avoid suboptimal termination in `passes` (#2787)

diff --git a/lib/compress.js b/lib/compress.js
index 7e3503f..a461cb0 100644 (file)
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -171,7 +171,8 @@ merge(Compressor.prototype, {
             node.process_expression(true);
         }
         var passes = +this.options.passes || 1;
-        var last_count = 1 / 0;
+        var min_count = 1 / 0;
+        var stopping = false;
         var mangle = { ie8: this.option("ie8") };
         for (var pass = 0; pass < passes; pass++) {
             node.figure_out_scope(mangle);
@@ -183,9 +184,15 @@ merge(Compressor.prototype, {
                 node.walk(new TreeWalker(function() {
                     count++;
                 }));
-                this.info("pass " + pass + ": last_count: " + last_count + ", count: " + count);
-                if (count >= last_count) break;
-                last_count = count;
+                this.info("pass " + pass + ": last_count: " + min_count + ", count: " + count);
+                if (count < min_count) {
+                    min_count = count;
+                    stopping = false;
+                } else if (stopping) {
+                    break;
+                } else {
+                    stopping = true;
+                }
             }
         }
         if (this.option("expression")) {