enhance merge_vars (#5308)

mishoo · Jan 21, 2022 · 866cd4a · 866cd4a
1 parent e24b255
commit 866cd4a
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Showing 2 changed files with 6 additions and 10 deletions.
diff --git a/lib/compress.js b/lib/compress.js
@@ -6245,8 +6245,10 @@ Compressor.prototype.compress = function(node) {
                     || !mergeable(head_refs, tail_refs)
                     || (head_refs.start.loop || !same_scope(def)) && !mergeable(tail_refs, head_refs)
                     || compressor.option("webkit") && is_funarg(def) !== is_funarg(head.definition)
-                    || !safe_to_rename(head_refs, def)
-                    || !safe_to_rename(references[def.id], head.definition)) {
+                    || head.definition.const_redefs
+                    || !all(head_refs, function(sym) {
+                        return sym.scope.find_variable(def.name) === def;
+                    })) {
                     skipped.push(head);
                     continue;
                 }
@@ -6348,12 +6350,6 @@ Compressor.prototype.compress = function(node) {
         function mergeable(head, tail) {
             return must_visit(head.start, head.end) || must_visit(head.start, tail.start);
         }
-
-        function safe_to_rename(refs, def) {
-            return all(refs, function(sym) {
-                return sym.scope.find_variable(def.name) === def;
-            });
-        }
     });
 
     function fill_holes(orig, elements) {

diff --git a/test/compress/let.js b/test/compress/let.js
@@ -270,8 +270,8 @@ merge_vars_3: {
             var b = console;
             console.log(typeof b);
         }
-        var a = 1;
-        console.log(typeof a);
+        var b = 1;
+        console.log(typeof b);
     }
     expect_stdout: [
         "object",