Fix a bug in CCTK_ParameterSet() .

The symptoms were that if you
(a) set the same parameter twice, *and*
(b) the second setting is an invalid value,
then current-CVS Cactus core-dumps inside the flesh trying to  free()
a garbage (uninitialized) pointer.

For example, the following par file suffices to trigger the core-dump,
using only flesh parameters (*no* thorns activated):

  # this par file causes a core dump in current-CVS Cactus
  Cactus::cctk_timer_output = "off"
  Cactus::cctk_timer_output = "foo"     # an illegal value for this parameter

Looking at the code,

   599        /* check if a parameter is set more than once in a parfile */
   600        if (cctk_parameter_set_mask == PARAMETER_RECOVERY_PRE &&
   601            param->props->n_set > 0)
   602        {
   603          if (retval == 0)
   604          {
   605            new_value = CCTK_ParameterValString (param->props->name,
   606                                                 param->props->thorn);
   607            retval = strcmp (old_value, new_value) ? -10 : -11;
   608          }
   609          free (new_value);
   610        }

Notice that the  free()  at line 609 may be executed even if  new_value
was *not* assigned a value at line 605.  Alas,  new_value  is a local
variable in this function, and is not explicitly initialized, so it
has a garbage value initially... and line 605 is its only assignment
in this function.

The fix is easy -- just move the free() up to right after line 607,
so it's executed if and only if  new_value  has been assigned.

patch was
  http://www.cactuscode.org/old/pipermail/patches/2006-April/000162.html
developers discussion was
  http://www.cactuscode.org/old/pipermail/developers/2006-April/001758.html
  http://www.cactuscode.org/old/pipermail/developers/2006-April/001759.html


git-svn-id: http://svn.cactuscode.org/flesh/trunk@4285 17b73243-c579-4c4c-a9d2-2d5706c11dac

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main/Parameters.c b/src/main/Parameters.c
index ef7069b3..cd8527ec 100644
--- a/src/main/Parameters.c
+++ b/src/main/Parameters.c
@@ -605,8 +605,8 @@ int CCTK_ParameterSet (const char *name, const char *thorn, const char *value)
           new_value = CCTK_ParameterValString (param->props->name,
                                                param->props->thorn);
           retval = strcmp (old_value, new_value) ? -10 : -11;
+          free (new_value);
         }
-        free (new_value);
       }
 
       /* register another set operation */