fix corner case in inline (#5537)

fixes #5536

lib/compress.js

@@ -1598,8 +1598,7 @@ Compressor.prototype.compress = function(node) {
     AST_Destructured.DEFMETHOD("convert_symbol", convert_destructured);
     function convert_symbol(type, process) {
         var node = make_node(type, this, this);
-        process(node, this);
-        return node;
+        return process(node, this) || node;
     }
     AST_SymbolDeclaration.DEFMETHOD("convert_symbol", convert_symbol);
     AST_SymbolRef.DEFMETHOD("convert_symbol", convert_symbol);
@@ -10548,9 +10547,9 @@ Compressor.prototype.compress = function(node) {
         return try_evaluate(compressor, self);
 
         function make_void_lhs(orig) {
-            return make_node(AST_Dot, orig, {
+            return make_node(AST_Sub, orig, {
                 expression: make_node(AST_Array, orig, { elements: [] }),
-                property: "e",
+                property: make_node(AST_Number, orig, { value: 0 }),
             });
         }
 
@@ -10905,6 +10904,7 @@ Compressor.prototype.compress = function(node) {
             }));
 
             function process(ref, name) {
+                if (name.unused) return make_void_lhs(name);
                 var def = name.definition();
                 def.assignments++;
                 def.references.push(ref);

test/compress/default-values.js

@@ -541,7 +541,7 @@ inline_side_effects_2: {
     }
     expect: {
         var a = 42;
-        [ [].e = --a ] = [ console ];
+        [ [][0] = --a ] = [ console ];
         console.log(a);
     }
     expect_stdout: "42"
@@ -1558,7 +1558,7 @@ issue_4502_4: {
         (function(a, b = console.log("FAIL")) {})(..."" + console.log(42));
     }
     expect: {
-        [ , [].e = console.log("FAIL") ] = [ ..."" + console.log(42) ];
+        [ , [][0] = console.log("FAIL") ] = [ ..."" + console.log(42) ];
     }
     expect_stdout: "42"
     node_version: ">=6"
@@ -2183,7 +2183,7 @@ issue_5340_2: {
     }
     expect: {
         var a;
-        [ [].e = 0 ] = [ ({ p: a } = true).q ];
+        [ [][0] = 0 ] = [ ({ p: a } = true).q ];
         console.log(a);
     }
     expect_stdout: "undefined"
@@ -2806,3 +2806,26 @@ issue_5533_4_drop_fargs: {
     expect_stdout: "PASS"
     node_version: ">=6"
 }
+
+issue_5536: {
+    options = {
+        inline: true,
+        keep_fargs: true,
+        unused: true,
+    }
+    input: {
+        (function*() {
+            (([], a = 42) => {})([]);
+            console.log(typeof a);
+        })().next();
+    }
+    expect: {
+        (function*() {
+            [ , [][0] = 0 ] = [ [] ],
+            void 0;
+            console.log(typeof a);
+        })().next();
+    }
+    expect_stdout: "undefined"
+    node_version: ">=6"
+}

test/compress/destructured.js

@@ -3497,7 +3497,7 @@ issue_5314_2: {
         A = this;
         new function() {
             [ {
-                [console.log(this === A ? "FAIL" : "PASS")]: [].e,
+                [console.log(this === A ? "FAIL" : "PASS")]: [][0],
             } ] = [ 42 ];
         }();
     }

test/compress/rests.js

@@ -648,7 +648,7 @@ drop_new_function: {
     }
     expect: {
         void ([ ... {
-            [console.log("PASS")]: [].e,
+            [console.log("PASS")]: [][0],
         }] = []);
     }
     expect_stdout: "PASS"

test/compress/yields.js

@@ -907,7 +907,7 @@ drop_body: {
         })([ console.log("baz") ]);
     }
     expect: {
-        [ [ , [].e = console.log("foo") ] ] = [ [ console.log("baz") ] ];
+        [ [ , [][0] = console.log("foo") ] ] = [ [ console.log("baz") ] ];
     }
     expect_stdout: [
         "baz",