mdev-200 set session dbug resets the output to stderr.

it makes "./mtr --debug" unusable

revert the mysql fix for bug#46165.
implement shared FILE's with reference counting

mysql-test/r/error_simulation.result

@@ -13,7 +13,7 @@ INSERT INTO t1 VALUES
 ('AAAAAAAAAH','AAAAAAAAAH'), ('AAAAAAAAAI','AAAAAAAAAI'),
 ('AAAAAAAAAJ','AAAAAAAAAJ'), ('AAAAAAAAAK','AAAAAAAAAK');
 set tmp_table_size=1024;
-set session debug_dbug="d,raise_error";
+set session debug_dbug="+d,raise_error";
 SELECT MAX(a) FROM t1 GROUP BY a,b;
 ERROR 23000: Can't write; duplicate key in table 'tmp_table'
 set tmp_table_size=default;

mysql-test/suite/sys_vars/r/debug_dbug_func.result

@@ -51,13 +51,13 @@ End of 5.1 tests
 SET @old_globaldebug = @@global.debug;
 SET @old_sessiondebug= @@session.debug;
 # Test 1 - Bug test case, single connection
-SET GLOBAL  debug_dbug= '+O,../../log/bug46165.1.trace';
+SET GLOBAL  debug_dbug= '+O,MYSQL_TMP_DIR/bug46165.1.trace';
 SET SESSION debug_dbug= '-d:-t:-i';
 SET GLOBAL  debug_dbug= '';
 SET SESSION debug_dbug= '';
 # Test 2 - Bug test case, two connections
 # Connection default
-SET GLOBAL  debug_dbug= '+O,../../log/bug46165.2.trace';
+SET GLOBAL  debug_dbug= '+O,MYSQL_TMP_DIR/bug46165.2.trace';
 SET SESSION debug_dbug= '-d:-t:-i';
 # Connection con1
 SET GLOBAL  debug_dbug= '';
@@ -68,12 +68,21 @@ SET SESSION debug_dbug= '';
 SET GLOBAL  debug_dbug= '';
 # Test 3 - Active session trace file on disconnect
 # Connection con1
-SET GLOBAL  debug_dbug= '+O,../../log/bug46165.3.trace';
-SET SESSION debug_dbug= '-d:-t:-i';
+SET GLOBAL  debug_dbug= '+O,MYSQL_TMP_DIR/bug46165.3.trace';
+SELECT @@global.debug_dbug, @@session.debug_dbug;
+@@global.debug_dbug	@@session.debug_dbug
+O,MYSQL_TMP_DIR/bug46165.3.trace	O,MYSQL_TMP_DIR/bug46165.3.trace
+SET SESSION debug_dbug= '+T';
+SELECT @@global.debug_dbug, @@session.debug_dbug;
+@@global.debug_dbug	@@session.debug_dbug
+O,MYSQL_TMP_DIR/bug46165.3.trace	O,MYSQL_TMP_DIR/bug46165.3.trace:T
 SET GLOBAL  debug_dbug= '';
+SELECT @@global.debug_dbug, @@session.debug_dbug;
+@@global.debug_dbug	@@session.debug_dbug
+	O,MYSQL_TMP_DIR/bug46165.3.trace:T
 # Test 4 - Active session trace file on two connections
 # Connection default
-SET GLOBAL  debug_dbug= '+O,../../log/bug46165.4.trace';
+SET GLOBAL  debug_dbug= '+O,MYSQL_TMP_DIR/bug46165.4.trace';
 SET SESSION debug_dbug= '-d:-t:-i';
 # Connection con1
 SET SESSION debug_dbug= '-d:-t:-i';
@@ -84,8 +93,8 @@ SET SESSION debug_dbug= '';
 # Connection con1
 # Connection default
 # Test 5 - Different trace files
-SET SESSION debug_dbug= '+O,../../log/bug46165.5.trace';
-SET SESSION debug_dbug= '+O,../../log/bug46165.6.trace';
+SET SESSION debug_dbug= '+O,MYSQL_TMP_DIR/bug46165.5.trace';
+SET SESSION debug_dbug= '+O,MYSQL_TMP_DIR/bug46165.6.trace';
 SET SESSION debug_dbug= '-O';
 SET GLOBAL  debug_dbug= @old_globaldebug;
 SET SESSION debug_dbug= @old_sessiondebug;

