diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/item_create.cc mysql-5.0.25-nightly-20060823.caller/sql/item_create.cc
--- mysql-5.0.25-nightly-20060823.orig/sql/item_create.cc	2006-08-22 23:09:17.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/item_create.cc	2006-10-01 16:01:20.000000000 -0700
@@ -64,6 +64,21 @@
   return new Item_func_bit_count(a);
 }
 
+Item *create_func_caller(Item *a)
+{
+  return new Item_func_caller(a);
+}
+
+Item *create_func_caller_depth()
+{
+  return new Item_func_caller_depth();
+}
+
+Item *create_func_caller_ws(Item *a, Item *b)
+{
+  return new Item_func_caller_ws(a, b);
+}
+
 Item *create_func_ceiling(Item* a)
 {
   return new Item_func_ceiling(a);
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/item_create.h mysql-5.0.25-nightly-20060823.caller/sql/item_create.h
--- mysql-5.0.25-nightly-20060823.orig/sql/item_create.h	2006-08-22 23:09:16.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/item_create.h	2006-10-01 16:00:17.000000000 -0700
@@ -25,6 +25,9 @@
 Item *create_func_bin(Item* a);
 Item *create_func_bit_count(Item* a);
 Item *create_func_bit_length(Item* a);
+Item *create_func_caller(Item *a);
+Item *create_func_caller_depth();
+Item *create_func_caller_ws(Item *a, Item *b);
 Item *create_func_coercibility(Item* a);
 Item *create_func_ceiling(Item* a);
 Item *create_func_char_length(Item* a);
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/item_func.cc mysql-5.0.25-nightly-20060823.caller/sql/item_func.cc
--- mysql-5.0.25-nightly-20060823.orig/sql/item_func.cc	2006-08-22 23:09:21.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/item_func.cc	2006-10-01 16:08:49.000000000 -0700
@@ -4688,6 +4688,22 @@
   return ull->thread_id;
 }
 
+longlong Item_func_caller_depth::val_int()
+{
+  DBUG_ASSERT(fixed == 1);
+  THD *thd= current_thd;
+
+  uint32 depth;
+  Query *query;
+  List_iterator<Query> it(thd->query_stack);
+
+  if(thd->query_stack.is_empty())
+    return 0;
+
+  for(depth=0; (query= it++); depth++)  { }
+
+  return depth;
+}
 
 longlong Item_func_row_count::val_int()
 {
@@ -4697,7 +4713,6 @@
   return thd->row_count_func;
 }
 
-
 Item_func_sp::Item_func_sp(Name_resolution_context *context_arg, sp_name *name)
   :Item_func(), context(context_arg), m_name(name), m_sp(NULL),
    result_field(NULL)
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/item_func.h mysql-5.0.25-nightly-20060823.caller/sql/item_func.h
--- mysql-5.0.25-nightly-20060823.orig/sql/item_func.h	2006-08-22 23:09:19.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/item_func.h	2006-10-01 16:04:03.000000000 -0700
@@ -1370,6 +1370,16 @@
 };
 
 
+class Item_func_caller_depth :public Item_int_func
+{
+public:
+  Item_func_caller_depth() :Item_int_func() {}
+  longlong val_int();
+  const char *func_name() const { return "caller_depth"; }
+  void fix_length_and_dec() { decimals= 0; maybe_null=0; }
+};
+
+
 class Item_func_row_count :public Item_int_func
 {
 public:
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/item_strfunc.cc mysql-5.0.25-nightly-20060823.caller/sql/item_strfunc.cc
--- mysql-5.0.25-nightly-20060823.orig/sql/item_strfunc.cc	2006-08-22 23:09:19.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/item_strfunc.cc	2006-10-01 17:07:58.000000000 -0700
@@ -119,6 +119,90 @@
 	  (longlong) 0);
 }
 
+String *Item_func_caller::val_str(String *str)
+{
+  THD *thd= current_thd;
+  uint32 cur= 1;
+  uint32 pos= 0;
+  Query *query;
+  List_iterator<Query> it(thd->query_stack);
+
+  if(arg_count)
+    pos= args[0]->val_int();
+
+  if(pos && thd->query_stack.is_empty())
+    goto invalid_stack;
+
+  null_value= 0;
+  if(pos == 0)
+  {
+    str->set(thd->query, thd->query_length, system_charset_info);
+  } else {
+    while((query= it++) && (++cur <= pos)) { }
+    if(!query)
+      goto invalid_stack;
+    str->set(query->query, query->query_length, system_charset_info);
+  }
+  return str;
+
+ invalid_stack:
+  null_value= 1;
+  return 0;
+}
+
+void Item_func_caller::fix_length_and_dec()
+{
+  //max_length= current_thd->;
+  maybe_null= 1;
+}
+
+
+String *Item_func_caller_ws::val_str(String *str)
+{
+  uint32 cur= 1;
+  uint32 pos= 0;
+  Query *query;
+  List_iterator<Query> it(current_thd->query_stack);
+  String sep, *psep;
+
+  if(arg_count) 
+  {
+    psep= args[0]->val_str(&sep);
+    pos= args[1]->val_int();
+  }
+
+  if(pos && current_thd->query_stack.is_empty())
+    goto invalid_stack;
+
+  null_value= 0;
+  if(pos == 0)
+  {
+    str->set(current_thd->query, current_thd->query_length, system_charset_info);
+  } else {
+    while((query= it++) && (++cur <= pos)) { }
+    if(!query)
+      goto invalid_stack;
+    str->set(query->query, query->query_length, system_charset_info);
+  }
+
+  while(query= it++)
+  {
+    str->append(psep->ptr());
+    str->append(query->query);
+  }
+  return str;
+
+ invalid_stack:
+  null_value= 1;
+  return 0;
+}
+
+void Item_func_caller_ws::fix_length_and_dec()
+{
+  //max_length= current_thd->;
+  maybe_null= 1;
+}
+
 
