BUG#58205 - Valgrind failure in fn_format when called from

            archive_discover

Fixed buffer underrun in cleanup_dirname().

Also fixed that original (unencoded) database and table
names were used to discover archive tables.

mysql-test/r/archive.result:
  A test case for BUG#58205.
mysql-test/t/archive.test:
  A test case for BUG#58205.
mysys/mf_pack.c:
  Fixed buffer underrun in cleanup_dirname(), when
  it gets path like "a/../" (relative path, where
  first directory is to be cut off).
storage/archive/ha_archive.cc:
  Handler discover method gets database and table
  names as is. It must use build_table_filename()
  to get name similar to what it gets on create()
  and open().

mysql-test/r/archive.result

@@ -12801,3 +12801,9 @@ t1	CREATE TABLE `t1` (
   `a` int(11) DEFAULT NULL
 ) ENGINE=ARCHIVE DEFAULT CHARSET=latin1
 DROP TABLE t1;
+#
+# BUG#58205 - Valgrind failure in fn_format when called from
+#             archive_discover
+#
+CREATE TABLE `a/../`(a INT) ENGINE=ARCHIVE;
+DROP TABLE `a/../`;

mysql-test/t/archive.test

@@ -1722,3 +1722,11 @@ INSERT INTO t1 VALUES (2);
 SELECT * FROM t1 ORDER BY a;
 SHOW CREATE TABLE t1;
 DROP TABLE t1;
+
+--echo #
+--echo # BUG#58205 - Valgrind failure in fn_format when called from
+--echo #             archive_discover
+--echo #
+CREATE TABLE `a/../`(a INT) ENGINE=ARCHIVE;
+remove_file $MYSQLD_DATADIR/test/a@002f@002e@002e@002f.frm;
+DROP TABLE `a/../`;

mysys/mf_pack.c

@@ -192,7 +192,8 @@ size_t cleanup_dirname(register char *to, const char *from)
 	  end_parentdir=pos;
 	  while (pos >= start && *pos != FN_LIBCHAR)	/* remove prev dir */
 	    pos--;
-	  if (pos[1] == FN_HOMELIB || memcmp(pos,parent,length) == 0)
+          if (pos[1] == FN_HOMELIB ||
+              (pos > start && memcmp(pos, parent, length) == 0))
 	  {					/* Don't remove ~user/ */
 	    pos=strmov(end_parentdir+1,parent);
 	    *pos=FN_LIBCHAR;

storage/archive/ha_archive.cc

@@ -20,6 +20,7 @@
 #include "sql_priv.h"
 #include "probes_mysql.h"
 #include "sql_class.h"                          // SSV
+#include "sql_table.h"
 #include <myisam.h>
 
 #include "ha_archive.h"
@@ -256,7 +257,7 @@ int archive_discover(handlerton *hton, THD* thd, const char *db,
   char *frm_ptr;
   MY_STAT file_stat; 
 
-  fn_format(az_file, name, db, ARZ, MY_REPLACE_EXT | MY_UNPACK_FILENAME);
+  build_table_filename(az_file, sizeof(az_file) - 1, db, name, ARZ, 0);
 
   if (!(my_stat(az_file, &file_stat, MYF(0))))
     goto err;