MDEV-11952 Oracle-style packages: stage#5

- CREATE PACKAGE [BODY] statements are now
  entirely written to mysql.proc with type='PACKAGE' and type='PACKAGE BODY'.
- CREATE PACKAGE BODY now supports IF NOT EXISTS
- DROP PACKAGE BODY now supports IF EXISTS
- CREATE OR REPLACE PACKAGE [BODY] is now supported
- CREATE PACKAGE [BODY] now support the DEFINER clause:

    CREATE DEFINER user@host PACKAGE pkg ... END;
    CREATE DEFINER user@host PACKAGE BODY pkg ... END;

- CREATE PACKAGE [BODY] now supports SQL SECURITY and COMMENT clauses, e.g.:

    CREATE PACKAGE p1 SQL SECURITY INVOKER COMMENT "comment" AS ... END;

- Package routines are now created from the package CREATE PACKAGE BODY
  statement and don't produce individual records in mysql.proc.

- CREATE PACKAGE BODY now supports package-wide variables.
  Package variables can be read and set inside package routines.
  Package variables are stored in a separate sp_rcontext,
  which is cached in THD on the first packate routine call.

- CREATE PACKAGE BODY now supports the initialization section.

- All public routines (i.e. declared in CREATE PACKAGE)
  must have implementations in CREATE PACKAGE BODY

- Only public package routines are available outside of the package

- {CREATE|DROP} PACKAGE [BODY] now respects CREATE ROUTINE and ALTER ROUTINE
  privileges

- "GRANT EXECUTE ON PACKAGE BODY pkg" is now supported

- SHOW CREATE PACKAGE [BODY] is now supported

- SHOW PACKAGE [BODY] STATUS is now supported

- CREATE and DROP for PACKAGE [BODY] now works for non-current databases

- mysqldump now supports packages

- "SHOW {PROCEDURE|FUNCTION) CODE pkg.routine" now works for package routines

- "SHOW PACKAGE BODY CODE pkg" now works (the package initialization section)

- A new package body level MDL was added

- Recursive calls for package procedures are now possible

- Routine forward declarations in CREATE PACKATE BODY are now supported.

- Package body variables now work as SP OUT parameters

- Package body variables now work as SELECT INTO targets

- Package body variables now support ROW, %ROWTYPE, %TYPE

sql/sql_show.cc

@@ -2546,6 +2546,17 @@ static const LEX_CSTRING *view_algorithm(TABLE_LIST *table)
   }
 }
 
+
+static bool append_at_host(THD *thd, String *buffer, const LEX_CSTRING *host)
+{
+  if (!host->str || !host->str[0])
+    return false;
+  return
+    buffer->append('@') ||
+    append_identifier(thd, buffer, host);
+}
+
+
 /*
   Append DEFINER clause to the given buffer.
 
@@ -2557,17 +2568,14 @@ static const LEX_CSTRING *view_algorithm(TABLE_LIST *table)
     definer_host  [in] host name part of definer
 */
 
-void append_definer(THD *thd, String *buffer, const LEX_CSTRING *definer_user,
+bool append_definer(THD *thd, String *buffer, const LEX_CSTRING *definer_user,
                     const LEX_CSTRING *definer_host)
 {
-  buffer->append(STRING_WITH_LEN("DEFINER="));
-  append_identifier(thd, buffer, definer_user);
-  if (definer_host->str && definer_host->str[0])
-  {
-    buffer->append('@');
-    append_identifier(thd, buffer, definer_host);
-  }
-  buffer->append(' ');
+  return
+    buffer->append(STRING_WITH_LEN("DEFINER=")) ||
+    append_identifier(thd, buffer, definer_user) ||
+    append_at_host(thd, buffer, definer_host) ||
+    buffer->append(' ');
 }
 
 
@@ -9028,7 +9036,7 @@ ST_FIELD_INFO proc_fields_info[]=
    SKIP_OPEN_TABLE},
   {"ROUTINE_NAME", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0, 0, "Name",
    SKIP_OPEN_TABLE},
-  {"ROUTINE_TYPE", 9, MYSQL_TYPE_STRING, 0, 0, "Type", SKIP_OPEN_TABLE},
+  {"ROUTINE_TYPE", 13, MYSQL_TYPE_STRING, 0, 0, "Type", SKIP_OPEN_TABLE},
   {"DATA_TYPE", NAME_CHAR_LEN, MYSQL_TYPE_STRING, 0, 0, 0, SKIP_OPEN_TABLE},
   {"CHARACTER_MAXIMUM_LENGTH", 21 , MYSQL_TYPE_LONG, 0, 1, 0, SKIP_OPEN_TABLE},
   {"CHARACTER_OCTET_LENGTH", 21 , MYSQL_TYPE_LONG, 0, 1, 0, SKIP_OPEN_TABLE},