 String *Item_func_md5::val_str(String *str)
 {
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/item_strfunc.h mysql-5.0.25-nightly-20060823.caller/sql/item_strfunc.h
--- mysql-5.0.25-nightly-20060823.orig/sql/item_strfunc.h	2006-08-22 23:09:17.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/item_strfunc.h	2006-10-01 16:02:15.000000000 -0700
@@ -39,6 +39,27 @@
   String *check_well_formed_result(String *str);
 };
 
+class Item_func_caller :public Item_str_func
+{
+  String tmp_value;
+public:
+  Item_func_caller(Item *a) :Item_str_func(a) {}
+  String *val_str(String *);
+  void fix_length_and_dec();
+  const char *func_name() const { return "caller"; }
+};
+
+class Item_func_caller_ws :public Item_str_func
+{
+  String tmp_value;
+public:
+  Item_func_caller_ws(Item *a, Item *b) :Item_str_func(a, b) {}
+  String *val_str(String *);
+  void fix_length_and_dec();
+  const char *func_name() const { return "caller_ws"; }
+};
+
+
 class Item_func_md5 :public Item_str_func
 {
   String tmp_value;
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/lex.h mysql-5.0.25-nightly-20060823.caller/sql/lex.h
--- mysql-5.0.25-nightly-20060823.orig/sql/lex.h	2006-08-22 23:09:20.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/lex.h	2006-10-01 16:00:27.000000000 -0700
@@ -564,6 +564,9 @@
   { "BIT_OR",		SYM(BIT_OR)},
   { "BIT_AND",		SYM(BIT_AND)},
   { "BIT_XOR",		SYM(BIT_XOR)},
+  { "CALLER",           F_SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_caller)},
+  { "CALLER_DEPTH",     F_SYM(FUNC_ARG0),0,CREATE_FUNC(create_func_caller_depth)},
+  { "CALLER_WS",        F_SYM(FUNC_ARG2),0,CREATE_FUNC(create_func_caller_ws)},
   { "CAST",		SYM(CAST_SYM)},
   { "CEIL",		F_SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_ceiling)},
   { "CEILING",		F_SYM(FUNC_ARG1),0,CREATE_FUNC(create_func_ceiling)},
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/sp_head.cc mysql-5.0.25-nightly-20060823.caller/sql/sp_head.cc
--- mysql-5.0.25-nightly-20060823.orig/sql/sp_head.cc	2006-08-22 23:09:17.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/sp_head.cc	2006-10-01 12:08:32.000000000 -0700
@@ -2419,14 +2419,11 @@
 int
 sp_instr_stmt::execute(THD *thd, uint *nextp)
 {
-  char *query;
-  uint32 query_length;
   int res;
   DBUG_ENTER("sp_instr_stmt::execute");
   DBUG_PRINT("info", ("command: %d", m_lex_keeper.sql_command()));
 
-  query= thd->query;
-  query_length= thd->query_length;
+  thd->query_stack.push_front(new Query(thd->query, thd->query_length));
   if (!(res= alloc_query(thd, m_query.str, m_query.length+1)) &&
       !(res=subst_spvars(thd, this, &m_query)))
   {
@@ -2442,8 +2439,7 @@
     }
     else
       *nextp= m_ip+1;
-    thd->query= query;
-    thd->query_length= query_length;
+    thd->query_stack.pop()->get(&thd->query, &thd->query_length);
   }
   DBUG_RETURN(res);
 }
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/sql_class.cc mysql-5.0.25-nightly-20060823.caller/sql/sql_class.cc
--- mysql-5.0.25-nightly-20060823.orig/sql/sql_class.cc	2006-08-22 23:09:20.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/sql_class.cc	2006-10-01 11:58:12.000000000 -0700
@@ -1580,6 +1580,35 @@
 }
 
 /*
+  Query functions for query stack
+*/
+
+Query::Query()
+{
+  query= NULL;
+  query_length= 0;
+}
+
+Query::Query(char *in_query, uint32 in_query_length)
+{
+  query= NULL;
+  query_length= 0;
+  set(in_query, in_query_length);
+}
+
+void Query::set(char *in_query, uint32 in_query_length)
+{
+  query= in_query;
+  query_length= in_query_length;
+}
+
+void Query::get(char **out_query, uint32 *out_query_length)
+{
+  *out_query= query;
+  *out_query_length= query_length;
+}
+  
+/*
   Statement functions 
 */
 
diff -Nur -x bdb mysql-5.0.25-nightly-20060823.orig/sql/sql_class.h mysql-5.0.25-nightly-20060823.caller/sql/sql_class.h
--- mysql-5.0.25-nightly-20060823.orig/sql/sql_class.h	2006-08-22 23:09:20.000000000 -0700
+++ mysql-5.0.25-nightly-20060823.caller/sql/sql_class.h	2006-10-01 12:20:07.000000000 -0700
@@ -748,6 +748,19 @@
 
 class Server_side_cursor;
 
+class Query: public ilink
+{
+public:
+  char *query;
+  uint32 query_length;
+
+  Query();
+  Query(char *in_query, uint32 in_query_length);
+
+  void set(char *in_query, uint32 in_query_length);
+  void get(char **out_query, uint32 *out_query_length);
+};
+
 /*
   State of a single command executed against this connection.
   One connection can contain a lot of simultaneously running statements,
@@ -811,6 +824,8 @@
   uint32 query_length;                          // current query length
   Server_side_cursor *cursor;
 
+  List<Query> query_stack;
+
 public:
 
   /* This constructor is called for backup statements */