IOUtil: abort IOUtil_TruncateOutputFiles if called too early

currently when called before the grid extension for IOUtil has been registered
(which is when IOUtils learns if the is a checkpoint recovery run or not), the
routine returns -1. However the documentation in the thorn guide states that

Thorn IOUtil provides an aliased function for other I/O thorns to call:
  CCTK_INT FUNCTION IO_TruncateOutputFiles (CCTK_POINTER_TO_CONST IN cctkGH)
This function simply returns 1 or 0 if output files should or should not be
truncated.

Since there are thorns out there that take this to heart and test for
IO_TruncateOutputFiles() being true (ie non-zero) these thorns always overwrite
data during a recovery when calling IOUtils too early. This happened to Carpet
in ticket #908.

The attached patch makes IOUtil abort instead which seems better than silently
returning the wrong (since undocumented) answer. No actual user thorn should be
affected.


git-svn-id: http://svn.cactuscode.org/arrangements/CactusBase/IOUtil/trunk@289 b32723a9-ab3a-4a60-88e2-2e5d99d7c17a

1 files changed, 2 insertions, 2 deletions

diff --git a/src/Startup.c b/src/Startup.c
index 5a50fce..8a66e7d 100644
--- a/src/Startup.c
+++ b/src/Startup.c
@@ -162,7 +162,6 @@ void IOUtil_UpdateParFile (CCTK_ARGUMENTS)
 
    @returntype CCTK_INT
    @returndesc 1 or 0 for truncate or not
-               -1 in case of an error (wrong value for GH parameter)
    @endreturndesc
 @@*/
 CCTK_INT IOUtil_TruncateOutputFiles (const CCTK_POINTER_TO_CONST GH)
@@ -174,7 +173,8 @@ CCTK_INT IOUtil_TruncateOutputFiles (const CCTK_POINTER_TO_CONST GH)
   myGH = CCTK_GHExtension (GH, "IO");
   if (! myGH)
   {
-    return (-1);
+    CCTK_WARN (CCTK_WARN_ABORT,
+               "IOUtil_TruncateOutputFiles called before being fully initialized. Please make sure to only call me after the STARTUP bin has finished and the driver called CCTKi_InitGHExtensions.");
   }
 
   return (myGH->recovered ? truncate_files_after_recovering : truncate_files);