MDEV-12011 sql_mode=ORACLE: cursor%ROWTYPE in variable declarations

Implementing cursor%ROWTYPE variables, according to the task description.

This patch includes a refactoring in how sp_instr_cpush and sp_instr_copen
work. This is needed to implement MDEV-10598 later easier, to allow variable
declarations go after cursor declarations (which is currently not allowed).

Before this patch, sp_instr_cpush worked as a Query_arena associated with
the cursor. sp_instr_copen::execute() switched to the sp_instr_cpush's
Query_arena when executing the cursor SELECT statement.

Now the Query_arena associated with the cursor is stored inside an instance
of a new class sp_lex_cursor (a LEX descendand) that contains the cursor SELECT
statement.

This simplifies the implementation, because:
- It's easier to follow the code when everything related to execution
  of the cursor SELECT statement is stored inside the same sp_lex_cursor
  object (rather than distributed between LEX and sp_instr_cpush).
- It's easier to link an sp_instr_cursor_copy_struct to
  sp_lex_cursor rather than to sp_instr_cpush.
- Also, it allows to perform sp_instr_cursor_copy_struct::exec_core()
  without having a pointer to sp_instr_cpush, using a pointer to sp_lex_cursor
  instead. This will be important for MDEV-10598, because sp_instr_cpush will
  happen *after* sp_instr_cursor_copy_struct.

After MDEV-10598 is done, this declaration:

DECLARE
  CURSOR cur IS SELECT * FROM t1;
  rec cur%ROWTYPE;
BEGIN
  OPEN cur;
  FETCH cur INTO rec;
  CLOSE cur;
END;

will generate about this code:

+-----+--------------------------+
| Pos | Instruction              |
+-----+--------------------------+
|   0 | cursor_copy_struct rec@0 | Points to sp_cursor_lex through m_lex_keeper
|   1 | set rec@0 NULL           |
|   2 | cpush cur@0              | Points to sp_cursor_lex through m_lex_keeper
|   3 | copen cur@0              | Points to sp_cursor_lex through m_cursor
|   4 | cfetch cur@0 rec@0       |
|   5 | cclose cur@0             |
|   6 | cpop 1                   |
+-----+--------------------------+

Notice, "cursor_copy_struct" and "set" will go before "cpush".
Instructions at positions 0, 2, 3 point to the same sp_cursor_lex instance.

16 files changed, 351 insertions, 83 deletions

diff --git a/sql/field.h b/sql/field.h
index e110e1f8146..3b96dd546cb 100644
--- a/sql/field.h
+++ b/sql/field.h
@@ -3987,6 +3987,16 @@ public:
 };
 
 
+class Cursor_rowtype: public Sql_alloc
+{
+public:
+  uint m_cursor;
+  Cursor_rowtype(uint cursor)
+   :m_cursor(cursor)
+  { }
+};
+
+
 /**
   This class is used during a stored routine or a trigger execution,
   at sp_rcontext::create() time.
@@ -4010,20 +4020,25 @@ class Spvar_definition: public Column_definition
 {
   class Qualified_column_ident *m_column_type_ref; // for %TYPE
   class Table_ident *m_table_rowtype_ref;          // for table%ROWTYPE
+  class Cursor_rowtype *m_cursor_rowtype_ref;      // for cursor%ROWTYPE
   Row_definition_list *m_row_field_definitions;    // for ROW
 public:
   Spvar_definition()
    :m_column_type_ref(NULL),
     m_table_rowtype_ref(NULL),
-    m_row_field_definitions(NULL) { }
+    m_cursor_rowtype_ref(NULL),
+    m_row_field_definitions(NULL)
+  { }
   Spvar_definition(THD *thd, Field *field)
    :Column_definition(thd, field, NULL),
     m_column_type_ref(NULL),
     m_table_rowtype_ref(NULL),
+    m_cursor_rowtype_ref(NULL),
     m_row_field_definitions(NULL)
   { }
   bool is_column_type_ref() const { return m_column_type_ref != 0; }
   bool is_table_rowtype_ref() const { return m_table_rowtype_ref != 0; }
+  bool is_cursor_rowtype_ref() const { return m_cursor_rowtype_ref != NULL; }
   class Qualified_column_ident *column_type_ref() const
   {
     return m_column_type_ref;
@@ -4041,6 +4056,14 @@ public:
   {
     m_table_rowtype_ref= ref;
   }
+  class Cursor_rowtype *cursor_rowtype_ref() const
+  {
+    return m_cursor_rowtype_ref;
+  }
+  void set_cursor_rowtype_ref(class Cursor_rowtype *ref)
+  {
+    m_cursor_rowtype_ref= ref;
+  }
 
