fix corner case in `unsafe_regexp` (#3609)

1 files changed, 14 insertions, 4 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 46a7816e..19fba0b6 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -362,6 +362,7 @@ merge(Compressor.prototype, {
         function reset_def(tw, compressor, def) {
             def.assignments = 0;
             def.chained = false;
+            def.cross_loop = false;
             def.direct_access = false;
             def.escaped = [];
             def.fixed = !def.scope.pinned()
@@ -765,6 +766,9 @@ merge(Compressor.prototype, {
                         d.fixed = false;
                     }
                 }
+                if (d.fixed && tw.loop_ids[d.id] !== tw.in_loop) {
+                    d.cross_loop = true;
+                }
                 mark_escaped(tw, d, this.scope, this, value, 0, 1);
             }
             var parent;
@@ -6494,14 +6498,13 @@ merge(Compressor.prototype, {
             if (fixed && def.should_replace === undefined) {
                 var init;
                 if (fixed instanceof AST_This) {
-                    if (!(def.orig[0] instanceof AST_SymbolFunarg) && all(def.references, function(ref) {
-                        return def.scope === ref.scope;
-                    })) {
+                    if (!(def.orig[0] instanceof AST_SymbolFunarg) && same_scope(def)) {
                         init = fixed;
                     }
                 } else {
                     var ev = fixed.evaluate(compressor);
-                    if (ev !== fixed && (compressor.option("unsafe_regexp") || !(ev instanceof RegExp))) {
+                    if (ev !== fixed && (!(ev instanceof RegExp)
+                        || compressor.option("unsafe_regexp") && !def.cross_loop && same_scope(def))) {
                         init = make_node_from_constant(ev, fixed);
                     }
                 }
@@ -6538,6 +6541,13 @@ merge(Compressor.prototype, {
         }
         return self;
 
+        function same_scope(def) {
+            var scope = def.scope.resolve();
+            return all(def.references, function(ref) {
+                return scope === ref.scope.resolve();
+            });
+        }
+
         function has_symbol_ref(value) {
             var found;
             value.walk(new TreeWalker(function(node) {