__malloc_initialized is already = 1, at the first initialize() call:

hostname@makoto 09:17:46/110920(..editors/mule)% 
  (cd work/mule/src; grep __malloc_initialized *alloc.c) 
gmalloc.c:extern int __malloc_initialized;
gmalloc.c:int __malloc_initialized = 0;
gmalloc.c:  __malloc_initialized = 1;
gmalloc.c:  fprintf(stderr, "%s: %s:%d %08x\n",
	__func__, __FILE__,__LINE__, __malloc_initialized);
gmalloc.c:  if (!__malloc_initialized){
gmalloc.c:  //  fprintf(stderr, "%s: %s:%d %08x\n",
	__func__, __FILE__,__LINE__, __malloc_initialized);
vmsgmalloc.c:extern int __malloc_initialized;
vmsgmalloc.c:int __malloc_initialized;
vmsgmalloc.c:  printf("__malloc_initialized = %d\n", __malloc_initialized);
vmsgmalloc.c:  __malloc_initialized = 1;
vmsgmalloc.c:  if (!__malloc_initialized)
vmsgmalloc.c:  int __malloc_initialized;
vmsgmalloc.c:  __malloc_initialized = ____vms_malloc_data[i].__malloc_initialized;
vmsgmalloc.c:  ____vms_malloc_data[i].__malloc_initialized = __malloc_initialized;
vmsgmalloc.c:  if (!__malloc_initialized && !mcheck_used)
hostname@makoto 09:17:50/110920(..editors/mule)% 

./emacs -batch 
  -l /export/pkgsrc/editors/mule/work/mule/src/../lisp/mule-diag.elc 
  -f dump-charset
init_strings: alloc.c:874 00001ffc
malloc: gmalloc.c:515 00000001
gmake[1]: *** [../etc/charset] Segmentation fault (core dumped)
gmake[1]: Leaving directory `/export/pkgsrc/editors/mule/work/mule/src'
gmake: *** [src] Error 2
*** Error code 2