LibJS+LibWeb: Clear exceptions after call'ing JavaScript functions

Decorated Interpreter::call() with [[nodiscard]] to provoke thinking
about the returned value at each call site. This is definitely not
perfect and we should really start thinking about slimming down the
public-facing LibJS interpreter API.

Fixes #3136.

1 files changed, 4 insertions, 1 deletions

diff --git a/Libraries/LibWeb/DOM/XMLHttpRequest.cpp b/Libraries/LibWeb/DOM/XMLHttpRequest.cpp
index 6dcf43dde7..b75d272701 100644
--- a/Libraries/LibWeb/DOM/XMLHttpRequest.cpp
+++ b/Libraries/LibWeb/DOM/XMLHttpRequest.cpp
@@ -98,7 +98,10 @@ void XMLHttpRequest::dispatch_event(NonnullRefPtr<DOM::Event> event)
             auto* this_value = wrap(global_object, *this);
             JS::MarkedValueList arguments(global_object.heap());
             arguments.append(wrap(global_object, *event));
-            function.interpreter().call(function, this_value, move(arguments));
+            auto& interpreter = function.interpreter();
+            (void)interpreter.call(function, this_value, move(arguments));
+            if (interpreter.exception())
+                interpreter.clear_exception();
         }
     }
 }