fix corner case in `evaluate` (#3728)

- augment `ufuzz` for further `RegExp` testing

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/compress.js b/lib/compress.js
index e8a71791..23c73048 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -315,7 +315,7 @@ merge(Compressor.prototype, {
         if (value instanceof AST_Array) return native_fns.Array[name];
         if (value instanceof AST_Function) return native_fns.Function[name];
         if (value instanceof AST_Object) return native_fns.Object[name];
-        if (value instanceof AST_RegExp) return native_fns.RegExp[name];
+        if (value instanceof AST_RegExp) return native_fns.RegExp[name] && !value.value.global;
     }
 
     function is_modified(compressor, tw, node, value, level, immutable) {
@@ -3003,6 +3003,7 @@ merge(Compressor.prototype, {
         ].concat(object_fns),
         Object: object_fns,
         RegExp: [
+            "exec",
             "test",
         ].concat(object_fns),
         String: [
@@ -3085,6 +3086,7 @@ merge(Compressor.prototype, {
             cached.forEach(function(node) {
                 delete node._eval;
             });
+            if (ignore_side_effects) return val;
             if (!val || val instanceof RegExp) return val;
             if (typeof val == "function" || typeof val == "object") return this;
             return val;
@@ -3400,6 +3402,7 @@ merge(Compressor.prototype, {
                     if (val == null || val === e) return this;
                     var native_fn = native_fns[val.constructor.name];
                     if (!native_fn || !native_fn[key]) return this;
+                    if (val instanceof RegExp && val.global && !(e instanceof AST_RegExp)) return this;
                 }
                 var args = eval_args(this.args);
                 if (!args) return this;