Backport of revno 2630.28.10, 2630.28.31, 2630.28.26, 2630.33.1,

2630.39.1, 2630.28.29, 2630.34.3, 2630.34.2, 2630.34.1, 2630.29.29,
2630.29.28, 2630.31.1, 2630.28.13, 2630.28.10, 2617.23.14 and
some other minor revisions.

This patch implements: 

WL#4264 "Backup: Stabilize Service Interface" -- all the
server prerequisites except si_objects.{h,cc} themselves (they can
be just copied over, when needed).

WL#4435: Support OUT-parameters in prepared statements.

(and all issues in the initial patches for these two
tasks, that were discovered in pushbuild and during testing).

Bug#39519: mysql_stmt_close() should flush all data
associated with the statement.

After execution of a prepared statement, send OUT parameters of the invoked
stored procedure, if any, to the client.

When using the binary protocol, send the parameters in an additional result
set over the wire.  When using the text protocol, assign out parameters to
the user variables from the CALL(@var1, @var2, ...) specification.

The following refactoring has been made:
  - Protocol::send_fields() was renamed to Protocol::send_result_set_metadata();
  - A new Protocol::send_result_set_row() was introduced to incapsulate
    common functionality for sending row data.
  - Signature of Protocol::prepare_for_send() was changed: this operation
    does not need a list of items, the number of items is fully sufficient.

The following backward incompatible changes have been made:
  - CLIENT_MULTI_RESULTS is now enabled by default in the client;
  - CLIENT_PS_MULTI_RESUTLS is now enabled by default in the client.

1 files changed, 90 insertions, 37 deletions

diff --git a/libmysql/libmysql.c b/libmysql/libmysql.c
index f922c98de3a..56a2e492226 100644
--- a/libmysql/libmysql.c
+++ b/libmysql/libmysql.c
@@ -1722,6 +1722,8 @@ static void alloc_stmt_fields(MYSQL_STMT *stmt)
   MEM_ROOT *alloc= &stmt->mem_root;
   MYSQL *mysql= stmt->mysql;
 
+  DBUG_ASSERT(mysql->field_count);
+
   stmt->field_count= mysql->field_count;
 
   /*
@@ -1743,18 +1745,21 @@ static void alloc_stmt_fields(MYSQL_STMT *stmt)
 	 field= stmt->fields;
        field && fields < end; fields++, field++)
   {
-    field->db       = strdup_root(alloc,fields->db);
-    field->table    = strdup_root(alloc,fields->table);
-    field->org_table= strdup_root(alloc,fields->org_table);
-    field->name     = strdup_root(alloc,fields->name);
-    field->org_name = strdup_root(alloc,fields->org_name);
-    field->charsetnr= fields->charsetnr;
-    field->length   = fields->length;
-    field->type     = fields->type;
-    field->flags    = fields->flags;
-    field->decimals = fields->decimals;
-    field->def      = fields->def ? strdup_root(alloc,fields->def): 0;
-    field->max_length= 0;
+    *field= *fields; /* To copy all numeric parts. */
+    field->catalog=   strmake_root(alloc, fields->catalog,
+                                   fields->catalog_length);
+    field->db=        strmake_root(alloc, fields->db, fields->db_length);
+    field->table=     strmake_root(alloc, fields->table, fields->table_length);
+    field->org_table= strmake_root(alloc, fields->org_table,
+                                   fields->org_table_length);
+    field->name=      strmake_root(alloc, fields->name, fields->name_length);
+    field->org_name=  strmake_root(alloc, fields->org_name,
+                                   fields->org_name_length);
+    field->def=       fields->def ? strmake_root(alloc, fields->def,
+                                                 fields->def_length) : 0;
+    field->def_length= field->def ? fields->def_length : 0;
+    field->extension= 0; /* Avoid dangling links. */
+    field->max_length= 0; /* max_length is set in mysql_stmt_store_result() */
   }
 }
 
@@ -2481,6 +2486,33 @@ static void reinit_result_set_metadata(MYSQL_STMT *stmt)
 }
 
