Fixed BUG#4934: Caching issue with stored procedures.

  ...and added new test file, sp-threads, for multiple connection tests
  (apart from the security tests that are in sp-security).

mysql-test/r/sp-threads.result

+use test;
+drop table if exists t1;
+create table t1 (s1 int, s2 int, s3 int);
+create procedure bug4934()
+begin
+insert into t1 values (1,0,1);
+end//
+use test;
+call bug4934();
+select * from t1;
+s1	s2	s3
+1	0	1
+drop table t1;
+create table t1 (s1 int, s2 int, s3 int);
+drop procedure bug4934;
+create procedure bug4934()
+begin
+end//
+select * from t1;
+s1	s2	s3
+call bug4934();
+select * from t1;
+s1	s2	s3
+drop table t1;
+drop procedure bug4934;

mysql-test/t/sp-threads.test

+#
+# Testing stored procedures with multiple connections
+#
+
+connect (con1root,localhost,root,,);
+connect (con2root,localhost,root,,);
+
+connection con1root;
+use test;
+
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+create table t1 (s1 int, s2 int, s3 int);
+
+delimiter //; 
+create procedure bug4934()
+begin
+   insert into t1 values (1,0,1);
+end//
+delimiter ;//
+
+
+connection con2root;
+use test;
+
+call bug4934();
+select * from t1;
+
+
+connection con1root;
+
+drop table t1;
+create table t1 (s1 int, s2 int, s3 int);
+
+drop procedure bug4934;
+delimiter //; 
+create procedure bug4934()
+begin
+end//
+delimiter ;//
+
+
+connection con2root;
+
+select * from t1;
+call bug4934();
+select * from t1;
+
+connection con1root;
+
+drop table t1;
+drop procedure bug4934;
+

sql/sp.cc

@@ -722,11 +722,14 @@ int
 sp_drop_procedure(THD *thd, sp_name *name)
 {
   int ret;
+  bool found;
   DBUG_ENTER("sp_drop_procedure");
   DBUG_PRINT("enter", ("name: %*s", name->m_name.length, name->m_name.str));
 
-  sp_cache_remove(&thd->sp_proc_cache, name);
+  found= sp_cache_remove(&thd->sp_proc_cache, name);
   ret= db_drop_routine(thd, TYPE_ENUM_PROCEDURE, name);
+  if (!found && !ret)
+    sp_cache_invalidate();
   DBUG_RETURN(ret);
 }
 
@@ -737,12 +740,15 @@ sp_update_procedure(THD *thd, sp_name *name,
 		    st_sp_chistics *chistics)
 {
   int ret;
+  bool found;
   DBUG_ENTER("sp_update_procedure");
   DBUG_PRINT("enter", ("name: %*s", name->m_name.length, name->m_name.str));
 
-  sp_cache_remove(&thd->sp_proc_cache, name);
+  found= sp_cache_remove(&thd->sp_proc_cache, name);
   ret= db_update_routine(thd, TYPE_ENUM_PROCEDURE, name,
 			 newname, newnamelen, chistics);
+  if (!found && !ret)
+    sp_cache_invalidate();
   DBUG_RETURN(ret);
 }
 
@@ -814,11 +820,14 @@ int
 sp_drop_function(THD *thd, sp_name *name)
 {
   int ret;
+  bool found;
   DBUG_ENTER("sp_drop_function");
   DBUG_PRINT("enter", ("name: %*s", name->m_name.length, name->m_name.str));
 
-  sp_cache_remove(&thd->sp_func_cache, name);
+  found= sp_cache_remove(&thd->sp_func_cache, name);
   ret= db_drop_routine(thd, TYPE_ENUM_FUNCTION, name);
+  if (!found && !ret)
+    sp_cache_invalidate();
   DBUG_RETURN(ret);
 }
 
@@ -829,12 +838,15 @@ sp_update_function(THD *thd, sp_name *name,
 		    st_sp_chistics *chistics)
 {
   int ret;
+  bool found;
   DBUG_ENTER("sp_update_procedure");
   DBUG_PRINT("enter", ("name: %*s", name->m_name.length, name->m_name.str));
 
-  sp_cache_remove(&thd->sp_func_cache, name);
+  found= sp_cache_remove(&thd->sp_func_cache, name);
   ret= db_update_routine(thd, TYPE_ENUM_FUNCTION, name,
 			 newname, newnamelen, chistics);
+  if (!found && !ret)
+    sp_cache_invalidate();
   DBUG_RETURN(ret);
 }