fix `reduce_vars` on boolean binary expressions (#1819)

Side effects of `&&` and `||` have not mattered until #1814, which takes assignment expressions into account.

1 files changed, 8 insertions, 0 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 7324fe0e..f49dd60e 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -340,6 +340,14 @@ merge(Compressor.prototype, {
                         });
                     }
                 }
+                if (node instanceof AST_Binary
+                    && (node.operator == "&&" || node.operator == "||")) {
+                    node.left.walk(tw);
+                    push();
+                    node.right.walk(tw);
+                    pop();
+                    return true;
+                }
                 if (node instanceof AST_If) {
                     node.condition.walk(tw);
                     push();