More for prev commit

Use the latest meta page

libraries/liblmdb/mdb.c

@@ -2416,11 +2416,13 @@ mdb_env_read_header(MDB_env *env, MDB_meta *meta)
 	MDB_pagebuf	pbuf;
 	MDB_page	*p;
 	MDB_meta	*m;
-	int		 rc, err;
+	int		 i, rc, err;
 
 	/* We don't know the page size yet, so use a minimum value.
+	 * Read both meta pages so we can use the latest one.
 	 */
 
+	for (i=0; i<2; i++) {
 #ifdef _WIN32
 		if (!ReadFile(env->me_fd, &pbuf, MDB_PAGESIZE, (DWORD *)&rc, NULL) || rc == 0)
 #else
@@ -2456,7 +2458,19 @@ mdb_env_read_header(MDB_env *env, MDB_meta *meta)
 			return MDB_VERSION_MISMATCH;
 		}
 
+		if (i) {
+			if (m->mm_txnid > meta->mm_txnid)
 				memcpy(meta, m, sizeof(*m));
+		} else {
+			memcpy(meta, m, sizeof(*m));
+#ifdef _WIN32
+			if (SetFilePointer(env->me_fd, meta->mm_psize, NULL, FILE_BEGIN) != meta->mm_psize)
+#else
+			if (lseek(env->me_fd, meta->mm_psize, SEEK_SET) != meta->mm_psize)
+#endif
+				return ErrCode();
+		}
+	}
 	return 0;
 }