Bug#17261 Passing a variable from a stored procedure to UDF crashes mysqld

- Update of test toolsand Makefiles to make it possible to test always test udf's as part of the mysql test suite mysql-test/mysql-test-run.pl: Add the path where mysqld will udf_example.so used by the udf test mysql-test/r/udf.result: Update test results mysql-test/t/udf.test: Update tests The "--error 0" directives should actually be changed to the correct error number returned but that error number is lost. W e do however get the right error message and that is checked in the .result file. sql/Makefile.am: Build shared library udf_example.so sql/share/errmsg.txt: Update the max length of %s string from 64 to 128 sql/sql_udf.cc: Add DBUG_PRINT just before dl_open sql/udf_example.cc: Use isalpha instade of my_isalpha
2025-12-24 11:21:21 +03:00 · 2006-03-10 10:41:04 +01:00
parent 79258e4480
commit e52ff5557c
7 changed files with 83 additions and 62 deletions
--- a/mysql-test/mysql-test-run.pl
+++ b/mysql-test/mysql-test-run.pl
@@ -1104,6 +1104,14 @@ sub environment_setup () {
        ($ENV{'DYLD_LIBRARY_PATH'} ? ":$ENV{'DYLD_LIBRARY_PATH'}" : "");
  }

+  # --------------------------------------------------------------------------
+  # Add the path where mysqld will find udf_example.so
+  # --------------------------------------------------------------------------
+  $ENV{'LD_LIBRARY_PATH'}=
+    "$glob_basedir/sql/.libs" .
+      ($ENV{'LD_LIBRARY_PATH'} ? ":$ENV{'LD_LIBRARY_PATH'}" : "");
+
+
  # --------------------------------------------------------------------------
  # Also command lines in .opt files may contain env vars
  # --------------------------------------------------------------------------
--- a/mysql-test/r/udf.result
+++ b/mysql-test/r/udf.result
@@ -10,7 +10,7 @@ RETURNS STRING SONAME 'udf_example.so';
 CREATE AGGREGATE FUNCTION avgcost
 RETURNS REAL SONAME 'udf_example.so';
 select myfunc_double();
-ERROR HY000: myfunc_double must have at least on argument
+ERROR HY000: myfunc_double must have at least one argument
 select myfunc_double(1);
 myfunc_double(1)
 49.00
@@ -59,18 +59,18 @@ select metaphon('hello');
 metaphon('hello')
 HL
 CREATE PROCEDURE `XXX1`(in testval varchar(10))
-begin 
-select metaphon(testval); 
+begin
+select metaphon(testval);
 end//
 call XXX1('hello');
 metaphon(testval)
 HL
 drop procedure xxx1;
 CREATE PROCEDURE `XXX2`()
-begin 
+begin
 declare testval varchar(10);
 set testval = 'hello';
-select metaphon(testval); 
+select metaphon(testval);
 end//
 call XXX2();
 metaphon(testval)
--- a/mysql-test/t/udf.test
+++ b/mysql-test/t/udf.test
@@ -1,7 +1,7 @@
 --source include/have_udf.inc
 #
-# To run this tests you need to compile "sql/udf_example.cc" into
-# udf_example.so and setup LD_LIBRARY_PATH to point out where 
+# To run this tests the "sql/udf_example.cc" need to be compiled into
+# udf_example.so and LD_LIBRARY_PATH should be setup to point out where
 # the library are.
 #

@@ -10,7 +10,7 @@
 drop table if exists t1;
 --enable_warnings

-# 
+#
 # Create the example functions from udf_example
 #

@@ -19,7 +19,7 @@ CREATE FUNCTION myfunc_double RETURNS REAL SONAME 'udf_example.so';

 # myfunc_int does not have a myfunc_int_init function and can 
 # not be loaded unless server is started with --allow-suspicious-udfs
--error 1127
+--error ER_CANT_FIND_DL_ENTRY
 CREATE FUNCTION myfunc_int RETURNS INTEGER SONAME 'udf_example.so';
 CREATE FUNCTION sequence RETURNS INTEGER SONAME "udf_example.so";
 CREATE FUNCTION lookup RETURNS STRING SONAME 'udf_example.so';
@@ -28,19 +28,27 @@ CREATE FUNCTION reverse_lookup
 CREATE AGGREGATE FUNCTION avgcost
        RETURNS REAL SONAME 'udf_example.so';