   /*
     Find a ROW field by name.
diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index a40ad52676c..2b5b1db5ddf 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -3152,6 +3152,26 @@ sp_lex_keeper::reset_lex_and_exec_core(THD *thd, uint *nextp,
 }
 
 
+int sp_lex_keeper::cursor_reset_lex_and_exec_core(THD *thd, uint *nextp,
+                                                  bool open_tables,
+                                                  sp_instr *instr)
+{
+  Query_arena *old_arena= thd->stmt_arena;
+  /*
+    Get the Query_arena from the cursor statement LEX, which contains
+    the free_list of the query, so new items (if any) are stored in
+    the right free_list, and we can cleanup after each cursor operation,
+    e.g. open or cursor_copy_struct (for cursor%ROWTYPE variables).
+  */
+  thd->stmt_arena= m_lex->query_arena();
+  int res= reset_lex_and_exec_core(thd, nextp, open_tables, instr);
+  if (thd->stmt_arena->free_list)
+    cleanup_items(thd->stmt_arena->free_list);
+  thd->stmt_arena= old_arena;
+  return res;
+}
+
+
 /*
   sp_instr class functions
 */
@@ -3455,7 +3475,8 @@ sp_instr_set_row_field_by_name::print(String *str)
   int rsrv= SP_INSTR_UINT_MAXLEN + 6 + 6 + 3 + 2;
   sp_variable *var= m_ctx->find_variable(m_offset);
   DBUG_ASSERT(var);
-  DBUG_ASSERT(var->field_def.is_table_rowtype_ref());
+  DBUG_ASSERT(var->field_def.is_table_rowtype_ref() ||
+              var->field_def.is_cursor_rowtype_ref());
 
   rsrv+= var->name.length + 2 * m_field_name.length;
   if (str->reserve(rsrv))
@@ -3915,7 +3936,7 @@ sp_instr_cpush::execute(THD *thd, uint *nextp)
 {
   DBUG_ENTER("sp_instr_cpush::execute");
 
-  int ret= thd->spcont->push_cursor(thd, &m_lex_keeper, this);
+  int ret= thd->spcont->push_cursor(thd, &m_lex_keeper);
 
   *nextp= m_ip+1;
 
@@ -3995,19 +4016,7 @@ sp_instr_copen::execute(THD *thd, uint *nextp)
   else
   {
     sp_lex_keeper *lex_keeper= c->get_lex_keeper();
-    Query_arena *old_arena= thd->stmt_arena;
-
-    /*
-      Get the Query_arena from the cpush instruction, which contains
-      the free_list of the query, so new items (if any) are stored in
-      the right free_list, and we can cleanup after each open.
-    */
-    thd->stmt_arena= c->get_instr();
-    res= lex_keeper->reset_lex_and_exec_core(thd, nextp, FALSE, this);
-    /* Cleanup the query's items */
-    if (thd->stmt_arena->free_list)
-      cleanup_items(thd->stmt_arena->free_list);
-    thd->stmt_arena= old_arena;
+    res= lex_keeper->cursor_reset_lex_and_exec_core(thd, nextp, FALSE, this);
     /* TODO: Assert here that we either have an error or a cursor */
   }
   DBUG_RETURN(res);
@@ -4140,6 +4149,72 @@ sp_instr_cfetch::print(String *str)
 
