mysqltest: Write command to be executed to the log BEFORE executing the command.

Fixed race condition in event that could cause hang when stopping event scheduler with SET GLOBAL event_scheduler=OFF 

client/mysqltest.cc:
  Write command to be executed to the log BEFORE executing the command.
  This makes it easier to debug crashes as the log will contain the fatal command.
mysql-test/r/mysqltest.result:
  Updated results (we now get more things logged)
sql/event_queue.cc:
  Fixed race condition in event that could cause hang when stopping event scheduler with SET GLOBAL event_scheduler=OFF.
  The reason was that a kill signal could be sent between last check of thd->killed and before thd->enter_cond() in which case the signal
  would be missed and we would be stuck in Event_scheduler::stop() forever.

client/mysqltest.cc

@@ -601,6 +601,10 @@ class LogFile {
       DBUG_VOID_RETURN;
     DBUG_ASSERT(ds->str);
 
+#ifdef EXTRA_DEBUG
+    DBUG_PRINT("QQ", ("str: %*s", (int) ds->length, ds->str));
+#endif
+
     if (fwrite(ds->str, 1, ds->length, m_file) != ds->length)
       die("Failed to write %lu bytes to '%s', errno: %d",
           (unsigned long)ds->length, m_file_name, errno);
@@ -1288,6 +1292,7 @@ void die(const char *fmt, ...)
   DBUG_ENTER("die");
   DBUG_PRINT("enter", ("start_lineno: %d", start_lineno));
 
+  fflush(stdout);
   /* Print the error message */
   fprintf(stderr, "mysqltest: ");
   if (cur_file && cur_file != file_stack)
@@ -1374,6 +1379,7 @@ void verbose_msg(const char *fmt, ...)
   if (!verbose)
     DBUG_VOID_RETURN;
 
+  fflush(stdout);
   va_start(args, fmt);
   fprintf(stderr, "mysqltest: ");
   if (cur_file && cur_file != file_stack)
@@ -1384,6 +1390,7 @@ void verbose_msg(const char *fmt, ...)
   vfprintf(stderr, fmt, args);
   fprintf(stderr, "\n");
   va_end(args);
+  fflush(stderr);
 
   DBUG_VOID_RETURN;
 }
@@ -1468,6 +1475,8 @@ static int run_command(char* cmd,
   char buf[512]= {0};
   FILE *res_file;
   int error;
+  DBUG_ENTER("run_command");
+  DBUG_PRINT("enter", ("cmd: %s", cmd));
 
   if (!(res_file= popen(cmd, "r")))
     die("popen(\"%s\", \"r\") failed", cmd);
@@ -1488,7 +1497,7 @@ static int run_command(char* cmd,
   }
 
   error= pclose(res_file);
-  return WEXITSTATUS(error);
+  DBUG_RETURN(WEXITSTATUS(error));
 }
 
 
@@ -7545,6 +7554,15 @@ void run_query(struct st_connection *cn, struct st_command *command, int flags)
     dynstr_append_mem(ds, "\n", 1);
   }
 
+  /*
+    Write the command to the result file before we execute the query
+    This is needed to be able to analyse the log if something goes
+    wrong
+  */
+  log_file.write(&ds_res);
+  log_file.flush();
+  dynstr_set(&ds_res, 0);
+
   if (view_protocol_enabled &&
       complete_query &&
       match_re(&view_re, query))

