Fix invalid removal of left side in && and || compression

See #637. This does not produce the optimal result, but it does prevent the removal of non-side-effect-free code.

1 files changed, 22 insertions, 0 deletions

diff --git a/test/compress/issue-637.js b/test/compress/issue-637.js
new file mode 100644
index 00000000..45fd2481
--- /dev/null
+++ b/test/compress/issue-637.js
@@ -0,0 +1,22 @@
+wrongly_optimized: {
+    options = {
+        conditionals: true,
+        booleans: true,
+        evaluate: true
+    };
+    input: {
+        function func() {
+            foo();
+        }
+        if (func() || true) {
+            bar();
+        }
+    }
+    expect: {
+        function func() {
+            foo();
+        }
+        // TODO: optimize to `func(), bar()`
+        (func(), 0) || bar();
+    }
+}