 
 /*
+  sp_instr_cursor_copy_struct class functions
+*/
+
+int
+sp_instr_cursor_copy_struct::exec_core(THD *thd, uint *nextp)
+{
+  DBUG_ENTER("sp_instr_cusrot_copy_struct::exec_core");
+  int ret= 0;
+  Item_field_row *row= (Item_field_row*) thd->spcont->get_item(m_var);
+  DBUG_ASSERT(row->type_handler() == &type_handler_row);
+
+  /*
+    Copy structure only once. If the cursor%ROWTYPE variable is declared
+    inside a LOOP block, it gets its structure on the first loop interation
+    and remembers the structure for all consequent loop iterations.
+    It we recreated the structure on every iteration, we would get
+    potential memory leaks, and it would be less efficient.
+  */
+  if (!row->arguments())
+  {
+    sp_cursor tmp(thd, &m_lex_keeper);
+    if (!(ret= tmp.open_view_structure_only(thd)))
+    {
+      Row_definition_list defs;
+      if (!(ret= tmp.export_structure(thd, &defs)))
+      {
+        /*
+          Create row elements on the caller arena.
+          It's the same arena that was used during sp_rcontext::create().
+          This puts cursor%ROWTYPE elements on the same mem_root
+          where explicit ROW elements and table%ROWTYPE reside.
+        */
+        Query_arena current_arena;
+        thd->set_n_backup_active_arena(thd->spcont->callers_arena, &current_arena);
+        row->row_create_items(thd, &defs);
+        thd->restore_active_arena(thd->spcont->callers_arena, &current_arena);
+      }
+      tmp.close(thd);
+    }
+  }
+  *nextp= m_ip + 1;
+  DBUG_RETURN(ret);
+}
+
+
+int
+sp_instr_cursor_copy_struct::execute(THD *thd, uint *nextp)
+{
+  DBUG_ENTER("sp_instr_cursor_copy_struct::execute");
+  int ret= m_lex_keeper.cursor_reset_lex_and_exec_core(thd, nextp, FALSE, this);
+  DBUG_RETURN(ret);
+}
+
+
+void
+sp_instr_cursor_copy_struct::print(String *str)
+{
+  sp_variable *var= m_ctx->find_variable(m_var);
+  str->append(STRING_WITH_LEN("cursor_copy_struct "));
+  str->append(var->name.str, var->name.length);
+  str->append('@');
+  str->append_ulonglong(m_var);
+}
+
+
+/*
   sp_instr_error class functions
 */
 
diff --git a/sql/sp_head.h b/sql/sp_head.h
index 92f17884285..37ef4b6825f 100644
--- a/sql/sp_head.h
+++ b/sql/sp_head.h
@@ -341,6 +341,8 @@ public:
   bool
   show_create_routine(THD *thd, int type);
 
+  MEM_ROOT *get_main_mem_root() { return &main_mem_root; }
+
   int
   add_instr(sp_instr *instr);
 
@@ -767,6 +769,42 @@ private:
 }; // class sp_head : public Sql_alloc
 
 
+class sp_lex_cursor: public sp_lex_local, public Query_arena
+{
+public:
+  sp_lex_cursor(THD *thd, const LEX *oldlex, MEM_ROOT *mem_root_arg)
+   :sp_lex_local(thd, oldlex),
+    Query_arena(mem_root_arg, STMT_INITIALIZED_FOR_SP)
+  { }
+  sp_lex_cursor(THD *thd, const LEX *oldlex)
+   :sp_lex_local(thd, oldlex),
+    Query_arena(thd->lex->sphead->get_main_mem_root(), STMT_INITIALIZED_FOR_SP)
+  { }
+  ~sp_lex_cursor() { free_items(); }
+  void cleanup_stmt() { }
+  Query_arena *query_arena() { return this; }
+  bool validate()
+  {
+    DBUG_ASSERT(sql_command == SQLCOM_SELECT);
+    if (result)
+    {
+      my_error(ER_SP_BAD_CURSOR_SELECT, MYF(0));
+      return true;
+    }
+    return false;
+  }
+  bool stmt_finalize(THD *thd)
+  {
+    if (validate())
+      return true;
+    sp_lex_in_use= true;
+    free_list= thd->free_list;
+    thd->free_list= NULL;
+    return false;
+  }
+};
+
+
 //
 // "Instructions"...
 //
@@ -924,6 +962,9 @@ public:
   int reset_lex_and_exec_core(THD *thd, uint *nextp, bool open_tables,
                               sp_instr* instr);
 
+  int cursor_reset_lex_and_exec_core(THD *thd, uint *nextp, bool open_tables,
+                                     sp_instr *instr);
+
   inline uint sql_command() const
   {
     return (uint)m_lex->sql_command;
@@ -1550,6 +1591,30 @@ private:
 }; // class sp_instr_copen : public sp_instr_stmt
 
 
+/**
+  Initialize the structure of a cursor%ROWTYPE variable
+  from the LEX containing the cursor SELECT statement.
+*/
+class sp_instr_cursor_copy_struct: public sp_instr
+{
+  /**< Prevent use of these */
+  sp_instr_cursor_copy_struct(const sp_instr_cursor_copy_struct &);
+  void operator=(sp_instr_cursor_copy_struct &);
+  sp_lex_keeper m_lex_keeper;
+  uint m_var;
+public:
+  sp_instr_cursor_copy_struct(uint ip, sp_pcontext *ctx,
+                              sp_lex_cursor *lex, uint voffs)
+    : sp_instr(ip, ctx), m_lex_keeper(lex, FALSE), m_var(voffs)
+  {}
+  virtual ~sp_instr_cursor_copy_struct()
+  {}
+  virtual int execute(THD *thd, uint *nextp);
+  virtual int exec_core(THD *thd, uint *nextp);
+  virtual void print(String *str);
+};
+
+
 class sp_instr_cclose : public sp_instr
 {
   sp_instr_cclose(const sp_instr_cclose &); /**< Prevent use of these */
diff --git a/sql/sp_pcontext.cc b/sql/sp_pcontext.cc
index 332f43db846..3a3ad0713b5 100644
--- a/sql/sp_pcontext.cc
+++ b/sql/sp_pcontext.cc
@@ -553,12 +553,13 @@ sp_pcontext::find_handler(const Sql_condition_identity &value) const
 }
 
