Fixes #4467. Exception backtrace is nil when it should be present.

We need to back off on this optimization in cases where the exception list exists. Statically, we cannot know if StandardError is really a builtin one or it has been overridden. Even beyond that we had no logic ensuring it was even StandardError-based exception so we would kill backtraces that an outer begin/rescue might want to catch and look at the backtrace. Bare rescues and rescue_mods still are fast which was the main motivation for this optimization.
jruby · Feb 10, 2017 · 948554d · 948554d
1 parent e66f638
commit 948554d
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/core/src/main/java/org/jruby/ir/IRBuilder.java b/core/src/main/java/org/jruby/ir/IRBuilder.java
@@ -3493,7 +3493,12 @@ private boolean canBacktraceBeRemoved(RescueNode rescueNode) {
         if (RubyInstanceConfig.FULL_TRACE_ENABLED || !(rescueNode instanceof RescueModNode) &&
                 rescueNode.getElseNode() != null) return false;
 
-        Node body = rescueNode.getRescueNode().getBodyNode();
+        RescueBodyNode rescueClause = rescueNode.getRescueNode();
+
+        if (rescueClause.getOptRescueNode() != null) return false;  // We will not handle multiple rescues
+        if (rescueClause.getExceptionNodes() != null) return false; // We cannot know if these are builtin or not statically.
+
+        Node body = rescueClause.getBodyNode();
 
         // This optimization omits backtrace info for the exception getting rescued so we cannot
         // optimize the exception variable.