+--error 0
 select myfunc_double();
 select myfunc_double(1);
 select myfunc_double(78654);
+--error 1305
 select myfunc_int();
+--error 0
 select lookup();
 select lookup("127.0.0.1");
+--error 0
 select lookup(127,0,0,1);
 select lookup("localhost");
+--error 0
 select reverse_lookup();
 select reverse_lookup("127.0.0.1");
+--error 0
 select reverse_lookup(127,0,0,1);
 select reverse_lookup("localhost");
+--error 0
 select avgcost();
+--error 0
 select avgcost(100,23.76);
 create table t1(sum int, price float(24));
 insert into t1 values(100, 50.00), (100, 100.00);
@@ -54,12 +62,12 @@ drop table t1;
 # BUG#17261 Passing a variable from a stored procedure to UDF crashes mysqld
 #------------------------------------------------------------------------

-select metaphon('hello'); 
+select metaphon('hello');

 delimiter //;
 CREATE PROCEDURE `XXX1`(in testval varchar(10))
-begin 
-select metaphon(testval); 
+begin
+select metaphon(testval);
 end//
 delimiter ;//

@@ -68,10 +76,10 @@ drop procedure xxx1;

 delimiter //;
 CREATE PROCEDURE `XXX2`()
-begin 
+begin
 declare testval varchar(10);
 set testval = 'hello';
-select metaphon(testval); 
+select metaphon(testval);
 end//
 delimiter ;//

@@ -79,13 +87,13 @@ call XXX2();
 drop procedure xxx2;


-# 
+#
 # Drop the example functions from udf_example
 #

 DROP FUNCTION metaphon;
 DROP FUNCTION myfunc_double;
--error 1305
+--error ER_SP_DOES_NOT_EXIST
 DROP FUNCTION myfunc_int;
 DROP FUNCTION sequence;
 DROP FUNCTION lookup;
--- a/sql/Makefile.am
+++ b/sql/Makefile.am
@@ -153,10 +153,12 @@ sql_yacc.o:	sql_yacc.cc sql_yacc.h $(HEADERS)
 lex_hash.h:	gen_lex_hash$(EXEEXT)
 		./gen_lex_hash$(EXEEXT) > $@

-# For testing of udf_example.so;  Works on platforms with gcc
-# (This is not part of our build process but only provided as an example)
-udf_example.so:	udf_example.cc
-		$(CXXCOMPILE) -shared -o $@ $<
+# For testing of udf_example.so
+noinst_LTLIBRARIES= udf_example.la
+udf_example_la_SOURCES= udf_example.cc
+udf_example_la_CXXFLAGS= -DSTANDARD
+udf_example_la_LDFLAGS= -module -rpath $(pkglibdir)
+

