fix corner cases with arrow functions (#4688)

fixes #4687

2 files changed, 212 insertions, 1 deletions

diff --git a/test/compress/arrows.js b/test/compress/arrows.js
index a3a46871..6cb55223 100644
--- a/test/compress/arrows.js
+++ b/test/compress/arrows.js
@@ -704,7 +704,7 @@ issue_4666: {
     node_version: ">=4"
 }
 
-issue_4685: {
+issue_4685_1: {
     options = {
         collapse_vars: true,
         unused: true,
@@ -724,3 +724,82 @@ issue_4685: {
     expect_stdout: "PASS"
     node_version: ">=4"
 }
+
+issue_4685_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        new function(f) {
+            if (f() !== this)
+                console.log("PASS");
+        }(() => {
+            if (console)
+                return this;
+        });
+    }
+    expect: {
+        new function(f) {
+            if (f() !== this)
+                console.log("PASS");
+        }(() => {
+            if (console)
+                return this;
+        });
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4687_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        new function() {
+            console.log(function(f) {
+                return f() === this;
+            }(() => this) || "PASS");
+        }
+    }
+    expect: {
+        new function() {
+            console.log(function(f) {
+                return f() === this;
+            }(() => this) || "PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4687_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        new function() {
+            console.log(function(f) {
+                return f() === this;
+            }(() => {
+                if (console)
+                    return this;
+            }) || "PASS");
+        }
+    }
+    expect: {
+        new function() {
+            console.log(function(f) {
+                return f() === this;
+            }(() => {
+                if (console)
+                    return this;
+            }) || "PASS");
+        }
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
diff --git a/test/compress/classes.js b/test/compress/classes.js
index 95b4037d..ab2652c8 100644
--- a/test/compress/classes.js
+++ b/test/compress/classes.js
@@ -615,3 +615,135 @@ issue_4683: {
     expect_stdout: "PASS"
     node_version: ">=4"
 }
+
+issue_4685_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        new class {
+            f() {
+                (function(g) {
+                    if (g() !== this)
+                        console.log("PASS");
+                })(() => this);
+            }
+        }().f();
+    }
+    expect: {
+        "use strict";
+        new class {
+            f() {
+                (function(g) {
+                    if (g() !== this)
+                        console.log("PASS");
+                })(() => this);
+            }
+        }().f();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4685_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        new class {
+            f() {
+                (function(g) {
+                    if (g() !== this)
+                        console.log("PASS");
+                })(() => {
+                    if (console)
+                        return this;
+                });
+            }
+        }().f();
+    }
+    expect: {
+        "use strict";
+        new class {
+            f() {
+                (function(g) {
+                    if (g() !== this)
+                        console.log("PASS");
+                })(() => {
+                    if (console)
+                        return this;
+                });
+            }
+        }().f();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4687_1: {
+    options = {
+        collapse_vars: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        new class {
+            f() {
+                console.log(function(g) {
+                    return g() === this;
+                }(() => this) || "PASS");
+            }
+        }().f();
+    }
+    expect: {
+        "use strict";
+        new class {
+            f() {
+                console.log(function(g) {
+                    return g() === this;
+                }(() => this) || "PASS");
+            }
+        }().f();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}
+
+issue_4687_2: {
+    options = {
+        reduce_vars: true,
+        unused: true,
+    }
+    input: {
+        "use strict";
+        new class {
+            f() {
+                console.log(function(g) {
+                    return g() === this;
+                }(() => {
+                    if (console)
+                        return this;
+                }) || "PASS");
+            }
+        }().f();
+    }
+    expect: {
+        "use strict";
+        new class {
+            f() {
+                console.log(function(g) {
+                    return g() === this;
+                }(() => {
+                    if (console)
+                        return this;
+                }) || "PASS");
+            }
+        }().f();
+    }
+    expect_stdout: "PASS"
+    node_version: ">=4"
+}