branches/zip: trx0sys.h: Add a compile-time check that UNIV_PAGE_SIZE

is at least 4 kilobytes.

include/trx0sys.h

@@ -335,6 +335,9 @@ therefore 256; each slot is currently 8 bytes in size */
 #define TRX_SYS_MYSQL_LOG_NAME_LEN	512
 #define TRX_SYS_MYSQL_LOG_MAGIC_N	873422344
 
+#if UNIV_PAGE_SIZE < 4096
+# error "UNIV_PAGE_SIZE < 4096"
+#endif
 /* The offset of the MySQL replication info in the trx system header;
 this contains the same fields as TRX_SYS_MYSQL_LOG_INFO below */
 #define TRX_SYS_MYSQL_MASTER_LOG_INFO	(UNIV_PAGE_SIZE - 2000)