Do not call BCOPY and BZERO if size is zero

* dbg_mlc.c (GC_debug_strndup): Do not call BCOPY() if elements count
is zero.
* dbg_mlc.c (GC_debug_realloc): Likewise.
* finalize.c [!GC_TOGGLE_REFS_NOT_NEEDED] (ensure_toggleref_capacity):
Likewise.
* malloc.c [REDIRECT_MALLOC && !strndup] (strndup): Likewise.
* mallocx.c (GC_strndup): Likewise.
* misc.c [!GC_GET_HEAP_USAGE_NOT_NEEDED] (GC_get_prof_stats): Likewise.
* os_dep.c [SAVE_CALL_CHAIN && GC_HAVE_BUILTIN_BACKTRACE]
(GC_save_callers): Likewise.
* reclaim.c (GC_print_all_errors): Likewise.
* malloc.c (GC_free): Do not call BZERO() if elements count is zero.
* malloc.c [THREADS] (GC_free_inner): Likewise.
* reclaim.c (GC_print_all_errors): Likewise.
* misc.c [!GC_GET_HEAP_USAGE_NOT_NEEDED && THREADS]
(GC_get_prof_stats_unsafe): Do not call fill_prof_stats() and BCOPY()
if stats_sz is zero.

1 files changed, 2 insertions, 1 deletions

diff --git a/mallocx.c b/mallocx.c
index f7a680a1..7b6f62cf 100644
--- a/mallocx.c
+++ b/mallocx.c
@@ -542,7 +542,8 @@ GC_API GC_ATTR_MALLOC char * GC_CALL GC_strndup(const char *str, size_t size)
 #   endif
     return NULL;
   }
-  BCOPY(str, copy, len);
+  if (EXPECT(len > 0, TRUE))
+    BCOPY(str, copy, len);
   copy[len] = '\0';
   return copy;
 }