Bug#15328 Segmentation fault occured if my.cnf is invalid for escape sequence

- Check that length of value is longer than 1 before decrementing length by 2.
 - Backport from 5.0, make it possible to use my_print_defaults in tests

mysql-test/mysql-test-run.pl

@@ -179,6 +179,7 @@ our $exe_mysqlshow;              # Called from test case
 our $exe_mysql_fix_system_tables;
 our $exe_mysqltest;
 our $exe_slave_mysqld;
+our $exe_my_print_defaults;
 
 our $opt_bench= 0;
 our $opt_small_bench= 0;
@@ -893,6 +894,8 @@ sub executable_setup () {
                                            "$path_client_bindir/mysqld-max");
       $path_language=      mtr_path_exists("$glob_basedir/share/english/");
       $path_charsetsdir=   mtr_path_exists("$glob_basedir/share/charsets");
+      $exe_my_print_defaults=
+	mtr_exe_exists("$path_client_bindir/my_print_defaults");
     }
     else
     {
@@ -900,6 +903,8 @@ sub executable_setup () {
       $exe_mysqld=         mtr_exe_exists ("$glob_basedir/sql/mysqld");
       $path_language=      mtr_path_exists("$glob_basedir/sql/share/english/");
       $path_charsetsdir=   mtr_path_exists("$glob_basedir/sql/share/charsets");
+      $exe_my_print_defaults=
+	mtr_exe_exists("$glob_basedir/extra/my_print_defaults");
     }
 
     if ( $glob_use_embedded_server )
@@ -952,6 +957,8 @@ sub executable_setup () {
     $exe_mysql_fix_system_tables=
       mtr_script_exists("$path_client_bindir/mysql_fix_privilege_tables",
 			"$glob_basedir/scripts/mysql_fix_privilege_tables");
+    $exe_my_print_defaults=
+      mtr_exe_exists("$path_client_bindir/my_print_defaults");
 
     $path_language=      mtr_path_exists("$glob_basedir/share/mysql/english/",
                                          "$glob_basedir/share/english/");
@@ -2303,6 +2310,7 @@ sub run_mysqltest ($) {
   $ENV{'MYSQL_FIX_SYSTEM_TABLES'}=  $cmdline_mysql_fix_system_tables;
   $ENV{'MYSQL_CLIENT_TEST'}=        $cmdline_mysql_client_test;
   $ENV{'CHARSETSDIR'}=              $path_charsetsdir;
+  $ENV{'MYSQL_MY_PRINT_DEFAULTS'}=  $exe_my_print_defaults;
 
   $ENV{'NDB_STATUS_OK'}=            $flag_ndb_status_ok;
   $ENV{'NDB_MGM'}=                  $exe_ndb_mgm;

mysql-test/mysql-test-run.sh

@@ -601,6 +601,7 @@ if [ x$SOURCE_DIST = x1 ] ; then
  CLIENT_BINDIR="$BASEDIR/client"
  MYSQLADMIN="$CLIENT_BINDIR/mysqladmin"
  WAIT_PID="$BASEDIR/extra/mysql_waitpid"
+ MYSQL_MY_PRINT_DEFAULTS="$BASEDIR/extra/my_print_defaults"
  MYSQL_MANAGER_CLIENT="$CLIENT_BINDIR/mysqlmanagerc"
  MYSQL_MANAGER="$BASEDIR/tools/mysqlmanager"
  MYSQL_MANAGER_PWGEN="$CLIENT_BINDIR/mysqlmanager-pwgen"
@@ -661,6 +662,7 @@ else
  MYSQL_BINLOG="$CLIENT_BINDIR/mysqlbinlog"
  MYSQLADMIN="$CLIENT_BINDIR/mysqladmin"
  WAIT_PID="$CLIENT_BINDIR/mysql_waitpid"
+ MYSQL_MY_PRINT_DEFAULTS="$CLIENT_BINDIR/my_print_defaults"
  MYSQL_MANAGER="$CLIENT_BINDIR/mysqlmanager"
  MYSQL_MANAGER_CLIENT="$CLIENT_BINDIR/mysqlmanagerc"
  MYSQL_MANAGER_PWGEN="$CLIENT_BINDIR/mysqlmanager-pwgen"
@@ -742,7 +744,7 @@ MYSQL_BINLOG="$MYSQL_BINLOG --no-defaults --local-load=$MYSQL_TMP_DIR $EXTRA_MYS
 MYSQL_FIX_SYSTEM_TABLES="$MYSQL_FIX_SYSTEM_TABLES --no-defaults --host=localhost --port=$MASTER_MYPORT --socket=$MASTER_MYSOCK --user=root --password=$DBPASSWD --basedir=$BASEDIR --bindir=$CLIENT_BINDIR --verbose"
 MYSQL="$MYSQL --no-defaults --host=localhost --port=$MASTER_MYPORT --socket=$MASTER_MYSOCK --user=root --password=$DBPASSWD"
 export MYSQL MYSQL_DUMP MYSQL_IMPORT MYSQL_BINLOG MYSQL_FIX_SYSTEM_TABLES
-export CLIENT_BINDIR MYSQL_CLIENT_TEST CHARSETSDIR
+export CLIENT_BINDIR MYSQL_CLIENT_TEST CHARSETSDIR MYSQL_MY_PRINT_DEFAULTS
 export NDB_TOOLS_DIR
 export NDB_MGM
 export NDB_BACKUP_DIR

mysql-test/r/mysqldump.result

@@ -1503,3 +1503,4 @@ select * from t1;
 a	b
 Osnabrück	Köln
 drop table t1;
+--fields-optionally-enclosed-by="

mysql-test/std_data/bug15328.cnf

@@ -0,0 +1,2 @@
+[mysqldump]
+fields-optionally-enclosed-by="

mysql-test/t/mysqldump.test

@@ -647,4 +647,12 @@ select * from t1;
 select * from t1;
 
 drop table t1;
+
+#
+# BUG#15328 Segmentation fault occured if my.cnf is invalid for escape sequence
+#
+
+--exec $MYSQL_MY_PRINT_DEFAULTS --defaults-extra-file=$MYSQL_TEST_DIR/std_data/bug15328.cnf mysqldump
+
+
 # End of 4.1 tests

mysys/default.c

@@ -579,7 +579,9 @@ static int search_default_file_with_ext(DYNAMIC_ARRAY *args, MEM_ROOT *alloc,
 	value_end=value;
 
       /* remove quotes around argument */
-      if ((*value == '\"' || *value == '\'') && *value == value_end[-1])
+      if ((*value == '\"' || *value == '\'') && /* First char is quote */
+          (value + 1 < value_end ) && /* String is longer than 1 */
+          *value == value_end[-1] ) /* First char is equal to last char */
       {
 	value++;
 	value_end--;