alloccopy: explicit no-op on zero size.

Allows src/dst to be null for zero size, which memcpy doesn't

1 files changed, 1 insertions, 0 deletions

diff --git a/common.h b/common.h
index 0e10a8e..ef4d4d7 100644
--- a/common.h
+++ b/common.h
@@ -244,6 +244,7 @@ void *allocz(struct arena **, uint siz, uint align);
 static inline void *
 alloccopy(struct arena **arena, const void *src, uint siz, uint align)
 {
+   if (!siz) return NULL;
    return memcpy(alloc(arena, siz, align), src, siz);
 }
 void freearena(struct arena **);