 # Don't update the files from bitkeeper
 %::SCCS/s.%
--- a/sql/share/errmsg.txt
+++ b/sql/share/errmsg.txt
@@ -2978,23 +2978,23 @@ ER_UDF_EXISTS
 	swe "Funktionen '%-.64s' finns redan"
 	ukr "<22><><EFBFBD><EFBFBD>æ<EFBFBD> '%-.64s' <20><><EFBFBD> <20><><EFBFBD>դ"
 ER_CANT_OPEN_LIBRARY  
-	cze "Nemohu otev-B<><42>t sd<73>lenou knihovnu '%-.64s' (errno: %d %s)"
-	dan "Kan ikke <20>bne delt bibliotek '%-.64s' (errno: %d %s)"
-	nla "Kan shared library '%-.64s' niet openen (Errcode: %d %s)"
-	eng "Can't open shared library '%-.64s' (errno: %d %-.64s)"
-	jps "shared library '%-.64s' <20><><EFBFBD>J<EFBFBD><4A><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ł<EFBFBD><C582>܂<EFBFBD><DC82><EFBFBD> (errno: %d %s)",
-	est "Ei suuda avada jagatud teeki '%-.64s' (veakood: %d %-.64s)"
-	fre "Impossible d'ouvrir la biblioth<74>que partag<61>e '%-.64s' (errno: %d %s)"
-	ger "Kann Shared Library '%-.64s' nicht <20>ffnen (Fehler: %d %-.64s)"
-	greek "<22><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> shared library '%-.64s' (<28><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>: %d %s)"
-	hun "A(z) '%-.64s' megosztott konyvtar nem hasznalhato (hibakod: %d %s)"
-	ita "Impossibile aprire la libreria condivisa '%-.64s' (errno: %d %s)"
-	jpn "shared library '%-.64s' <20>򳫤<EFBFBD><F2B3ABA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǥ<EFBFBD><C7A4>ޤ<EFBFBD><DEA4><EFBFBD> (errno: %d %s)"
-	kor "'%-.64s' <20><><EFBFBD><EFBFBD> <20><><EFBFBD>̹<EFBFBD><CCB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>ϴ<EFBFBD>.(<28><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȣ: %d %s)"
-	nor "Can't open shared library '%-.64s' (errno: %d %s)"
-	norwegian-ny "Can't open shared library '%-.64s' (errno: %d %s)"
-	pol "Can't open shared library '%-.64s' (errno: %d %s)"
-	por "N<>o pode abrir biblioteca compartilhada '%-.64s' (erro no. '%d' - '%-.64s')"
+	cze "Nemohu otev-B<><42>t sd<73>lenou knihovnu '%-.64s' (errno: %d %-.128s)"
+	dan "Kan ikke <20>bne delt bibliotek '%-.64s' (errno: %d %-.128s)"
+	nla "Kan shared library '%-.64s' niet openen (Errcode: %d %-.128s)"
+	eng "Can't open shared library '%-.64s' (errno: %d %-.128s)"
+	jps "shared library '%-.64s' <20><><EFBFBD>J<EFBFBD><4A><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ł<EFBFBD><C582>܂<EFBFBD><DC82><EFBFBD> (errno: %d %-.128s)",
+	est "Ei suuda avada jagatud teeki '%-.64s' (veakood: %d %-.128s)"
+	fre "Impossible d'ouvrir la biblioth<74>que partag<61>e '%-.64s' (errno: %d %-.128s)"
+	ger "Kann Shared Library '%-.64s' nicht <20>ffnen (Fehler: %d %-.128s)"
+	greek "<22><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> shared library '%-.64s' (<28><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>: %d %-.128s)"
+	hun "A(z) '%-.64s' megosztott konyvtar nem hasznalhato (hibakod: %d %-.128s)"
+	ita "Impossibile aprire la libreria condivisa '%-.64s' (errno: %d %-.128s)"
+	jpn "shared library '%-.64s' <20>򳫤<EFBFBD><F2B3ABA4><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǥ<EFBFBD><C7A4>ޤ<EFBFBD><DEA4><EFBFBD> (errno: %d %-.128s)"
