fix `collapse_vars` on nested exception (#2955)

fixes #2954

1 files changed, 5 insertions, 4 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 78aee565..2d0a03ae 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -914,7 +914,7 @@ merge(Compressor.prototype, {
 
     function tighten_body(statements, compressor) {
         var scope = compressor.find_parent(AST_Scope);
-        var in_loop = is_in_loop();
+        var in_loop = is_in_node(AST_IterationStatement);
         var CHANGED, max_iter = 10;
         do {
             CHANGED = false;
@@ -937,9 +937,10 @@ merge(Compressor.prototype, {
             }
         } while (CHANGED && max_iter-- > 0);
 
-        function is_in_loop() {
+        function is_in_node(type) {
+            if (compressor.self() instanceof type) return true;
             for (var node, level = 0; node = compressor.parent(level); level++) {
-                if (node instanceof AST_IterationStatement) return true;
+                if (node instanceof type) return true;
                 if (node instanceof AST_Scope) break;
             }
             return false;
@@ -957,7 +958,7 @@ merge(Compressor.prototype, {
             if (scope.uses_eval || scope.uses_with) return statements;
             var args;
             var candidates = [];
-            var in_try = compressor.self() instanceof AST_Try;
+            var in_try = is_in_node(AST_Try);
             var stat_index = statements.length;
             var scanner = new TreeTransformer(function(node, descend) {
                 if (abort) return node;