fix corner case in `inilne` (#4204)

fixes #4202

2 files changed, 45 insertions, 12 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 3464a232..f6de8656 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -7198,24 +7198,24 @@ merge(Compressor.prototype, {
             return defined[name] || identifier_atom[name] || scope.var_names()[name];
         }
 
-        function can_inject_args(catches, used, safe_to_inject) {
+        function can_inject_args(defined, used, safe_to_inject) {
             for (var i = 0; i < fn.argnames.length; i++) {
                 var arg = fn.argnames[i];
                 if (arg.__unused) continue;
-                if (!safe_to_inject || var_exists(catches, arg.name)) return false;
+                if (!safe_to_inject || var_exists(defined, arg.name)) return false;
                 used[arg.name] = true;
                 if (in_loop) in_loop.push(arg.definition());
             }
             return true;
         }
 
-        function can_inject_vars(catches, used, safe_to_inject) {
+        function can_inject_vars(defined, used, safe_to_inject) {
             for (var i = 0; i < fn.body.length; i++) {
                 var stat = fn.body[i];
                 if (stat instanceof AST_Defun) {
                     if (!safe_to_inject || var_exists(used, stat.name.name)) return false;
                     if (!all(stat.enclosed, function(def) {
-                        return def.scope === stat || !catches[def.name];
+                        return def.scope === stat || !defined[def.name];
                     })) return false;
                     continue;
                 }
@@ -7223,7 +7223,7 @@ merge(Compressor.prototype, {
                 if (!safe_to_inject) return false;
                 for (var j = stat.definitions.length; --j >= 0;) {
                     var name = stat.definitions[j].name;
-                    if (var_exists(catches, name.name)) return false;
+                    if (var_exists(defined, name.name)) return false;
                     if (in_loop) in_loop.push(name.definition());
                 }
             }
@@ -7231,15 +7231,16 @@ merge(Compressor.prototype, {
         }
 
         function can_inject_symbols() {
-            var catches = Object.create(null);
+            var defined = Object.create(null);
             var child;
             scope = compressor.self();
             do {
                 child = scope;
                 scope = compressor.parent(++level);
-                if (scope instanceof AST_Catch) {
-                    if (scope.argname) catches[scope.argname.name] = true;
-                } else if (scope instanceof AST_DWLoop) {
+                if (scope.variables) scope.variables.each(function(def) {
+                    defined[def.name] = true;
+                });
+                if (scope instanceof AST_DWLoop) {
                     in_loop = [];
                 } else if (scope instanceof AST_For) {
                     if (scope.init === child) continue;
@@ -7255,9 +7256,9 @@ merge(Compressor.prototype, {
             var safe_to_inject = (!(scope instanceof AST_Toplevel) || compressor.toplevel.vars)
                 && (exp !== fn || fn.parent_scope.resolve() === compressor.find_parent(AST_Scope));
             var inline = compressor.option("inline");
-            var used = Object.create(catches);
-            if (!can_inject_args(catches, used, inline >= 2 && safe_to_inject)) return false;
-            if (!can_inject_vars(catches, used, inline >= 3 && safe_to_inject)) return false;
+            var used = Object.create(defined);
+            if (!can_inject_args(defined, used, inline >= 2 && safe_to_inject)) return false;
+            if (!can_inject_vars(defined, used, inline >= 3 && safe_to_inject)) return false;
             return !in_loop || in_loop.length == 0 || !is_reachable(fn, in_loop);
         }
 
diff --git a/test/compress/const.js b/test/compress/const.js
index 72033f4a..28dda019 100644
--- a/test/compress/const.js
+++ b/test/compress/const.js
@@ -840,3 +840,35 @@ issue_4198: {
     }
     expect_stdout: "PASS"
 }
+
+issue_4202: {
+    options = {
+        inline: true,
+        toplevel: true,
+    }
+    input: {
+        {
+            const o = {};
+            (function() {
+                function f() {
+                    o.p = 42;
+                }
+                f(f);
+            })();
+            console.log(o.p++);
+        }
+    }
+    expect: {
+        {
+            const o = {};
+            (function() {
+                function f() {
+                    o.p = 42;
+                }
+                f(f);
+            })();
+            console.log(o.p++);
+        }
+    }
+    expect_stdout: "42"
+}