+	kor "'%-.64s' <20><><EFBFBD><EFBFBD> <20><><EFBFBD>̹<EFBFBD><CCB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD>ϴ<EFBFBD>.(<28><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ȣ: %d %-.128s)"
+	nor "Can't open shared library '%-.64s' (errno: %d %-.128s)"
+	norwegian-ny "Can't open shared library '%-.64s' (errno: %d %-.128s)"
+	pol "Can't open shared library '%-.64s' (errno: %d %-.128s)"
+	por "N<>o pode abrir biblioteca compartilhada '%-.64s' (erro no. '%d' - '%-.128s')"
 	rum "Nu pot deschide libraria shared '%-.64s' (Eroare: %d %-.64s)"
 	rus "<22><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> '%-.64s' (<28><><EFBFBD><EFBFBD><EFBFBD><EFBFBD>: %d %-.64s)"
 	serbian "Ne mogu da otvorim share-ovanu biblioteku '%-.64s' (errno: %d %-.64s)"
@@ -3003,27 +3003,27 @@ ER_CANT_OPEN_LIBRARY
 	swe "Kan inte <20>ppna det dynamiska biblioteket '%-.64s' (Felkod: %d %s)"
 	ukr "<22><> <20><><EFBFBD><EFBFBD> צ<><D7A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD>Ħ<EFBFBD><C4A6><EFBFBD><EFBFBD><EFBFBD><EFBFBD> ¦<>̦<EFBFBD><CCA6><EFBFBD><EFBFBD><EFBFBD> '%-.64s' (<28><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>: %d %-.64s)"
 ER_CANT_FIND_DL_ENTRY  
-	cze "Nemohu naj-B<>t funkci '%-.64s' v knihovn<76>"
-	dan "Kan ikke finde funktionen '%-.64s' i bibliotek"
-	nla "Kan functie '%-.64s' niet in library vinden"
-	eng "Can't find function '%-.64s' in library"
-	jps "function '%-.64s' <20><><EFBFBD><EFBFBD><EFBFBD>C<EFBFBD>u<EFBFBD><75><EFBFBD><EFBFBD><EFBFBD>[<5B><><EFBFBD>Ɍ<EFBFBD><C98C>t<EFBFBD><74><EFBFBD>鎖<EFBFBD><E98E96><EFBFBD>ł<EFBFBD><C582>܂<EFBFBD><DC82><EFBFBD>",
-	est "Ei leia funktsiooni '%-.64s' antud teegis"
-	fre "Impossible de trouver la fonction '%-.64s' dans la biblioth<74>que"
-	ger "Kann Funktion '%-.64s' in der Library nicht finden"
-	greek "<22><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> '%-.64s' <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>"
-	hun "A(z) '%-.64s' fuggveny nem talalhato a konyvtarban"
-	ita "Impossibile trovare la funzione '%-.64s' nella libreria"
-	jpn "function '%-.64s' <20><><EFBFBD>饤<EFBFBD>֥<EFBFBD><D6A5>꡼<EFBFBD><EAA1BC><EFBFBD>˸<EFBFBD><CBB8>դ<EFBFBD><D5A4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǥ<EFBFBD><C7A4>ޤ<EFBFBD><DEA4><EFBFBD>"
-	kor "<22><><EFBFBD>̹<EFBFBD><CCB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> '%-.64s' <20>Լ<EFBFBD><D4BC><EFBFBD> ã<><C3A3> <20><> <20><><EFBFBD><EFBFBD><EFBFBD>ϴ<EFBFBD>."
-	por "N<>o pode encontrar a fun<75><6E>o '%-.64s' na biblioteca"
-	rum "Nu pot gasi functia '%-.64s' in libraria"
-	rus "<22><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> '%-.64s' <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>"
-	serbian "Ne mogu da pronadjem funkciju '%-.64s' u biblioteci"
-	slo "Nem<65><6D>em n<>js<6A> funkciu '%-.64s' v kni<6E>nici"
-	spa "No puedo encontrar funci<63>n '%-.64s' en libraria"
-	swe "Hittar inte funktionen '%-.64s' in det dynamiska biblioteket"
-	ukr "<22><> <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>æ<EFBFBD> '%-.64s' <20> ¦<>̦<EFBFBD><CCA6><EFBFBD>æ"
+	cze "Nemohu naj-B<>t funkci '%-.128s' v knihovn<76>"
+	dan "Kan ikke finde funktionen '%-.128s' i bibliotek"
+	nla "Kan functie '%-.128s' niet in library vinden"
