aborts(AST_If) returns the `if` node

Previously it returned the abort node from the alternative branch.  This is
not much use as it can be different from the one in the body
branch (i.e. return vs. throw) and can trick us into issues like #591.

Fix #591

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/compress.js b/lib/compress.js
index 345d8ad6..83c3e6d0 100644
--- a/lib/compress.js
+++ b/lib/compress.js
@@ -950,7 +950,7 @@ merge(Compressor.prototype, {
         def(AST_BlockStatement, block_aborts);
         def(AST_SwitchBranch, block_aborts);
         def(AST_If, function(){
-            return this.alternative && aborts(this.body) && aborts(this.alternative);
+            return this.alternative && aborts(this.body) && aborts(this.alternative) && this;
         });
     })(function(node, func){
         node.DEFMETHOD("aborts", func);