fix corner case in merge_vars (#4136)

fixes #4135
2020-09-20 16:54:14 +01:00
parent 90410f9fc3
commit 8fa470c17c
2 changed files with 42 additions and 2 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -4485,9 +4485,12 @@ merge(Compressor.prototype, {
            var head = first.pop();
            var def = head.definition;
            if (!(def.id in prev)) continue;
-            var head_refs = references[def.id];
-            if (!head_refs) continue;
+            if (!references[def.id]) continue;
+            var head_refs = {
+                start: references[def.id].start,
+            };
            while (def.id in merged) def = merged[def.id];
+            head_refs.end = references[def.id].end;
            var skipped = [];
            do {
                var tail = last.pop();