+	eng "Can't find function '%-.128s' in library"
+	jps "function '%-.128s' <20><><EFBFBD><EFBFBD><EFBFBD>C<EFBFBD>u<EFBFBD><75><EFBFBD><EFBFBD><EFBFBD>[<5B><><EFBFBD>Ɍ<EFBFBD><C98C>t<EFBFBD><74><EFBFBD>鎖<EFBFBD><E98E96><EFBFBD>ł<EFBFBD><C582>܂<EFBFBD><DC82><EFBFBD>",
+	est "Ei leia funktsiooni '%-.128s' antud teegis"
+	fre "Impossible de trouver la fonction '%-.128s' dans la biblioth<74>que"
+	ger "Kann Funktion '%-.128s' in der Library nicht finden"
+	greek "<22><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> '%-.128s' <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>"
+	hun "A(z) '%-.128s' fuggveny nem talalhato a konyvtarban"
+	ita "Impossibile trovare la funzione '%-.128s' nella libreria"
+	jpn "function '%-.128s' <20><><EFBFBD>饤<EFBFBD>֥<EFBFBD><D6A5>꡼<EFBFBD><EAA1BC><EFBFBD>˸<EFBFBD><CBB8>դ<EFBFBD><D5A4><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ǥ<EFBFBD><C7A4>ޤ<EFBFBD><DEA4><EFBFBD>"
+	kor "<22><><EFBFBD>̹<EFBFBD><CCB9><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> '%-.128s' <20>Լ<EFBFBD><D4BC><EFBFBD> ã<><C3A3> <20><> <20><><EFBFBD><EFBFBD><EFBFBD>ϴ<EFBFBD>."
+	por "N<>o pode encontrar a fun<75><6E>o '%-.128s' na biblioteca"
+	rum "Nu pot gasi functia '%-.128s' in libraria"
+	rus "<22><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> '%-.128s' <20> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>"
+	serbian "Ne mogu da pronadjem funkciju '%-.128s' u biblioteci"
+	slo "Nem<65><6D>em n<>js<6A> funkciu '%-.128s' v kni<6E>nici"
+	spa "No puedo encontrar funci<63>n '%-.128s' en libraria"
+	swe "Hittar inte funktionen '%-.128s' in det dynamiska biblioteket"
+	ukr "<22><> <20><><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD> <20><><EFBFBD><EFBFBD>æ<EFBFBD> '%-.128s' <20> ¦<>̦<EFBFBD><CCA6><EFBFBD>æ"
 ER_FUNCTION_NOT_DEFINED  
 	cze "Funkce '%-.64s' nen-B<> definov<6F>na"
 	dan "Funktionen '%-.64s' er ikke defineret"
--- a/sql/sql_udf.cc
+++ b/sql/sql_udf.cc
@@ -432,6 +432,7 @@ int mysql_create_function(THD *thd,udf_func *udf)
  }
  if (!(dl = find_udf_dl(udf->dl)))
  {
+    DBUG_PRINT("info", ("Calling dlopen, udf->dl: %s", udf->dl));
    if (!(dl = dlopen(udf->dl, RTLD_NOW)))
    {
      DBUG_PRINT("error",("dlopen of %s failed, error: %d (%s)",
--- a/sql/udf_example.cc
+++ b/sql/udf_example.cc
@@ -113,6 +113,8 @@
 */

 #ifdef STANDARD
+/* STANDARD is defined, don't use any mysql functions */
+#include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #ifdef __WIN__
@@ -125,10 +127,10 @@ typedef long long longlong;
 #else
 #include <my_global.h>
 #include <my_sys.h>
+#include <m_string.h>		// To get strmov()
 #endif
 #include <mysql.h>
-#include <m_ctype.h>
-#include <m_string.h>		// To get strmov()
+#include <ctype.h>

 static pthread_mutex_t LOCK_hostname;

@@ -289,8 +291,8 @@ char *metaphon(UDF_INIT *initid, UDF_ARGS *args, char *result,

  for (n = ntrans + 1, n_end = ntrans + sizeof(ntrans)-2;
 	word != w_end && n < n_end; word++ )
-    if ( my_isalpha ( &my_charset_latin1, *word ))
-      *n++ = my_toupper ( &my_charset_latin1, *word );
+    if ( isalpha ( *word ))
+      *n++ = toupper ( *word );

  if ( n == ntrans + 1 )	/* return empty string if 0 bytes */
  {