MDEV-5273 Prepared statement doesn't return metadata after prepare.

        SHOW CREATE PROCEDURE/FUNCTION fixed.

Author: Alexey Botchkov

sql/sp_head.cc

@@ -2531,6 +2531,69 @@ bool check_show_routine_access(THD *thd, sp_head *sp, bool *full_access)
 }
 
 
+/**
+  Collect metadata for SHOW CREATE statement for stored routines.
+
+  @param thd  Thread context.
+  @param type         Stored routine type
+  @param type         Stored routine type
+                      (TYPE_ENUM_PROCEDURE or TYPE_ENUM_FUNCTION)
+
+  @return Error status.
+    @retval FALSE on success
+    @retval TRUE on error
+*/
+
+void
+sp_head::show_create_routine_get_fields(THD *thd, int type, List<Item> *fields)
+{
+  const char *col1_caption= type == TYPE_ENUM_PROCEDURE ?
+                            "Procedure" : "Function";
+
+  const char *col3_caption= type == TYPE_ENUM_PROCEDURE ?
+                            "Create Procedure" : "Create Function";
+
+  MEM_ROOT *mem_root= thd->mem_root;
+
+  /* Send header. */
+
+  fields->push_back(new (mem_root)
+                    Item_empty_string(thd, col1_caption, NAME_CHAR_LEN),
+                    mem_root);
+  fields->push_back(new (mem_root)
+                    Item_empty_string(thd, "sql_mode", 256),
+                    mem_root);
+
+  {
+    /*
+      NOTE: SQL statement field must be not less than 1024 in order not to
+      confuse old clients.
+    */
+
+    Item_empty_string *stmt_fld=
+      new (mem_root) Item_empty_string(thd, col3_caption, 1024);
+    stmt_fld->maybe_null= TRUE;
+
+    fields->push_back(stmt_fld, mem_root);
+  }
+
+  fields->push_back(new (mem_root)
+                   Item_empty_string(thd, "character_set_client",
+                                     MY_CS_NAME_SIZE),
+                   mem_root);
+
+  fields->push_back(new (mem_root)
+                   Item_empty_string(thd, "collation_connection",
+                                     MY_CS_NAME_SIZE),
+                   mem_root);
+
+  fields->push_back(new (mem_root)
+                   Item_empty_string(thd, "Database Collation",
+                                     MY_CS_NAME_SIZE),
+                   mem_root);
+}
+
+
 /**
   Implement SHOW CREATE statement for stored routines.
 

sql/sp_head.h

@@ -340,6 +340,9 @@ class sp_head :private Query_arena
   bool
   execute_procedure(THD *thd, List<Item> *args);
 
+  static void
+  show_create_routine_get_fields(THD *thd, int type, List<Item> *fields);
+
   bool
   show_create_routine(THD *thd, int type);
 

sql/sql_prepare.cc

@@ -1963,6 +1963,29 @@ static bool mysql_test_show_binlogs(Prepared_statement *stmt)
 }
 
 
+/**
+  Validate and prepare for execution SHOW CREATE PROC/FUNC statement.
+
+  @param stmt               prepared statement
+
+  @retval
+    FALSE             success
+  @retval
+    TRUE              error, error message is set in THD
+*/
+
+static bool mysql_test_show_create_routine(Prepared_statement *stmt, int type)
+{
+  DBUG_ENTER("mysql_test_show_binlogs");
+  THD *thd= stmt->thd;
+  List<Item> fields;
+
+  sp_head::show_create_routine_get_fields(thd, type, &fields);
+    
+  DBUG_RETURN(send_stmt_metadata(thd, stmt, &fields));
+}
+
+
 /**
   @brief Validate and prepare for execution CREATE VIEW statement
 
@@ -2338,6 +2361,20 @@ static bool check_prepared_statement(Prepared_statement *stmt)
       DBUG_RETURN(FALSE);
     }
     break;
+  case SQLCOM_SHOW_CREATE_PROC:
+    if (!(res= mysql_test_show_create_routine(stmt, TYPE_ENUM_PROCEDURE)))
+    {
+      /* Statement and field info has already been sent */
+      DBUG_RETURN(FALSE);
+    }
+    break;
+  case SQLCOM_SHOW_CREATE_FUNC:
+    if (!(res= mysql_test_show_create_routine(stmt, TYPE_ENUM_FUNCTION)))
+    {
+      /* Statement and field info has already been sent */
+      DBUG_RETURN(FALSE);
+    }
+    break;
   case SQLCOM_CREATE_VIEW:
     if (lex->create_view_mode == VIEW_ALTER)
     {

tests/mysql_client_test.c

@@ -457,6 +457,20 @@ static void test_prepare_simple()
   DIE_UNLESS(mysql_stmt_field_count(stmt) == 4);
   mysql_stmt_close(stmt);
 
+  /* show create procedure */
+  strmov(query, "SHOW CREATE PROCEDURE e1;");
+  stmt= mysql_simple_prepare(mysql, query);
+  check_stmt(stmt);
+  DIE_UNLESS(mysql_stmt_field_count(stmt) == 6);
+  mysql_stmt_close(stmt);
+
+  /* show create function */
+  strmov(query, "SHOW CREATE FUNCTION e1;");
+  stmt= mysql_simple_prepare(mysql, query);
+  check_stmt(stmt);
+  DIE_UNLESS(mysql_stmt_field_count(stmt) == 6);
+  mysql_stmt_close(stmt);
+
   /* now fetch the results ..*/
   rc= mysql_commit(mysql);
   myquery(rc);