improve exceptional flow compression by `collapse_vars` (#2880)

1 files changed, 3 insertions, 10 deletions

diff --git a/lib/compress.js b/lib/compress.js
index f9cd7a41..321ee5fc 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1408,22 +1408,15 @@ merge(Compressor.prototype, {
             }
 
             function side_effects_external(node, lhs) {
-                if (node instanceof AST_Assign) {
-                    return side_effects_external(node.left, true)
-                        || side_effects_external(node.right);
-                }
-                if (node instanceof AST_Definitions) return false;
+                if (node instanceof AST_Assign) return side_effects_external(node.left, true);
                 if (node instanceof AST_Unary) return side_effects_external(node.expression, true);
                 if (node instanceof AST_VarDef) return node.value && side_effects_external(node.value);
                 if (lhs) {
                     if (node instanceof AST_Dot) return side_effects_external(node.expression, true);
-                    if (node instanceof AST_Sub) {
-                        return side_effects_external(node.expression, true)
-                            || side_effects_external(node.property);
-                    }
+                    if (node instanceof AST_Sub) return side_effects_external(node.expression, true);
                     if (node instanceof AST_SymbolRef) return node.definition().scope !== scope;
                 }
-                return node.has_side_effects(compressor);
+                return false;
             }
         }