enhance `if_return` (#4164)

1 files changed, 14 insertions, 5 deletions

diff --git a/lib/compress.js b/lib/compress.js
index dfe444ad..df797bf7 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -2150,7 +2150,9 @@ merge(Compressor.prototype, {
         function handle_if_return(statements, compressor) {
             var self = compressor.self();
             var parent = compressor.parent();
-            var in_lambda = self instanceof AST_Lambda;
+            var in_lambda = last_of(function(node) {
+                return node instanceof AST_Lambda;
+            });
             var in_iife = in_lambda && parent && parent.TYPE == "Call";
             var multiple_if_returns = has_multiple_if_returns(statements);
             for (var i = statements.length; --i >= 0;) {
@@ -2253,7 +2255,7 @@ merge(Compressor.prototype, {
                     }
                     //---
                     // if (foo()) return x; return y; => return foo() ? x : y;
-                    if ((in_bool || value) && !stat.alternative && next instanceof AST_Return) {
+                    if (!stat.alternative && next instanceof AST_Return) {
                         CHANGED = true;
                         stat = stat.clone();
                         stat.alternative = next;
@@ -2323,14 +2325,21 @@ merge(Compressor.prototype, {
                 return true;
             }
 
-            function match_target(target) {
+            function last_of(predicate) {
                 var block = self, stat, level = 0;
                 do {
                     do {
-                        if (block === target) return true;
+                        if (predicate(block)) return true;
                         block = compressor.parent(level++);
                     } while (block instanceof AST_If && (stat = block));
-                } while (block instanceof AST_BlockStatement && is_last_statement(block.body, stat));
+                } while ((block instanceof AST_BlockStatement || block instanceof AST_Scope)
+                    && is_last_statement(block.body, stat));
+            }
+
+            function match_target(target) {
+                return last_of(function(node) {
+                    return node === target;
+                });
             }
 
             function can_merge_flow(ab) {