 
-bool sp_pcontext::add_cursor(const LEX_STRING name, sp_pcontext *param_ctx)
+bool sp_pcontext::add_cursor(const LEX_STRING name, sp_pcontext *param_ctx,
+                             sp_lex_cursor *lex)
 {
   if (m_cursors.elements() == m_max_cursor_index)
     ++m_max_cursor_index;
 
-  return m_cursors.append(sp_pcursor(name, param_ctx));
+  return m_cursors.append(sp_pcursor(name, param_ctx, lex));
 }
 
 
diff --git a/sql/sp_pcontext.h b/sql/sp_pcontext.h
index 85d0afa8feb..6d8f5e1baf8 100644
--- a/sql/sp_pcontext.h
+++ b/sql/sp_pcontext.h
@@ -288,11 +288,14 @@ public:
 class sp_pcursor: public LEX_STRING
 {
   class sp_pcontext *m_param_context; // Formal parameters
+  class sp_lex_cursor *m_lex;         // The cursor statement LEX
 public:
-  sp_pcursor(const LEX_STRING &name, class sp_pcontext *param_ctx)
-   :LEX_STRING(name), m_param_context(param_ctx)
+  sp_pcursor(const LEX_STRING &name, class sp_pcontext *param_ctx,
+             class sp_lex_cursor *lex)
+   :LEX_STRING(name), m_param_context(param_ctx), m_lex(lex)
   { }
   class sp_pcontext *param_context() const { return m_param_context; }
+  class sp_lex_cursor *lex() const { return m_lex; }
 };
 
 
@@ -633,7 +636,8 @@ public:
   // Cursors.
   /////////////////////////////////////////////////////////////////////////
 
-  bool add_cursor(const LEX_STRING name, sp_pcontext *param_ctx);
+  bool add_cursor(const LEX_STRING name, sp_pcontext *param_ctx,
+                  class sp_lex_cursor *lex);
 
   /// See comment for find_variable() above.
   const sp_pcursor *find_cursor(const LEX_STRING name,
diff --git a/sql/sp_rcontext.cc b/sql/sp_rcontext.cc
index b631ad71e49..d60d7f5118f 100644
--- a/sql/sp_rcontext.cc
+++ b/sql/sp_rcontext.cc
@@ -286,6 +286,13 @@ bool sp_rcontext::init_var_items(THD *thd,
           item->row_create_items(thd, &defs))
         return true;
     }
+    else if (def->is_cursor_rowtype_ref())
+    {
+      Row_definition_list defs;
+      Item_field_row *item= new (thd->mem_root) Item_field_row(thd, field);
+      if (!(m_var_items[idx]= item))
+        return true;
+    }
     else if (def->is_row())
     {
       Item_field_row *item= new (thd->mem_root) Item_field_row(thd, field);
@@ -341,14 +348,13 @@ bool sp_rcontext::set_return_value(THD *thd, Item **return_value_item)
 }
 
 
-bool sp_rcontext::push_cursor(THD *thd, sp_lex_keeper *lex_keeper,
-                              sp_instr_cpush *i)
+bool sp_rcontext::push_cursor(THD *thd, sp_lex_keeper *lex_keeper)
 {
   /*
     We should create cursors in the callers arena, as
     it could be (and usually is) used in several instructions.
   */
-  sp_cursor *c= new (callers_arena->mem_root) sp_cursor(thd, lex_keeper, i);
+  sp_cursor *c= new (callers_arena->mem_root) sp_cursor(thd, lex_keeper);
 
   if (c == NULL)
     return true;
@@ -687,11 +693,10 @@ bool sp_rcontext::set_case_expr(THD *thd, int case_expr_id,
 ///////////////////////////////////////////////////////////////////////////
 
 
-sp_cursor::sp_cursor(THD *thd_arg, sp_lex_keeper *lex_keeper, sp_instr_cpush *i):
+sp_cursor::sp_cursor(THD *thd_arg, sp_lex_keeper *lex_keeper):
    result(thd_arg),
    m_lex_keeper(lex_keeper),
    server_side_cursor(NULL),
-   m_i(i),
    m_fetch_count(0),
    m_row_count(0),
    m_found(false)
@@ -731,6 +736,21 @@ int sp_cursor::open(THD *thd)
 }
 
