Fix:
 * crashes on memory allocation failure found with failmalloc
 * memory leaks found with valgrind
 * compiler warnings in opt mode which would lead to invalid memory reads
 * problem using wrong name in decimal module reported by pychecker

Update the valgrind suppressions file with new leaks that are small/one-time
leaks we don't care about (ie, they are too hard to fix).

TBR=barry
TESTED=./python -E -tt ./Lib/test/regrtest.py -uall (both debug and opt modes)
  in opt mode:
  valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp \
    ./python -E -tt ./Lib/test/regrtest.py -uall,-bsddb,-compiler \
                        -x test_logging test_ssl test_multiprocessing
  valgrind -q --leak-check=yes --suppressions=Misc/valgrind-python.supp \
    ./python -E -tt ./Lib/test/regrtest.py test_multiprocessing
  for i in `seq 1 4000` ; do
    LD_PRELOAD=~/local/lib/libfailmalloc.so FAILMALLOC_INTERVAL=$i \
        ./python -c pass
  done

At least some of these fixes should probably be backported to 2.5.
diff --git a/Modules/_ctypes/stgdict.c b/Modules/_ctypes/stgdict.c
index cd38ecd..dabf9f1 100644
--- a/Modules/_ctypes/stgdict.c
+++ b/Modules/_ctypes/stgdict.c
@@ -416,6 +416,7 @@
 		ffi_ofs = 0;
 	}
 
+	assert(stgdict->format == NULL);
 	if (isStruct && !isPacked) {
 		stgdict->format = alloc_format_string(NULL, "T{");
 	} else {
@@ -539,7 +540,9 @@
 #undef realdict
 
 	if (isStruct && !isPacked) {
+		char *ptr = stgdict->format;
 		stgdict->format = alloc_format_string(stgdict->format, "}");
+		PyMem_Free(ptr);
 		if (stgdict->format == NULL)
 			return -1;
 	}
diff --git a/Modules/_fileio.c b/Modules/_fileio.c
index 58462dd..6b3a98d 100644
--- a/Modules/_fileio.c
+++ b/Modules/_fileio.c
@@ -278,6 +278,7 @@
 	ret = -1;
 
  done:
+	PyMem_Free(name);
 	return ret;
 }
 
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
index e297240..628780f 100644
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -784,7 +784,8 @@
 #if defined (HAVE_SETITIMER) || defined (HAVE_GETITIMER)
     ItimerError = PyErr_NewException("signal.ItimerError", 
          PyExc_IOError, NULL);
-    PyDict_SetItemString(d, "ItimerError", ItimerError);
+    if (ItimerError != NULL)
+    	PyDict_SetItemString(d, "ItimerError", ItimerError);
 #endif
 
         if (!PyErr_Occurred())