fix corner case in inline (#5886)

fixes #5884

Author: alexlamsl

lib/compress.js

@@ -1653,6 +1653,7 @@ Compressor.prototype.compress = function(node) {
     function reset_flags(node) {
         node._squeezed = false;
         node._optimized = false;
+        node.single_use = false;
         if (node instanceof AST_BlockScope) node._var_names = undefined;
         if (node instanceof AST_SymbolRef) node.fixed = undefined;
     }
@@ -14178,6 +14179,7 @@ Compressor.prototype.compress = function(node) {
             var fn = call.expression;
             if (!(fn instanceof AST_LambdaExpression)) return;
             if (fn.name) return;
+            if (fn.single_use) return;
             if (fn.uses_arguments) return;
             if (fn.pinned()) return;
             if (is_generator(fn)) return;

test/compress/functions.js

@@ -8706,10 +8706,9 @@ single_use_inline_collision: {
     expect: {
         var a = "PASS";
         (function() {
-            (function() {
+            void function() {
                 while (console.log(a));
-                return;
-            })();
+            }();
             (function(a) {
                 a || a("FAIL");
             })(console.log);

test/compress/hoist_vars.js

@@ -801,3 +801,71 @@ issue_5638_4: {
     }
     expect_stdout: "foo 42"
 }
+
+issue_5884_1: {
+    options = {
+        hoist_vars: true,
+        inline: true,
+        join_vars: true,
+        reduce_vars: true,
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            var f = function() {
+                var a = [ "PASS" ];
+                for (b in a)
+                    console.log(a[b]);
+            };
+            f();
+        } finally {
+            var b;
+        }
+    }
+    expect: {
+        var b;
+        try {
+            (function() {
+                var a = [ "PASS" ];
+                for (b in a)
+                    console.log(a[b]);
+            })();
+        } finally {}
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5884_2: {
+    options = {
+        hoist_vars: true,
+        inline: true,
+        join_vars: true,
+        passes: 2,
+        reduce_vars: true,
+        sequences: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        try {
+            var f = function() {
+                var a = [ "PASS" ];
+                for (b in a)
+                    console.log(a[b]);
+            };
+            f();
+        } finally {
+            var b;
+        }
+    }
+    expect: {
+        try {
+            var a = [ "PASS" ];
+            for (var b in a)
+                console.log(a[b]);
+        } finally {}
+    }
+    expect_stdout: "PASS"
+}

test/compress/join_vars.js

@@ -669,7 +669,7 @@ inlined_assignments: {
     expect_stdout: "PASS"
 }
 
-inline_for: {
+single_use_for: {
     options = {
         inline: true,
         join_vars: true,
@@ -683,16 +683,66 @@ inline_for: {
         };
         a();
     }
+    expect: {
+        (function() {
+            for (; console.log("PASS"););
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+single_use_for_inline: {
+    options = {
+        inline: true,
+        join_vars: true,
+        passes: 2,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        var a = function() {
+            for (; console.log("PASS"););
+        };
+        a();
+    }
     expect: {
         for (; console.log("PASS"););
     }
     expect_stdout: "PASS"
 }
 
-inline_var: {
+single_use_var: {
+    options = {
+        inline: true,
+        join_vars: true,
+        reduce_vars: true,
+        toplevel: true,
+        unused: true,
+    }
+    input: {
+        A = "PASS";
+        var a = function() {
+            var b = A;
+            for (b in console.log(b));
+        };
+        a();
+    }
+    expect: {
+        A = "PASS";
+        (function() {
+            var b = A;
+            for (b in console.log(b));
+        })();
+    }
+    expect_stdout: "PASS"
+}
+
+single_use_var_inline: {
     options = {
         inline: true,
         join_vars: true,
+        passes: 2,
         reduce_vars: true,
         toplevel: true,
         unused: true,