Partially revert ada2630699

Of course, MacOSX only has posix_memalign, and only in recent versions.
(Older versions could use valloc instead. That precludes ever changing
the LMDB pagesize to be different from the OS pagesize.) Not all that
crucial since it only affects mdb_env_copyfd1.

libraries/liblmdb/mdb.c

@@ -79,17 +79,23 @@ extern int cacheflush(char *addr, int nbytes, int cache);
 #define CACHEFLUSH(addr, bytes, cache)
 #endif
 
+
 #include <errno.h>
 #include <limits.h>
 #include <stddef.h>
 #include <inttypes.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <malloc.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
 
+#if defined(__sun)
+/* Most platforms have posix_memalign, older may only have memalign */
+#define HAVE_MEMALIGN	1
+#include <malloc.h>
+#endif
+
 #if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER))
 #include <netinet/in.h>
 #include <resolv.h>	/* defines BYTE_ORDER on HPUX and Solaris */
@@ -8480,9 +8486,15 @@ mdb_env_copyfd1(MDB_env *env, HANDLE fd)
 #else
 	pthread_mutex_init(&my.mc_mutex, NULL);
 	pthread_cond_init(&my.mc_cond, NULL);
+#ifdef HAVE_MEMALIGN
 	my.mc_wbuf[0] = memalign(env->me_os_psize, MDB_WBUF*2);
 	if (my.mc_wbuf[0] == NULL)
 		return errno;
+#else
+	rc = posix_memalign((void **)&my.mc_wbuf[0], env->me_os_psize, MDB_WBUF*2);
+	if (rc)
+		return rc;
+#endif
 #endif
 	memset(my.mc_wbuf[0], 0, MDB_WBUF*2);
 	my.mc_wbuf[1] = my.mc_wbuf[0] + MDB_WBUF;