mysql-test/suite/sys_vars/t/debug_dbug_func.test

@@ -59,7 +59,8 @@ SET @old_globaldebug = @@global.debug;
 SET @old_sessiondebug= @@session.debug;
 
 --echo # Test 1 - Bug test case, single connection
-SET GLOBAL  debug_dbug= '+O,../../log/bug46165.1.trace';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval SET GLOBAL  debug_dbug= '+O,$MYSQL_TMP_DIR/bug46165.1.trace';
 SET SESSION debug_dbug= '-d:-t:-i';
 
 SET GLOBAL  debug_dbug= '';
@@ -68,7 +69,8 @@ SET SESSION debug_dbug= '';
 --echo # Test 2 - Bug test case, two connections
 --echo # Connection default
 connection default;
-SET GLOBAL  debug_dbug= '+O,../../log/bug46165.2.trace';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval SET GLOBAL  debug_dbug= '+O,$MYSQL_TMP_DIR/bug46165.2.trace';
 SET SESSION debug_dbug= '-d:-t:-i';
 
 --echo # Connection con1
@@ -89,16 +91,24 @@ SET GLOBAL  debug_dbug= '';
 --echo # Test 3 - Active session trace file on disconnect
 --echo # Connection con1
 connect (con1, localhost, root);
-SET GLOBAL  debug_dbug= '+O,../../log/bug46165.3.trace';
-SET SESSION debug_dbug= '-d:-t:-i';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval SET GLOBAL  debug_dbug= '+O,$MYSQL_TMP_DIR/bug46165.3.trace';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+SELECT @@global.debug_dbug, @@session.debug_dbug;
+SET SESSION debug_dbug= '+T';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+SELECT @@global.debug_dbug, @@session.debug_dbug;
 SET GLOBAL  debug_dbug= '';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+SELECT @@global.debug_dbug, @@session.debug_dbug;
 disconnect con1;
 --source include/wait_until_disconnected.inc
 
 --echo # Test 4 - Active session trace file on two connections
 --echo # Connection default
 connection default;
-SET GLOBAL  debug_dbug= '+O,../../log/bug46165.4.trace';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval SET GLOBAL  debug_dbug= '+O,$MYSQL_TMP_DIR/bug46165.4.trace';
 SET SESSION debug_dbug= '-d:-t:-i';
 
 --echo # Connection con1
@@ -118,8 +128,10 @@ disconnect con1;
 connection default;
 
 --echo # Test 5 - Different trace files
-SET SESSION debug_dbug= '+O,../../log/bug46165.5.trace';
-SET SESSION debug_dbug= '+O,../../log/bug46165.6.trace';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval SET SESSION debug_dbug= '+O,$MYSQL_TMP_DIR/bug46165.5.trace';
+--replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR
+eval SET SESSION debug_dbug= '+O,$MYSQL_TMP_DIR/bug46165.6.trace';
 SET SESSION debug_dbug= '-O';
 
 SET GLOBAL  debug_dbug= @old_globaldebug;

mysql-test/t/error_simulation.test

@@ -23,7 +23,7 @@ set tmp_table_size=1024;
 
 # Set debug flag so an error is returned when
 # tmp table in query is converted from heap to myisam
-set session debug_dbug="d,raise_error";
+set session debug_dbug="+d,raise_error";
 
 --replace_regex /in table '[^']+'/in table 'tmp_table'/
 --error ER_DUP_KEY