mysql-test/r/mysqltest.result

@@ -8,16 +8,19 @@ otto
 select otto from (select 1 as otto) as t1;
 otto
 1
+select friedrich from (select 1 as otto) as t1;
 mysqltest: At line 1: query 'select friedrich from (select 1 as otto) as t1' failed: 1054: Unknown column 'friedrich' in 'field list'
 select friedrich from (select 1 as otto) as t1;
 ERROR 42S22: Unknown column 'friedrich' in 'field list'
 select otto from (select 1 as otto) as t1;
 otto
 1
+select otto from (select 1 as otto) as t1;
 mysqltest: At line 1: query 'select otto from (select 1 as otto) as t1' succeeded - should have failed with sqlstate 42S22...
 mysqltest: At line 1: expecting a SQL-state (00000) from query 'remove_file MYSQLTEST_VARDIR/tmp/test_nonexistent.tmp' which cannot produce one...
 select friedrich from (select 1 as otto) as t1;
 ERROR 42S22: Unknown column 'friedrich' in 'field list'
+select friedrich from (select 1 as otto) as t1;
 mysqltest: At line 1: query 'select friedrich from (select 1 as otto) as t1' failed with wrong sqlstate 42S22: 'Unknown column 'friedrich' in 'field list'', instead of 00000...
 select otto from (select 1 as otto) as t1;
 otto
@@ -135,6 +138,7 @@ ERROR 42S02: Table 'test.t1' doesn't exist
 select 1146 as "after_!errno_masked_error" ;
 after_!errno_masked_error
 1146
+select 3 from t1;
 mysqltest: At line 1: query 'select 3 from t1' failed with wrong errno 1146: 'Table 'test.t1' doesn't exist', instead of 1000...
 garbage ;
 ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'garbage' at line 1
@@ -143,6 +147,7 @@ after_--enable_abort_on_error
 1064
 select 3 from t1 ;
 ERROR 42S02: Table 'test.t1' doesn't exist
+select 3 from t1;
 mysqltest: At line 1: query 'select 3 from t1' failed with wrong errno 1146: 'Table 'test.t1' doesn't exist', instead of 1064...
 hello
 hello
@@ -336,6 +341,7 @@ included from MYSQLTEST_VARDIR/tmp/recursive.sql at line 1:
 included from MYSQLTEST_VARDIR/tmp/recursive.sql at line 1:
 included from MYSQLTEST_VARDIR/tmp/recursive.sql at line 1:
 At line 1: Source directives are nesting too deep
+garbage ;
 mysqltest: In included file "MYSQLTEST_VARDIR/tmp/error.sql": 
 included from MYSQLTEST_VARDIR/tmp/error.sql at line 1:
 At line 1: query 'garbage ' failed: 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'garbage' at line 1
@@ -440,6 +446,7 @@ mysqltest: At line 1: missing ')' in while
 mysqltest: At line 1: Missing '{' after while. Found "dec $i"
 mysqltest: At line 1: Stray '}' - end of block before beginning
 mysqltest: At line 1: Stray 'end' command - end of block before beginning
+{;
 mysqltest: At line 1: query '{' failed: 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '{' at line 1
 mysqltest: At line 1: Missing '{' after while. Found "echo hej"
 mysqltest: At line 3: Missing end of block
@@ -533,6 +540,10 @@ this will be executed
 this will be executed
 mysqltest: The test didn't produce any output
 Failing multi statement query
+create table t1 (a int primary key);
+insert into t1 values (1);
+select 'select-me';
+insertz 'error query'||||
 mysqltest: At line 3: query 'create table t1 (a int primary key);
 insert into t1 values (1);
 select 'select-me';
@@ -603,8 +614,8 @@ Abcd
 select * from t1;;
 f1
 Abcd
-mysqltest: At line 2: Cannot run query on connection between send and reap
 select * from t1;;
+mysqltest: At line 2: Cannot run query on connection between send and reap
 drop table t1;
 mysqltest: At line 1: Missing required argument 'filename' to command 'remove_file'
 mysqltest: At line 1: Missing required argument 'directory' to command 'remove_files_wildcard'

sql/event_queue.cc

@@ -734,12 +734,14 @@ Event_queue::cond_wait(THD *thd, struct timespec *abstime, const char* msg,
 
   thd->enter_cond(&COND_queue_state, &LOCK_event_queue, msg);
 
-  DBUG_PRINT("info", ("pthread_cond_%swait", abstime? "timed":""));
-  if (!abstime)
-    pthread_cond_wait(&COND_queue_state, &LOCK_event_queue);
-  else
-    pthread_cond_timedwait(&COND_queue_state, &LOCK_event_queue, abstime);
-
+  if (!thd->killed)
+  {
+    DBUG_PRINT("info", ("pthread_cond_%swait", abstime ? "timed" : ""));
+    if (!abstime)
+      pthread_cond_wait(&COND_queue_state, &LOCK_event_queue);
+    else
+      pthread_cond_timedwait(&COND_queue_state, &LOCK_event_queue, abstime);
+  }
   mutex_last_locked_in_func= func;
   mutex_last_locked_at_line= line;
   mutex_queue_data_locked= TRUE;