suppress switch branch de-duplication upon side effects (#1682)

fixes #1679
2017-03-26 13:32:43 +08:00
parent 8a4f86528f
commit 94f84727ce
2 changed files with 50 additions and 1 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -2551,12 +2551,14 @@ merge(Compressor.prototype, {
                    } else {
                        body.push(branch);
                    }
-                    blocks[key] = branch;
                    fallthrough = false;
                } else {
                    body.push(branch);
                    fallthrough = true;
                }
+                if (branch instanceof AST_Case && branch.expression.has_side_effects(compressor))
+                    blocks = Object.create(null);
+                if (!fallthrough) blocks[key] = branch;
            }
            for (; i < len && fallthrough; i++) {
                branch = self.body[i];