Fix BUG#1656: Have to initialize OUT parameters too, in case they're not

later set by the procedure.

mysql-test/r/sp.result

@@ -653,6 +653,17 @@ less	2
 more	17
 delete from t1;
 drop procedure bug1547;
+drop table if exists t70;
+create table t70 (s1 int,s2 int);
+insert into t70 values (1,2);
+create procedure bug1656(out p1 int, out p2 int)
+select * into p1, p1 from t70;
+call bug1656(@1, @2);
+select @1, @2;
+@1	@2
+2	NULL
+drop table t70;
+drop procedure bug1656;
 drop table if exists fac;
 create table fac (n int unsigned not null primary key, f bigint unsigned);
 create procedure ifac(n int unsigned)

mysql-test/t/sp.test

@@ -764,6 +764,23 @@ select * from t1|
 delete from t1|
 drop procedure bug1547|
 
+#
+# BUG#1656
+#
+--disable_warnings
+drop table if exists t70|
+--enable_warnings
+create table t70 (s1 int,s2 int)|
+insert into t70 values (1,2)|
+
+create procedure bug1656(out p1 int, out p2 int)
+  select * into p1, p1 from t70|
+
+call bug1656(@1, @2)|
+select @1, @2|
+drop table t70|
+drop procedure bug1656|
+
 
 #
 # Some "real" examples

sql/sp_head.cc

@@ -373,6 +373,7 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
 
   if (csize > 0 || hmax > 0 || cmax > 0)
   {
+    Item_null *nit= NULL;	// Re-use this, and only create if needed
     uint i;
     List_iterator_fast<Item> li(*args);
     Item *it;
@@ -393,7 +394,11 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
       else
       {
 	if (pvar->mode == sp_param_out)
-	  nctx->push_item(NULL); // OUT
+	{
+	  if (! nit)
+	    nit= new Item_null();
+	  nctx->push_item(nit); // OUT
+	}
 	else
 	  nctx->push_item(sp_eval_func_item(thd, it,pvar->type)); // IN or INOUT
 	// Note: If it's OUT or INOUT, it must be a variable.
@@ -411,14 +416,11 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
     // The rest of the frame are local variables which are all IN.
     // Default all variables to null (those with default clauses will
     // be set by an set instruction).
+    for (; i < csize ; i++)
     {
-      Item_null *nit= NULL;	// Re-use this, and only create if needed
-      for (; i < csize ; i++)
-      {
-	if (! nit)
-	  nit= new Item_null();
-	nctx->push_item(nit);
-      }
+      if (! nit)
+	nit= new Item_null();
+      nctx->push_item(nit);
     }
     thd->spcont= nctx;
   }