 
+int sp_cursor::open_view_structure_only(THD *thd)
+{
+  int res;
+  int thd_no_errors_save= thd->no_errors;
+  Item *limit_rows_examined= thd->lex->limit_rows_examined;
+  if (!(thd->lex->limit_rows_examined= new (thd->mem_root) Item_uint(thd, 0)))
+    return -1;
+  thd->no_errors= true; // Suppress ER_QUERY_EXCEEDED_ROWS_EXAMINED_LIMIT
+  res= open(thd);
+  thd->no_errors= thd_no_errors_save;
+  thd->lex->limit_rows_examined= limit_rows_examined;
+  return res;
+}
+
+
 int sp_cursor::close(THD *thd)
 {
   if (! server_side_cursor)
@@ -802,6 +822,11 @@ int sp_cursor::fetch(THD *thd, List<sp_variable> *vars)
 }
 
 
+bool sp_cursor::export_structure(THD *thd, Row_definition_list *list)
+{
+  return server_side_cursor->export_structure(thd, list);
+}
+
 ///////////////////////////////////////////////////////////////////////////
 // sp_cursor::Select_fetch_into_spvars implementation.
 ///////////////////////////////////////////////////////////////////////////
diff --git a/sql/sp_rcontext.h b/sql/sp_rcontext.h
index 1c47b1caff0..98464518787 100644
--- a/sql/sp_rcontext.h
+++ b/sql/sp_rcontext.h
@@ -272,7 +272,7 @@ public:
   /// @return error flag.
   /// @retval false on success.
   /// @retval true on error.
-  bool push_cursor(THD *thd, sp_lex_keeper *lex_keeper, sp_instr_cpush *i);
+  bool push_cursor(THD *thd, sp_lex_keeper *lex_keeper);
 
   /// Pop and delete given number of sp_cursor instance from the cursor stack.
   ///
@@ -434,7 +434,7 @@ private:
 };
 
 public:
-  sp_cursor(THD *thd_arg, sp_lex_keeper *lex_keeper, sp_instr_cpush *i);
+  sp_cursor(THD *thd_arg, sp_lex_keeper *lex_keeper);
 
   virtual ~sp_cursor()
   { destroy(); }
@@ -443,6 +443,8 @@ public:
 
   int open(THD *thd);
 
+  int open_view_structure_only(THD *thd);
+
   int close(THD *thd);
 
   my_bool is_open()
@@ -459,14 +461,12 @@ public:
 
   int fetch(THD *, List<sp_variable> *vars);
 
-  sp_instr_cpush *get_instr()
-  { return m_i; }
+  bool export_structure(THD *thd, Row_definition_list *list);
 
 private:
   Select_fetch_into_spvars result;
   sp_lex_keeper *m_lex_keeper;
   Server_side_cursor *server_side_cursor;
-  sp_instr_cpush *m_i;     // My push instruction
   ulonglong m_fetch_count; // Number of FETCH commands since last OPEN
   ulonglong m_row_count;   // Number of successful FETCH since last OPEN
   bool m_found;            // If last FETCH fetched a row
diff --git a/sql/sql_cursor.cc b/sql/sql_cursor.cc
index 60d80387a10..40eb7046108 100644
--- a/sql/sql_cursor.cc
+++ b/sql/sql_cursor.cc
@@ -53,6 +53,10 @@ public:
   virtual int open(JOIN *join __attribute__((unused)));
   virtual void fetch(ulong num_rows);
   virtual void close();
+  bool export_structure(THD *thd, Row_definition_list *defs)
+  {
+    return table->export_structure(thd, defs);
+  }
   virtual ~Materialized_cursor();
 
   void on_table_fill_finished();
diff --git a/sql/sql_cursor.h b/sql/sql_cursor.h
index bff47d654b3..6fa72a2005d 100644
--- a/sql/sql_cursor.h
+++ b/sql/sql_cursor.h
@@ -54,6 +54,11 @@ public:
   virtual int open(JOIN *top_level_join)= 0;
   virtual void fetch(ulong num_rows)= 0;
   virtual void close()= 0;
+  virtual bool export_structure(THD *thd, Row_definition_list *defs)
+  {
+    DBUG_ASSERT(0);
+    return true;
+  }
   virtual ~Server_side_cursor();
 
