https://sourceforge.net/p/mhash/patches/11/

Compiling mhash-0.9.9.9 on platforms (like AIX) without GNU libc compatible malloc leads to undefined symbol rpl_malloc
when linking the in-mhash executables drver, frag_test, rest_test, hmac_test, keygen_test.

Reason is that configure.in still contains AC_FUNC_MALLOC, detecting need
to "#define malloc rpl_malloc", while mhash does not provide a rpl_malloc implementation.

As the only use of malloc() in lib/stdfns.c does not rely on GNU libc
compatible malloc actually, there is no need to check for one.
--- a/configure.in
+++ b/configure.in
@@ -64,7 +64,6 @@ AC_CHECK_HEADERS(signal.h stdint.h stdio.h stdlib.h string.h strings.h)
 
 dnl Checks for functions
 
-AC_FUNC_MALLOC
 AC_FUNC_MEMCMP
 
 AC_CHECK_FUNCS(bcopy bzero)