bk commit into 5.1 tree (anozdrin:1.2600) BUG#31111

[Alexander Nozdrin]

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5.1 repository of alik. When alik does a push these changes will
be propagated to the main repository and, within 24 hours after the
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ChangeSet@stripped, 2007-10-16 14:41:47+04:00, anozdrin@station. +7 -0
  Patch for BUG#31111: --read-only crashes MySQL (events fail to load).
  
  There actually were several problems here:
    - wrong lock type was acquired before reading mysql.event table;
    - Security_context::master_access attribute was not properly
      initialized in Security_context::init(), which led to differences
      in behavior with and without debug configure options.
    - if the server failed to load events from mysql.event, it:
      - forgot to close the mysql.event table, that led to the coredump,
        described in the bug report;
      - did not deinitialize the replication module, that lead to
        memory-lost warning on exit. 
  
  The patch is to fix all these problems:
    - Use READ-lock when loading events from the mysql.event table;
    - Initialize Security_context::master_access;
    - Close the mysql.event table in case something went wrong;
    - Deinitialize the replication module on exit.

  mysql-test/r/bug31111.result@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +3 -0
    Result file.

  mysql-test/r/bug31111.result@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +0 -0

  mysql-test/t/bug31111-master.opt@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +1 -0
    A test case for BUG#31111.

  mysql-test/t/bug31111-master.opt@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +0 -0

  mysql-test/t/bug31111.test@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +8 -0
    A test case for BUG#31111.

  mysql-test/t/bug31111.test@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +0 -0

  sql/event_db_repository.cc@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +6 -0
    Close tables if something went wrong in simple_open_n_lock_tables().

  sql/events.cc@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +1 -1
    Use READ-lock for loading events.

  sql/mysqld.cc@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +3 -0
    If something went wrong with event loading, we the replication
    module should be deinitialized prior to general exit procedure.

  sql/sql_class.cc@stripped, 2007-10-16 14:41:45+04:00, anozdrin@station. +1 -0
    Initialize Security_context::master_acces.

diff -Nrup a/mysql-test/r/bug31111.result b/mysql-test/r/bug31111.result
--- /dev/null	Wed Dec 31 16:00:00 196900
+++ b/mysql-test/r/bug31111.result	2007-10-16 14:41:45 +04:00
@@ -0,0 +1,3 @@
+SELECT @@global.read_only;
+@@global.read_only
+1
diff -Nrup a/mysql-test/t/bug31111-master.opt b/mysql-test/t/bug31111-master.opt
--- /dev/null	Wed Dec 31 16:00:00 196900
+++ b/mysql-test/t/bug31111-master.opt	2007-10-16 14:41:45 +04:00
@@ -0,0 +1 @@
+--read-only
diff -Nrup a/mysql-test/t/bug31111.test b/mysql-test/t/bug31111.test
--- /dev/null	Wed Dec 31 16:00:00 196900
+++ b/mysql-test/t/bug31111.test	2007-10-16 14:41:45 +04:00
@@ -0,0 +1,8 @@
+#
+# BUG#31111: --read-only crashes MySQL (events fail to load).
+#
+# It actually does not matter what SQL statements are here. The thing is being
+# tested is that the server is able to start.
+#
+
+SELECT @@global.read_only;
diff -Nrup a/sql/event_db_repository.cc b/sql/event_db_repository.cc
--- a/sql/event_db_repository.cc	2007-08-25 12:43:10 +04:00
+++ b/sql/event_db_repository.cc	2007-10-16 14:41:45 +04:00
@@ -525,6 +525,9 @@ Event_db_repository::fill_schema_events(
   - whether this open mode would work under LOCK TABLES, or inside a
   stored function or trigger.
 
+  Note, if the table can not be open, this operation will clean out all
+  table-related objects from the memory.
+
   @param[in]  thd  Thread context
   @param[in]  lock_type  How to lock the table
   @param[out] table  We will store the open table here
@@ -544,7 +547,10 @@ Event_db_repository::open_event_table(TH
   tables.init_one_table("mysql", "event", lock_type);
 
   if (simple_open_n_lock_tables(thd, &tables))
+  {
+    close_thread_tables(thd, FALSE, FALSE);
     DBUG_RETURN(TRUE);
+  }
 
   *table= tables.table;
   tables.table->use_all_columns();
diff -Nrup a/sql/events.cc b/sql/events.cc
--- a/sql/events.cc	2007-08-15 19:08:40 +04:00
+++ b/sql/events.cc	2007-10-16 14:41:45 +04:00
@@ -1128,7 +1128,7 @@ Events::load_events_from_db(THD *thd)
   DBUG_ENTER("Events::load_events_from_db");
   DBUG_PRINT("enter", ("thd: 0x%lx", (long) thd));
 
-  if (db_repository->open_event_table(thd, TL_WRITE, &table))
+  if (db_repository->open_event_table(thd, TL_READ, &table))
   {
     sql_print_error("Event Scheduler: Failed to open table mysql.event");
     DBUG_RETURN(TRUE);
diff -Nrup a/sql/mysqld.cc b/sql/mysqld.cc
--- a/sql/mysqld.cc	2007-08-28 11:02:53 +04:00
+++ b/sql/mysqld.cc	2007-10-16 14:41:45 +04:00
@@ -3930,7 +3930,10 @@ we force server id to 2, but this MySQL 
   create_maintenance_thread();
 
   if (Events::init(opt_noacl))
+  {
+    end_slave();
     unireg_abort(1);
+  }
 
   sql_print_information(ER(ER_STARTUP),my_progname,server_version,
                         ((unix_sock == INVALID_SOCKET) ? (char*) ""
diff -Nrup a/sql/sql_class.cc b/sql/sql_class.cc
--- a/sql/sql_class.cc	2007-10-15 16:42:39 +04:00
+++ b/sql/sql_class.cc	2007-10-16 14:41:45 +04:00
@@ -2404,6 +2404,7 @@ void Security_context::init()
   host= user= priv_user= ip= 0;
   host_or_ip= "connecting host";
   priv_host[0]= '\0';
+  master_access= 0;
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   db_access= NO_ACCESS;
 #endif