fix corner cases in inline (#5252)

fixes #5249
fixes #5250

lib/compress.js

@@ -12831,7 +12831,36 @@ Compressor.prototype.compress = function(node) {
         def(AST_Node, noop);
         def(AST_Assign, noop);
         def(AST_Await, function(compressor, scope, no_return, in_loop) {
-            return this.expression.try_inline(compressor, scope, no_return, in_loop);
+            var self = this;
+            var inlined = sync(self.expression).try_inline(compressor, scope, no_return, in_loop);
+            if (!inlined) return;
+            return aborts(inlined) ? inlined : make_node(AST_BlockStatement, self, {
+                body: [ inlined, make_node(AST_SimpleStatement, self, {
+                    body: make_node(AST_Await, self, { expression: make_node(AST_Number, self, { value: 0 })}),
+                }) ],
+            });
+
+            function sync(node) {
+                if (!no_return) return node;
+                if (node.TYPE != "Call") return node;
+                var fn = node.expression;
+                switch (fn.CTOR) {
+                  case AST_AsyncArrow:
+                    fn = make_node(AST_Arrow, fn, fn);
+                    break;
+                  case AST_AsyncFunction:
+                    fn = make_node(AST_Function, fn, fn);
+                    break;
+                  case AST_AsyncGeneratorFunction:
+                    fn = make_node(AST_GeneratorFunction, fn, fn);
+                    break;
+                  default:
+                    return node;
+                }
+                node = node.clone();
+                node.expression = fn;
+                return node;
+            }
         });
         def(AST_Binary, function(compressor, scope, no_return, in_loop) {
             if (no_return === undefined) return;
@@ -12843,7 +12872,7 @@ Compressor.prototype.compress = function(node) {
             return make_node(AST_If, self, {
                 condition: make_condition(self.left),
                 body: inlined,
-                alternative: null,
+                alternative: no_return ? null : make_node(AST_Return, self, { value: null }),
             });
 
             function make_condition(cond) {

test/compress/awaits.js

@@ -512,6 +512,42 @@ inline_block_await: {
 }
 
 inline_block_await_async: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (async function() {
+            console.log("foo");
+            await (async function() {
+                while (await console.log("bar"));
+                console.log("baz");
+            })();
+            console.log("moo");
+        })().then(console.log);
+        console.log("moz");
+    }
+    expect: {
+        (async function() {
+            console.log("foo");
+            while (await console.log("bar"));
+            console.log("baz");
+            await 0;
+            console.log("moo");
+        })().then(console.log);
+        console.log("moz");
+    }
+    expect_stdout: [
+        "foo",
+        "bar",
+        "moz",
+        "baz",
+        "moo",
+        "undefined",
+    ]
+    node_version: ">=8"
+}
+
+inline_block_await_async_return: {
     options = {
         awaits: true,
         if_return: true,
@@ -2540,3 +2576,32 @@ issue_5177: {
     expect_stdout: "function"
     node_version: ">=8"
 }
+
+issue_5250: {
+    options = {
+        inline: true,
+    }
+    input: {
+        (async function() {
+            await function() {
+                while (console.log("foo"));
+            }();
+            console.log("bar");
+        })();
+        console.log("baz");
+    }
+    expect: {
+        (async function() {
+            while (console.log("foo"));
+            await 0;
+            console.log("bar");
+        })();
+        console.log("baz");
+    }
+    expect_stdout: [
+        "foo",
+        "baz",
+        "bar",
+    ]
+    node_version: ">=8"
+}

test/compress/functions.js

@@ -628,7 +628,8 @@ inline_binary_and: {
                 while (console.log("baz"));
                 return void "moo";
                 return;
-            }
+            } else
+                return;
         }());
     }
     expect_stdout: [
@@ -7686,3 +7687,66 @@ issue_5240_2: {
     }
     expect_stdout: "undefined"
 }
+
+issue_5249_1: {
+    options = {
+        inline: true,
+    }
+    input: {
+        console.log(function() {
+            if (!console)
+                var a = "FAIL 1";
+            else
+                return void (a && function() {
+                    while (console.log("FAIL 2"));
+                }());
+            throw "FAIL 3";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            if (!console)
+                var a = "FAIL 1";
+            else if (a) {
+                while (console.log("FAIL 2"));
+                return;
+            } else
+                return;
+            throw "FAIL 3";
+        }());
+    }
+    expect_stdout: "undefined"
+}
+
+issue_5249_2: {
+    options = {
+        conditionals: true,
+        dead_code: true,
+        evaluate: true,
+        if_return: true,
+        inline: true,
+        passes: 3,
+        reduce_vars: true,
+        sequences: true,
+        side_effects: true,
+        unused: true,
+    }
+    input: {
+        console.log(function() {
+            if (!console)
+                var a = "FAIL 1";
+            else
+                return void (a && function() {
+                    while (console.log("FAIL 2"));
+                }());
+            throw "FAIL 3";
+        }());
+    }
+    expect: {
+        console.log(function() {
+            if (!console)
+                throw "FAIL 3";
+        }());
+    }
+    expect_stdout: "undefined"
+}