1 files changed, 14 insertions, 19 deletions
diff --git a/prog/clone.go b/prog/clone.go
index 2253c7e75..1ff42f60f 100644
--- a/prog/clone.go
+++ b/prog/clone.go
@@ -4,33 +4,30 @@
 package prog
 
 func (p *Prog) Clone() *Prog {
-	p1, _ := p.cloneImpl(false)
-	return p1
-}
-
-func (p *Prog) cloneImpl(full bool) (*Prog, map[Arg]Arg) {
 	p1 := &Prog{
 		Target: p.Target,
+		Calls:  make([]*Call, len(p.Calls)),
 	}
 	newargs := make(map[Arg]Arg)
-	for _, c := range p.Calls {
+	for ci, c := range p.Calls {
 		c1 := new(Call)
 		c1.Meta = c.Meta
-		c1.Ret = clone(c.Ret, newargs, full)
-		for _, arg := range c.Args {
-			c1.Args = append(c1.Args, clone(arg, newargs, full))
+		c1.Ret = clone(c.Ret, newargs)
+		c1.Args = make([]Arg, len(c.Args))
+		for ai, arg := range c.Args {
+			c1.Args[ai] = clone(arg, newargs)
 		}
-		p1.Calls = append(p1.Calls, c1)
+		p1.Calls[ci] = c1
 	}
 	if debug {
 		if err := p1.validate(); err != nil {
 			panic(err)
 		}
 	}
-	return p1, newargs
+	return p1
 }
 
-func clone(arg Arg, newargs map[Arg]Arg, full bool) Arg {
+func clone(arg Arg, newargs map[Arg]Arg) Arg {
 	var arg1 Arg
 	switch a := arg.(type) {
 	case *ConstArg:
@@ -42,7 +39,7 @@ func clone(arg Arg, newargs map[Arg]Arg, full bool) Arg {
 		*a1 = *a
 		arg1 = a1
 		if a.Res != nil {
-			a1.Res = clone(a.Res, newargs, full)
+			a1.Res = clone(a.Res, newargs)
 		}
 	case *DataArg:
 		a1 := new(DataArg)
@@ -53,15 +50,15 @@ func clone(arg Arg, newargs map[Arg]Arg, full bool) Arg {
 		a1 := new(GroupArg)
 		*a1 = *a
 		arg1 = a1
-		a1.Inner = nil
-		for _, arg2 := range a.Inner {
-			a1.Inner = append(a1.Inner, clone(arg2, newargs, full))
+		a1.Inner = make([]Arg, len(a.Inner))
+		for i, arg2 := range a.Inner {
+			a1.Inner[i] = clone(arg2, newargs)
 		}
 	case *UnionArg:
 		a1 := new(UnionArg)
 		*a1 = *a
 		arg1 = a1
-		a1.Option = clone(a.Option, newargs, full)
+		a1.Option = clone(a.Option, newargs)
 	case *ResultArg:
 		a1 := new(ResultArg)
 		*a1 = *a
@@ -85,8 +82,6 @@ func clone(arg Arg, newargs map[Arg]Arg, full bool) Arg {
 	if used, ok := arg1.(ArgUsed); ok {
 		*used.Used() = nil // filled when we clone the referent
 		newargs[arg] = arg1
-	} else if full {
-		newargs[arg] = arg1
 	}
 	return arg1
 }