fix corner case in `collapse_vars` (#3501)

1 files changed, 9 insertions, 39 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 0888c107..8ef94e43 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -1465,50 +1465,20 @@ merge(Compressor.prototype, {
                 hit_stack.pop();
             }
 
-            function find_stop(node, level, write_only) {
+            function find_stop(node, level) {
                 var parent = scanner.parent(level);
-                if (parent instanceof AST_Assign) {
-                    if (write_only
-                        && !(parent.left instanceof AST_PropAccess
-                            || parent.left.name in lvalues)) {
-                        return find_stop(parent, level + 1, write_only);
-                    }
-                    return node;
-                }
-                if (parent instanceof AST_Binary) {
-                    if (write_only && (!lazy_op[parent.operator] || parent.left === node)) {
-                        return find_stop(parent, level + 1, write_only);
-                    }
-                    return node;
-                }
+                if (parent instanceof AST_Assign) return node;
+                if (parent instanceof AST_Binary) return node;
                 if (parent instanceof AST_Call) return node;
                 if (parent instanceof AST_Case) return node;
-                if (parent instanceof AST_Conditional) {
-                    if (write_only && parent.condition === node) {
-                        return find_stop(parent, level + 1, write_only);
-                    }
-                    return node;
-                }
-                if (parent instanceof AST_Definitions) {
-                    return find_stop(parent, level + 1, true);
-                }
-                if (parent instanceof AST_Exit) {
-                    return write_only ? find_stop(parent, level + 1, write_only) : node;
-                }
-                if (parent instanceof AST_If) {
-                    if (write_only && parent.condition === node) {
-                        return find_stop(parent, level + 1, write_only);
-                    }
-                    return node;
-                }
+                if (parent instanceof AST_Conditional) return node;
+                if (parent instanceof AST_Definitions) return find_stop(parent, level + 1);
+                if (parent instanceof AST_Exit) return node;
+                if (parent instanceof AST_If) return node;
                 if (parent instanceof AST_IterationStatement) return node;
                 if (parent instanceof AST_PropAccess) return node;
-                if (parent instanceof AST_Sequence) {
-                    return find_stop(parent, level + 1, parent.tail_node() !== node);
-                }
-                if (parent instanceof AST_SimpleStatement) {
-                    return find_stop(parent, level + 1, true);
-                }
+                if (parent instanceof AST_Sequence) return find_stop(parent, level + 1);
+                if (parent instanceof AST_SimpleStatement) return find_stop(parent, level + 1);
                 if (parent instanceof AST_Switch) return node;
                 if (parent instanceof AST_Unary) return node;
                 if (parent instanceof AST_VarDef) return node;