enhance unused (#3800)

2020-04-18 17:10:24 +01:00
parent 2a508c6e5f
commit f110601fb4
2 changed files with 33 additions and 3 deletions
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -4200,8 +4200,15 @@ merge(Compressor.prototype, {
                    } else if (sym.orig[0] instanceof AST_SymbolCatch) {
                        var value = def.value && def.value.drop_side_effect_free(compressor);
                        if (value) side_effects.push(value);
-                        def.value = null;
-                        head.push(def);
+                        var var_defs = var_defs_by_id.get(sym.id);
+                        if (var_defs.length > 1) {
+                            AST_Node.warn("Dropping duplicated declaration of variable {name} [{file}:{line},{col}]", template(def.name));
+                            remove(var_defs, def);
+                            sym.eliminated++;
+                        } else {
+                            def.value = null;
+                            head.push(def);
+                        }
                    } else {
                        var value = def.value && !def.value.single_use && def.value.drop_side_effect_free(compressor);
                        if (value) {