fix case where loopvar is redefined with an explicit i := i define (p…

…re 1.22 fix for loopvar) with the same name as the original. all the other tests were using a new variable name, so we missed this case.

_test/closure19.go

@@ -0,0 +1,18 @@
+package main
+
+func main() {
+	foos := []func(){}
+
+	for i := 0; i < 3; i++ {
+		i := i
+		foos = append(foos, func() { println(i) })
+	}
+	foos[0]()
+	foos[1]()
+	foos[2]()
+}
+
+// Output:
+// 0
+// 1
+// 2

_test/closure20.go

@@ -0,0 +1,18 @@
+package main
+
+func main() {
+	foos := []func(){}
+
+	for i := range 3 {
+		i := i
+		foos = append(foos, func() { println(i) })
+	}
+	foos[0]()
+	foos[1]()
+	foos[2]()
+}
+
+// Output:
+// 0
+// 1
+// 2

interp/cfg.go

@@ -734,6 +734,22 @@ func (interp *Interpreter) cfg(root *node, sc *scope, importPath, pkgName string
 						return
 					}
 					if sc.global || sc.isRedeclared(dest) {
+						if n.anc != nil && n.anc.anc != nil && (n.anc.anc.kind == forStmt7 || n.anc.anc.kind == rangeStmt) {
+							// check for redefine of for loop variables, which are now auto-defined in go1.22
+							init := n.anc.anc.child[0]
+							var fi *node // for ident
+							if n.anc.anc.kind == forStmt7 {
+								if init.kind == defineStmt && len(init.child) >= 2 && init.child[0].kind == identExpr {
+									fi = init.child[0]
+								}
+							} else { // range
+								fi = init
+							}
+							if fi != nil && dest.ident == fi.ident {
+								n.gen = nop
+								break
+							}
+						}
 						// Do not overload existing symbols (defined in GTA) in global scope.
 						sym, _, _ = sc.lookup(dest.ident)
 					}