 
+static void prepare_to_fetch_result(MYSQL_STMT *stmt)
+{
+  if (stmt->server_status & SERVER_STATUS_CURSOR_EXISTS)
+  {
+    stmt->mysql->status= MYSQL_STATUS_READY;
+    stmt->read_row_func= stmt_read_row_from_cursor;
+  }
+  else if (stmt->flags & CURSOR_TYPE_READ_ONLY)
+  {
+    /*
+      This is a single-row result set, a result set with no rows, EXPLAIN,
+      SHOW VARIABLES, or some other command which either a) bypasses the
+      cursors framework in the server and writes rows directly to the
+      network or b) is more efficient if all (few) result set rows are
+      precached on client and server's resources are freed.
+    */
+    mysql_stmt_store_result(stmt);
+  }
+  else
+  {
+    stmt->mysql->unbuffered_fetch_owner= &stmt->unbuffered_fetch_cancelled;
+    stmt->unbuffered_fetch_cancelled= FALSE;
+    stmt->read_row_func= stmt_read_row_unbuffered;
+  }
+}
+
+
 /*
   Send placeholders data to server (if there are placeholders)
   and execute prepared statement.
@@ -2548,28 +2580,7 @@ int STDCALL mysql_stmt_execute(MYSQL_STMT *stmt)
   if (mysql->field_count)
   {
     reinit_result_set_metadata(stmt);
-    if (stmt->server_status & SERVER_STATUS_CURSOR_EXISTS)
-    {
-      mysql->status= MYSQL_STATUS_READY;
-      stmt->read_row_func= stmt_read_row_from_cursor;
-    }
-    else if (stmt->flags & CURSOR_TYPE_READ_ONLY)
-    {
-      /*
-        This is a single-row result set, a result set with no rows, EXPLAIN,
-        SHOW VARIABLES, or some other command which either a) bypasses the
-        cursors framework in the server and writes rows directly to the
-        network or b) is more efficient if all (few) result set rows are
-        precached on client and server's resources are freed.
-      */
-      mysql_stmt_store_result(stmt);
-    }
-    else
-    {
-      stmt->mysql->unbuffered_fetch_owner= &stmt->unbuffered_fetch_cancelled;
-      stmt->unbuffered_fetch_cancelled= FALSE;
-      stmt->read_row_func= stmt_read_row_unbuffered;
-    }
+    prepare_to_fetch_result(stmt);
   }
   DBUG_RETURN(test(stmt->last_errno));
 }
@@ -4034,7 +4045,6 @@ static my_bool setup_one_fetch_function(MYSQL_BIND *param, MYSQL_FIELD *field)
     field->max_length= 10;                    /* 2003-11-11 */
     param->skip_result= skip_result_with_length;
     break;
-    break;
   case MYSQL_TYPE_DATETIME:
   case MYSQL_TYPE_TIMESTAMP:
     param->skip_result= skip_result_with_length;
@@ -4614,7 +4624,7 @@ static my_bool reset_stmt_handle(MYSQL_STMT *stmt, uint flags)
         if (stmt->field_count && mysql->status != MYSQL_STATUS_READY)
         {
           /* There is a result set and it belongs to this statement */
-          (*mysql->methods->flush_use_result)(mysql);
+          (*mysql->methods->flush_use_result)(mysql, FALSE);
           if (mysql->unbuffered_fetch_owner)
             *mysql->unbuffered_fetch_owner= TRUE;
           mysql->status= MYSQL_STATUS_READY;
@@ -4698,7 +4708,7 @@ my_bool STDCALL mysql_stmt_close(MYSQL_STMT *stmt)
           Flush result set of the connection. If it does not belong
           to this statement, set a warning.
         */
-        (*mysql->methods->flush_use_result)(mysql);
+        (*mysql->methods->flush_use_result)(mysql, TRUE);
         if (mysql->unbuffered_fetch_owner)
           *mysql->unbuffered_fetch_owner= TRUE;
         mysql->status= MYSQL_STATUS_READY;
@@ -4846,6 +4856,49 @@ int STDCALL mysql_next_result(MYSQL *mysql)
 }
 
 
+int STDCALL mysql_stmt_next_result(MYSQL_STMT *stmt)
+{
+  MYSQL *mysql= stmt->mysql;
+  int rc;
+  DBUG_ENTER("mysql_stmt_next_result");
+
+  if (!mysql)
+    DBUG_RETURN(1);
+
+  if (stmt->last_errno)
+    DBUG_RETURN(stmt->last_errno);
+
+  if (mysql->server_status & SERVER_MORE_RESULTS_EXISTS)
+  {
+    if (reset_stmt_handle(stmt, RESET_STORE_RESULT))
+      DBUG_RETURN(1);
+  }
+
+  rc= mysql_next_result(mysql);
+
+  if (rc)
+  {
+    set_stmt_errmsg(stmt, &mysql->net);
+    DBUG_RETURN(rc);
+  }
+
+  stmt->state= MYSQL_STMT_EXECUTE_DONE;
+  stmt->bind_result_done= FALSE;
+
+  if (mysql->field_count)
+  {
+    alloc_stmt_fields(stmt);
+    prepare_to_fetch_result(stmt);
+  }
+  else
+  {
+    stmt->field_count= mysql->field_count;
+  }
+
+  DBUG_RETURN(0);
+}
+
+
 MYSQL_RES * STDCALL mysql_use_result(MYSQL *mysql)
 {
   return (*mysql->methods->use_result)(mysql);