MWL#182: Explain running statements: address review feedback

- Fix the year in Monty Program Ab copyrights in the new files.
- Fix permissions handling so that SHOW EXPLAIN's handling is the 
  same as SHOW PROCESSLIST's.

2 files changed, 109 insertions, 3 deletions

diff --git a/mysql-test/r/show_explain.result b/mysql-test/r/show_explain.result
index 07bcb29a7ea..a4097b9d65e 100644
--- a/mysql-test/r/show_explain.result
+++ b/mysql-test/r/show_explain.result
@@ -728,4 +728,49 @@ a
 2
 set debug_dbug='';
 drop table t1,t3,t4;
+#
+# ----------  SHOW EXPLAIN and permissions -----------------
+#
+grant ALL on test.* to test2@localhost;
+#
+#  First, make sure that user 'test2' cannot do SHOW EXPLAIN on us
+#
+set debug_dbug='d,show_explain_probe_join_exec_start';
+select * from t0 where a < 3;
+show explain for $thr2;
+ERROR 42000: Access denied; you need (at least one of) the PROCESSLIST privilege(s) for this operation
+show explain for $thr2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
+Warnings:
+Note	1003	select * from t0 where a < 3
+a
+0
+1
+2
+set debug_dbug='';
+#
+# Unfortunately, our test setup doesn't allow to check that test2
+# can do SHOW EXPLAIN on his own queries. This is because SET debug_dbug
+# requires SUPER privilege. Giving SUPER to test2 will make the test
+# meaningless
+#
+#
+# Now, grant test2 a PROCESSLIST permission, and see that he's able to observe us 
+#
+grant process on *.* to test2@localhost;
+set debug_dbug='d,show_explain_probe_join_exec_start';
+select * from t0 where a < 3;
+show explain for $thr2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	10	Using where
+Warnings:
+Note	1003	select * from t0 where a < 3
+a
+0
+1
+2
+set debug_dbug='';
+revoke all privileges on test.* from test2@localhost;
+drop user test2@localhost;
 drop table t0;
diff --git a/mysql-test/t/show_explain.test b/mysql-test/t/show_explain.test
index ffd2c25dfd9..5db6b96d93b 100644
--- a/mysql-test/t/show_explain.test
+++ b/mysql-test/t/show_explain.test
@@ -727,10 +727,71 @@ reap;
 set debug_dbug='';
 
 drop table t1,t3,t4;
+
+--echo #
+--echo # ----------  SHOW EXPLAIN and permissions -----------------
+--echo #
+grant ALL on test.* to test2@localhost;
+
+connect (con2, localhost, test2,,);
+connection con1;
+
+--echo #
+--echo #  First, make sure that user 'test2' cannot do SHOW EXPLAIN on us
+--echo #
+set debug_dbug='d,show_explain_probe_join_exec_start';
+send
+select * from t0 where a < 3;
+
+connection default;
+--source include/wait_condition.inc
+
+connection con2;
+--error ER_SPECIFIC_ACCESS_DENIED_ERROR
+evalp show explain for $thr2;
+
+connection default;
+evalp show explain for $thr2;
+
+connection con1;
+reap;
+set debug_dbug='';
+
+--echo #
+--echo # Unfortunately, our test setup doesn't allow to check that test2
+--echo # can do SHOW EXPLAIN on his own queries. This is because SET debug_dbug
+--echo # requires SUPER privilege. Giving SUPER to test2 will make the test
+--echo # meaningless
+--echo #
+
+--echo #
+--echo # Now, grant test2 a PROCESSLIST permission, and see that he's able to observe us 
+--echo #
+disconnect con2;
+grant process on *.* to test2@localhost;
+connect (con2, localhost, test2,,);
+connection con1;
+
+set debug_dbug='d,show_explain_probe_join_exec_start';
+send
+select * from t0 where a < 3;
+
+connection default;
+--source include/wait_condition.inc
+
+connection con2;
+evalp show explain for $thr2;
+
+connection con1;
+reap;
+set debug_dbug='';
+
+
+
+revoke all privileges on test.* from test2@localhost;
+drop user test2@localhost;
+
 ## TODO: Test this: have several SHOW EXPLAIN requests be queued up for a
 ##       thread and served together.
 
-## TODO: SHOW EXPLAIN while the primary query is running EXPLAIN EXTENDED/PARTITIONS
-##
-
 drop table t0;