   static void operator delete(void *ptr, size_t size);
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index 8f258f50902..ca35535973e 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -5297,6 +5297,9 @@ LEX::sp_variable_declarations_rowtype_finalize(THD *thd, int nvars,
                                                Qualified_column_ident *ref,
                                                Item *def)
 {
+  uint coffp;
+  const sp_pcursor *pcursor= ref->table.str && ref->db.str ? NULL :
+                             spcont->find_cursor(ref->m_column, &coffp, false);
   uint num_vars= spcont->context_var_count();
 
   if (!def && !(def= new (thd->mem_root) Item_null(thd)))
@@ -5307,24 +5310,41 @@ LEX::sp_variable_declarations_rowtype_finalize(THD *thd, int nvars,
     bool last= i == num_vars - 1;
     uint var_idx= spcont->var_context2runtime(i);
     sp_variable *spvar= spcont->find_context_variable(i);
-    /*
-      When parsing a qualified identifier chain, the parser does not know yet
-      if it's going to be a qualified column name (for %TYPE),
-      or a qualified table name (for %ROWTYPE). So it collects the chain
-      into Qualified_column_ident.
-      Now we know that it was actually a qualified table name (%ROWTYPE).
-      Create a new Table_ident from Qualified_column_ident,
-      shifting fields as follows:
-      - ref->m_column becomes table_ref->table
-      - ref->table    becomes table_ref->db
-    */
-    Table_ident *table_ref;
-    if (!(table_ref= new (thd->mem_root) Table_ident(thd,
-                                                     ref->table,
-                                                     ref->m_column,
-                                                     false)))
-      return true;
-    spvar->field_def.set_table_rowtype_ref(table_ref);
+
+    if (pcursor)
+    {
+      Cursor_rowtype *ref;
+      if (!(ref= new (thd->mem_root) Cursor_rowtype(coffp)))
+        return true;
+      spvar->field_def.set_cursor_rowtype_ref(ref);
+      sp_instr_cursor_copy_struct *instr=
+        new (thd->mem_root) sp_instr_cursor_copy_struct(sphead->instructions(),
+                                                        spcont, pcursor->lex(),
+                                                        spvar->offset);
+      if (instr == NULL || sphead->add_instr(instr))
+       return true;
+    }
+    else
+    {
+      /*
+        When parsing a qualified identifier chain, the parser does not know yet
+        if it's going to be a qualified column name (for %TYPE),
+        or a qualified table name (for %ROWTYPE). So it collects the chain
+        into Qualified_column_ident.
+        Now we know that it was actually a qualified table name (%ROWTYPE).
+        Create a new Table_ident from Qualified_column_ident,
+        shifting fields as follows:
+        - ref->m_column becomes table_ref->table
+        - ref->table    becomes table_ref->db
+      */
+      Table_ident *table_ref;
+      if (!(table_ref= new (thd->mem_root) Table_ident(thd,
+                                                       ref->table,
+                                                       ref->m_column,
+                                                       false)))
+        return true;
+      spvar->field_def.set_table_rowtype_ref(table_ref);
+    }
     spvar->field_def.field_name= spvar->name.str;
     spvar->default_value= def;
     /* The last instruction is responsible for freeing LEX. */
@@ -5485,7 +5505,8 @@ bool LEX::sp_for_loop_finalize(THD *thd, const Lex_for_loop_st &loop)
 
 /***************************************************************************/
 
-bool LEX::sp_declare_cursor(THD *thd, const LEX_STRING name, LEX *cursor_stmt,
+bool LEX::sp_declare_cursor(THD *thd, const LEX_STRING name,
+                            sp_lex_cursor *cursor_stmt,
                             sp_pcontext *param_ctx)
 {
   uint offp;
@@ -5501,7 +5522,7 @@ bool LEX::sp_declare_cursor(THD *thd, const LEX_STRING name, LEX *cursor_stmt,
                       spcont->current_cursor_count());
   return i == NULL ||
          sphead->add_instr(i) ||
-         spcont->add_cursor(name, param_ctx);
+         spcont->add_cursor(name, param_ctx, cursor_stmt);
 }
 
 
@@ -6178,7 +6199,8 @@ Item_splocal *LEX::create_item_spvar_row_field(THD *thd,
   }
 
