fix corner cases in if_return (#5590)

fixes #5589
fixes #5591
fixes #5592

lib/compress.js

@@ -3664,17 +3664,19 @@ Compressor.prototype.compress = function(node) {
                     var value = ab.value;
                     if (value && !is_undefined(value.tail_node())) return false;
                     if (!(self instanceof AST_SwitchBranch)) return true;
-                    if (jump instanceof AST_Break) {
+                    if (!jump) return false;
-                        merge_jump = 4;
+                    if (jump instanceof AST_Exit && jump.value) return false;
-                    } else if (jump instanceof AST_Exit && !jump.value) {
+                    merge_jump = 4;
-                        merge_jump = true;
-                    }
                     return true;
                 }
                 if (!(ab instanceof AST_LoopControl)) return false;
                 if (jump && self instanceof AST_SwitchBranch) {
-                    if (jump instanceof AST_Exit && jump.value) return false;
+                    if (jump instanceof AST_Exit) {
-                    if (compressor.loopcontrol_target(jump) instanceof AST_IterationStatement) return false;
+                        if (!in_lambda) return false;
+                        if (jump.value) return false;
+                    } else if (compressor.loopcontrol_target(jump) !== parent) {
+                        return false;
+                    }
                     merge_jump = true;
                 }
                 var lct = compressor.loopcontrol_target(ab);

test/compress/const.js

@@ -2096,3 +2096,51 @@ issue_5580_2: {
     expect_stdout: "PASS"
     node_version: ">=4"
 }
+
+issue_5591: {
+    options = {
+        dead_code: true,
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console.log("baz"))
+                    return;
+                else {
+                    const a = 42;
+                    return;
+                }
+                break;
+              case null:
+                FAIL;
+            }
+        }
+        f();
+    }
+    expect: {
+        "use strict";
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console.log("baz"))
+                    return;
+                else {
+                    const a = 42;
+                    return;
+                }
+              case null:
+                FAIL;
+            }
+        }
+        f();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=4"
+}

test/compress/if_return.js

@@ -1759,8 +1759,7 @@ issue_5584_1: {
         function f(a) {
             switch (a) {
               case 42:
-                if (console.log("PASS"))
+                return console.log("PASS") ? FAIL : void 0;
-                    return FAIL;
             }
         }
         f(42);
@@ -1775,7 +1774,7 @@ issue_5584_2: {
     input: {
         function f(a) {
             switch (a) {
-            case console.log("PASS"):
+              case console.log("PASS"):
                 if (console)
                     break;
                 return FAIL;
@@ -1786,7 +1785,7 @@ issue_5584_2: {
     expect: {
         function f(a) {
             switch (a) {
-            case console.log("PASS"):
+              case console.log("PASS"):
                 if (console)
                     break;
                 return FAIL;
@@ -1797,6 +1796,76 @@ issue_5584_2: {
     expect_stdout: "PASS"
 }
 
+issue_5584_3: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        function f() {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console)
+                    break;
+                return;
+            }
+            console.log("baz");
+        }
+        f();
+    }
+    expect: {
+        function f() {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console)
+                    break;
+                return;
+            }
+            console.log("baz");
+        }
+        f();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
+issue_5584_4: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (a)
+                    return;
+                break;
+            }
+            console.log("baz");
+        }
+        f();
+    }
+    expect: {
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (a)
+                    return;
+                break;
+            }
+            console.log("baz");
+        }
+        f();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
 issue_5586: {
     options = {
         if_return: true,
@@ -1871,3 +1940,182 @@ issue_5587_2: {
     }
     expect_stdout: "PASS"
 }
+
+issue_5589_1: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        function f(a) {
+            switch (a) {
+              case 42:
+                if (!console.log("PASS"))
+                    return;
+                return 0;
+                break;
+              case null:
+                FAIL;
+            }
+        }
+        f(42);
+    }
+    expect: {
+        function f(a) {
+            switch (a) {
+              case 42:
+                if (console.log("PASS"))
+                    return 0;
+                break;
+              case null:
+                FAIL;
+            }
+        }
+        f(42);
+    }
+    expect_stdout: "PASS"
+}
+
+issue_5589_2: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (a)
+                    return void console.log("baz");
+                return;
+            }
+        }
+        f();
+        f(42);
+    }
+    expect: {
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (a)
+                    void console.log("baz");
+                return;
+            }
+        }
+        f();
+        f(42);
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
+issue_5589_3: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        function f(a) {
+            do {
+                switch (console.log("foo")) {
+                  case console.log("bar"):
+                    if (a)
+                        return void console.log("baz");
+                    continue;
+                }
+            } while (console.log("moo"));
+        }
+        f();
+        f(42);
+    }
+    expect: {
+        function f(a) {
+            do {
+                switch (console.log("foo")) {
+                  case console.log("bar"):
+                    if (a)
+                        return void console.log("baz");
+                    continue;
+                }
+            } while (console.log("moo"));
+        }
+        f();
+        f(42);
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "moo",
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
+issue_5592_1: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        L: {
+            do {
+                switch (console.log("foo")) {
+                  case console.log("bar"):
+                    if (console)
+                        break;
+                    break L;
+                }
+            } while (console.log("baz"));
+        }
+    }
+    expect: {
+        L: do {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console)
+                    break;
+                break L;
+            }
+        } while (console.log("baz"));
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+}
+
+issue_5592_2: {
+    options = {
+        if_return: true,
+    }
+    input: {
+        L: {
+            do {
+                switch (console.log("foo")) {
+                  case console.log("bar"):
+                    if (!console)
+                        break L;
+                    break;
+                }
+            } while (console.log("baz"));
+        }
+    }
+    expect: {
+        L: do {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console)
+                    break;
+                break L;
+            }
+        } while (console.log("baz"));
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+}

test/compress/let.js

@@ -2122,3 +2122,51 @@ issue_5476: {
     expect_stdout: "undefined"
     node_version: ">=4"
 }
+
+issue_5591: {
+    options = {
+        dead_code: true,
+        if_return: true,
+    }
+    input: {
+        "use strict";
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console.log("baz"))
+                    return;
+                else {
+                    let a;
+                    return;
+                }
+                break;
+              case null:
+                FAIL;
+            }
+        }
+        f();
+    }
+    expect: {
+        "use strict";
+        function f(a) {
+            switch (console.log("foo")) {
+              case console.log("bar"):
+                if (console.log("baz"))
+                    return;
+                else {
+                    let a;
+                    return;
+                }
+              case null:
+                FAIL;
+            }
+        }
+        f();
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "baz",
+    ]
+    node_version: ">=4"
+}