src/gromacs/mdlib/update.c
@@ -1318,7 +1318,7 @@ static void deform(gmx_update_t upd,
         x[i][YY] = mu[YY][YY]*x[i][YY]+mu[ZZ][YY]*x[i][ZZ];
         x[i][ZZ] = mu[ZZ][ZZ]*x[i][ZZ];
     }
-    if (*scale_tot)
+    if (scale_tot != NULL)
     {
         /* The transposes of the scaling matrices are stored,
          * so we need to do matrix multiplication in the inverse order.