[fix] Ensure all Throwables occurring during exception metadata capture are handled

While this shouldn't happen, currently if it does, the root exception is lost, which can be catastrophic for debugging.

Author: chadlwilson

src/main/java/org/jruby/rack/DefaultRackApplicationFactory.java

@@ -439,7 +439,7 @@ private void captureMessage(final RaiseException re) {
                 rubyException.callMethod(context, "capture");
                 rubyException.callMethod(context, "store");
             }
-            catch (Exception e) {
+            catch (Throwable e) {
                 rackContext.log(INFO, "failed to capture exception message", e);
                 // won't be able to capture anything
             }

src/spec/ruby/rack/application_spec.rb

@@ -476,6 +476,40 @@ def reset_config
         expect(e.message).to eql 'something went wrong'
       end
     end
+
+    it "swallows and logs errors during exception detail capturing" do
+      expect(@rack_config).to receive(:getRackup).and_return("raise 'something went wrong'")
+      expect_any_instance_of(Exception).to receive(:capture).and_raise java.lang.NoClassDefFoundError.new("missing class during exception capture")
+
+      app_factory = mocked_runtime_application_factory
+      app_factory.init @rack_context
+      app_object = app_factory.newApplication
+
+      raise_info_logged = 0
+      raise_error_logged = 0
+      allow(@rack_context).to receive(:log) do |level, msg, e|
+        if level.to_s == 'INFO'
+          expect(msg).to eql 'failed to capture exception message'
+          expect(e).to be_a java.lang.NoClassDefFoundError
+          raise_info_logged += 1
+        elsif level.to_s == 'ERROR'
+          expect(msg).to eql 'unable to initialize application'
+          expect(e).to be_a org.jruby.exceptions.RaiseException
+          raise_error_logged += 1
+        else
+          true
+        end
+      end
+
+      begin
+        app_object.init
+        fail "expected to raise"
+      rescue => e
+        expect(e.message).to eql 'something went wrong'
+      end
+
+      expect(raise_info_logged).to eql 1 # logs info message for exception capture
+    end
   end
 
   describe "getApplication" do