on error reset handlers in FastRTry

com.oracle.truffle.r.nodes.builtin/src/com/oracle/truffle/r/nodes/builtin/fastr/FastRTry.java

@@ -30,6 +30,8 @@ import com.oracle.truffle.api.dsl.Specialization;
 import com.oracle.truffle.api.frame.VirtualFrame;
 import com.oracle.truffle.r.nodes.builtin.RBuiltinNode;
 import com.oracle.truffle.r.nodes.function.call.RExplicitCallNode;
+import com.oracle.truffle.r.runtime.RErrorHandling;
+import com.oracle.truffle.r.runtime.RInternalError;
 import com.oracle.truffle.r.runtime.RRuntime;
 import com.oracle.truffle.r.runtime.builtins.RBuiltin;
 import com.oracle.truffle.r.runtime.data.RArgsValuesAndNames;
@@ -53,6 +55,9 @@ public abstract class FastRTry extends RBuiltinNode.Arg1 {
         try {
             call.execute(frame, func, RArgsValuesAndNames.EMPTY);
         } catch (Throwable ex) {
+            // try to recover from a possibly incosistent state when running tests:
+            // some handlers might still be lying around and interfere with subsequent calls
+            RErrorHandling.resetStacks();
             return formatError(ex);
         }
         return RRuntime.LOGICAL_TRUE;