JS: fix bug in var decl merging with for-in statements, fixes #619

tdewolff · Oct 26, 2023 · 8e38b17 · 8e38b17
1 parent 2e816a4
commit 8e38b17
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Showing 2 changed files with 8 additions and 5 deletions.
diff --git a/js/js_test.go b/js/js_test.go
@@ -800,6 +800,7 @@ func TestJS(t *testing.T) {
 		{`export default function Foo(){a}Foo.prototype.bar=b`, `export default function Foo(){a}Foo.prototype.bar=b`},                                     // #525
 		{`(e=1,e=2)`, `e=1,e=2`},                  // #528
 		{`"\x00\x31 \0\u0000"`, `"\x001 \0\x00"`}, // #577
+		{`function transform(){{var aaaa=[];for(var b=0;;){}for(var b in aaaa){}var aaaa=[];for(var b=0;;){}}}`, `function transform(){{for(var aaaa=[],b=0;;);for(b in aaaa);for(aaaa=[],b=0;;)}}`}, // #619
 	}
 
 	m := minify.New()

diff --git a/js/vars.go b/js/vars.go
@@ -206,11 +206,13 @@ RemoveVarsLoop:
 		if value != nil {
 			// variable declaration must be somewhere else, find and remove it
 			for _, decl2 := range decl.Scope.Func.VarDecls {
-				for i, item := range decl2.List {
-					if v, ok := item.Binding.(*js.Var); ok && item.Default == nil && v == vbind {
-						v.Uses--
-						decl2.List = append(decl2.List[:i], decl2.List[i+1:]...)
-						continue RemoveVarsLoop
+				if !decl2.InForInOf {
+					for i, item := range decl2.List {
+						if v, ok := item.Binding.(*js.Var); ok && item.Default == nil && v == vbind {
+							v.Uses--
+							decl2.List = append(decl2.List[:i], decl2.List[i+1:]...)
+							continue RemoveVarsLoop
+						}
 					}
 				}
 			}