   Item_splocal *item;
-  if (spv->field_def.is_table_rowtype_ref())
+  if (spv->field_def.is_table_rowtype_ref() ||
+      spv->field_def.is_cursor_rowtype_ref())
   {
     if (!(item= new (thd->mem_root)
                 Item_splocal_row_field_by_name(thd, a, b, spv->offset,
@@ -6406,7 +6428,8 @@ bool LEX::set_variable(const LEX_STRING &name1,
   sp_variable *spv;
   if (spcont && (spv= spcont->find_variable(name1, false)))
   {
-    if (spv->field_def.is_table_rowtype_ref())
+    if (spv->field_def.is_table_rowtype_ref() ||
+        spv->field_def.is_cursor_rowtype_ref())
       return sphead->set_local_variable_row_field_by_name(thd, spcont,
                                                           spv, name2,
                                                           item, this);
diff --git a/sql/sql_lex.h b/sql/sql_lex.h
index 8edebaf6028..3cdf05377dd 100644
--- a/sql/sql_lex.h
+++ b/sql/sql_lex.h
@@ -2936,6 +2936,12 @@ public:
     delete_dynamic(&plugins);
   }
 
+  virtual class Query_arena *query_arena()
+  {
+    DBUG_ASSERT(0);
+    return NULL;
+  }
+
   void start(THD *thd);
 
   const char *substatement_query(THD *thd) const;
@@ -3155,7 +3161,8 @@ public:
   bool sp_handler_declaration_init(THD *thd, int type);
   bool sp_handler_declaration_finalize(THD *thd, int type);
 
-  bool sp_declare_cursor(THD *thd, const LEX_STRING name, LEX *cursor_stmt,
+  bool sp_declare_cursor(THD *thd, const LEX_STRING name,
+                         class sp_lex_cursor *cursor_stmt,
                          sp_pcontext *param_ctx);
   bool sp_open_cursor(THD *thd, const LEX_STRING name,
                       List<sp_assignment_lex> *parameters);
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index d3f2a674664..5ca19e34bac 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -377,7 +377,7 @@ bool handle_select(THD *thd, LEX *lex, select_result *result,
   res|= thd->is_error();
   if (unlikely(res))
     result->abort_result_set();
-  if (thd->killed == ABORT_QUERY)
+  if (thd->killed == ABORT_QUERY && !thd->no_errors)
   {
     /*
       If LIMIT ROWS EXAMINED interrupted query execution, issue a warning,
diff --git a/sql/sql_yacc.yy b/sql/sql_yacc.yy
index 93fdff57d38..45af801272a 100644
--- a/sql/sql_yacc.yy
+++ b/sql/sql_yacc.yy
@@ -783,6 +783,7 @@ Virtual_column_info *add_virtual_expression(THD *thd, Item *expr)
   Item_param *item_param;
   Key_part_spec *key_part;
   LEX *lex;
+  class sp_lex_cursor *sp_cursor_stmt;
   LEX_STRING *lex_str_ptr;
   LEX_USER *lex_user;
   List<Condition_information_item> *cond_info_list;
@@ -1710,6 +1711,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
         expr_list opt_udf_expr_list udf_expr_list when_list
         ident_list ident_list_arg opt_expr_list
 
+%type <sp_cursor_stmt>
+        sp_cursor_stmt_lex
+        sp_cursor_stmt
+
 %type <var_type>
         option_type opt_var_type opt_var_ident_type
 
@@ -1871,7 +1876,6 @@ END_OF_INPUT
 %type <num>  sp_decl_idents sp_handler_type sp_hcond_list
 %type <spcondvalue> sp_cond sp_hcond sqlstate signal_value opt_signal_value
 %type <spblock> sp_decls sp_decl sp_decl_body
-%type <lex> sp_cursor_stmt
 %type <spname> sp_name
 %type <spvar> sp_param_name sp_param_name_and_type
 %type <spvar_mode> sp_opt_inout
@@ -3024,22 +3028,28 @@ sp_decl_body:
           }
         ;
 
+
+sp_cursor_stmt_lex:
+          {
+            DBUG_ASSERT(thd->lex->sphead);
+            if (!($$= new (thd->mem_root) sp_lex_cursor(thd, thd->lex)))
+              MYSQL_YYABORT;
+          }
+        ;
+
 sp_cursor_stmt:
+          sp_cursor_stmt_lex
           {
-            Lex->sphead->reset_lex(thd);
+            DBUG_ASSERT(thd->free_list == NULL);
+            Lex->sphead->reset_lex(thd, $1);
           }
           select
           {
-            LEX *lex= Lex;
-
-            DBUG_ASSERT(lex->sql_command == SQLCOM_SELECT);
-
-            if (lex->result)
-              my_yyabort_error((ER_SP_BAD_CURSOR_SELECT, MYF(0)));
-            lex->sp_lex_in_use= TRUE;
-            $$= lex;
-            if (lex->sphead->restore_lex(thd))
+            DBUG_ASSERT(Lex == $1);
+            if ($1->stmt_finalize(thd) ||
+                $1->sphead->restore_lex(thd))
               MYSQL_YYABORT;
+            $$= $1;
           }
         ;
 
