diff options
| -rw-r--r-- | lib/compress.js | 17 | ||||
| -rw-r--r-- | test/compress/drop-unused.js | 21 |
2 files changed, 31 insertions, 7 deletions
diff --git a/lib/compress.js b/lib/compress.js index deb55ade..0cc9c518 100644 --- a/lib/compress.js +++ b/lib/compress.js @@ -1801,14 +1801,17 @@ merge(Compressor.prototype, { } return node; } - if (drop_vars && assign_as_unused - && node instanceof AST_Assign - && node.operator == "=" - && node.left instanceof AST_SymbolRef) { - var def = node.left.definition(); - if (!(def.id in in_use_ids) && self.variables.get(def.name) === def) { - return node.right; + if (drop_vars && assign_as_unused) { + var n = node; + while (n instanceof AST_Assign + && n.operator == "=" + && n.left instanceof AST_SymbolRef) { + var def = n.left.definition(); + if (def.id in in_use_ids + || self.variables.get(def.name) !== def) break; + n = n.right; } + if (n !== node) return n; } if (node instanceof AST_For) { descend(node, this); diff --git a/test/compress/drop-unused.js b/test/compress/drop-unused.js index c1ca1b55..4b613181 100644 --- a/test/compress/drop-unused.js +++ b/test/compress/drop-unused.js @@ -679,3 +679,24 @@ const_assign: { } } } + +issue_1539: { + options = { + cascade: true, + sequences: true, + side_effects: true, + unused: true, + } + input: { + function f() { + var a, b; + a = b = 42; + return a; + } + } + expect: { + function f() { + return 42; + } + } +} |