diff --git a/sql/sql_yacc_ora.yy b/sql/sql_yacc_ora.yy
index c72fa8ca0e5..2360b735674 100644
--- a/sql/sql_yacc_ora.yy
+++ b/sql/sql_yacc_ora.yy
@@ -199,6 +199,7 @@ void ORAerror(THD *thd, const char *s)
   Key_part_spec *key_part;
   LEX *lex;
   sp_assignment_lex *assignment_lex;
+  class sp_lex_cursor *sp_cursor_stmt;
   LEX_STRING *lex_str_ptr;
   LEX_USER *lex_user;
   List<Condition_information_item> *cond_info_list;
@@ -1150,6 +1151,10 @@ bool my_yyoverflow(short **a, YYSTYPE **b, ulong *yystacksize);
         ident_list ident_list_arg opt_expr_list
         decode_when_list
 
+%type <sp_cursor_stmt>
+        sp_cursor_stmt_lex
+        sp_cursor_stmt
+
 %type <assignment_lex>
         assignment_source_lex
         assignment_source_expr
@@ -1333,7 +1338,6 @@ END_OF_INPUT
 %type <sp_instr_addr> sp_instr_addr
 %type <sp_cursor_name_and_offset> sp_cursor_name_and_offset
 %type <num> opt_exception_clause exception_handlers
-%type <lex> sp_cursor_stmt remember_lex
 %type <spname> sp_name
 %type <spvar> sp_param_name sp_param_name_and_type
 %type <for_loop> sp_for_loop_index_and_bounds
@@ -2609,22 +2613,27 @@ opt_parenthesized_cursor_formal_parameters:
         ;
 
 
+sp_cursor_stmt_lex:
+          {
+            DBUG_ASSERT(thd->lex->sphead);
+            if (!($$= new (thd->mem_root) sp_lex_cursor(thd, thd->lex)))
+              MYSQL_YYABORT;
+          }
+        ;
+
 sp_cursor_stmt:
+          sp_cursor_stmt_lex
           {
-            Lex->sphead->reset_lex(thd);
+            DBUG_ASSERT(thd->free_list == NULL);
+            Lex->sphead->reset_lex(thd, $1);
           }
           select
           {
-            LEX *lex= Lex;
-
-            DBUG_ASSERT(lex->sql_command == SQLCOM_SELECT);
-
-            if (lex->result)
-              my_yyabort_error((ER_SP_BAD_CURSOR_SELECT, MYF(0)));
-            lex->sp_lex_in_use= TRUE;
-            $$= lex;
-            if (lex->sphead->restore_lex(thd))
+            DBUG_ASSERT(Lex == $1);
+            if ($1->stmt_finalize(thd) ||
+                $1->sphead->restore_lex(thd))
               MYSQL_YYABORT;
+            $$= $1;
           }
         ;
 
@@ -3303,12 +3312,6 @@ sp_proc_stmt_goto:
         ;
 
 
-remember_lex:
-          {
-            $$= thd->lex;
-          }
-        ;
-
 assignment_source_lex:
           {
             DBUG_ASSERT(Lex->sphead);
diff --git a/sql/table.cc b/sql/table.cc
index 38cda5cc209..ee592f120d3 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -8213,3 +8213,25 @@ Field *TABLE::find_field_by_name(const char *str) const
   }
   return NULL;
 }
+
+
+bool TABLE::export_structure(THD *thd, Row_definition_list *defs)
+{
+  for (Field **src= field; *src; src++)
+  {
+    uint offs;
+    if (defs->find_row_field_by_name(src[0]->field_name, &offs))
+    {
+      my_error(ER_DUP_FIELDNAME, MYF(0), src[0]->field_name);
+      return true;
+    }
+    Spvar_definition *def= new (thd->mem_root) Spvar_definition(thd, *src);
+    if (!def)
+      return true;
+    def->flags&= (uint) ~NOT_NULL_FLAG;
+    if ((def->sp_prepare_create_field(thd, thd->mem_root)) ||
+        (defs->push_back(def, thd->mem_root)))
+      return true;
+  }
+  return false;
+}
diff --git a/sql/table.h b/sql/table.h
index 22dfeaaa596..4885196a817 100644
--- a/sql/table.h
+++ b/sql/table.h
@@ -1441,6 +1441,7 @@ public:
                                       TMP_TABLE_PARAM *tmp_table_param,
                                       bool with_cleanup);
   Field *find_field_by_name(const char *str) const;
+  bool export_structure(THD *thd, class Row_definition_list *defs);
 };