Make Env::AppBundle constructor exception safe

When the Env::AppBundle constructor throws an exception
it still needs to run ~AppBundle(), otherwise the JobQueue
isn't properly shut down.  Specifically the  JobQueue
can destruct without waiting on outstanding jobs in the
queue.

This change ensures that if Env::AppBundle constructor
throws, Env::AppBundle::~AppBundle() runs.

This fixes the unit test crash exposed by PR #3047.

src/test/jtx/Env.h

@@ -124,12 +124,13 @@ public:
 private:
     struct AppBundle
     {
-        Application* app;
+        Application* app = nullptr;
         std::unique_ptr<Application> owned;
-        ManualTimeKeeper* timeKeeper;
+        ManualTimeKeeper* timeKeeper = nullptr;
         std::thread thread;
         std::unique_ptr<AbstractClient> client;
 
+        AppBundle() = default;
         AppBundle (beast::unit_test::suite& suite,
             std::unique_ptr<Config> config,
             std::unique_ptr<Logs> logs);

src/test/jtx/Env_test.cpp

@@ -749,6 +749,22 @@ public:
         }
     }
 
+    void testExceptionalShutdown()
+    {
+        except(
+            [this]
+            {
+                jtx::Env env {*this,
+                              jtx::envconfig([](std::unique_ptr<Config> cfg)
+                              {
+                                  (*cfg).deprecatedClearSection("port_rpc");
+                                  return cfg;
+                              })};
+            }
+        );
+        pass();
+    }
+
     void
     run() override
     {
@@ -771,6 +787,7 @@ public:
         testResignSigned();
         testSignAndSubmit();
         testFeatures();
+        testExceptionalShutdown();
     }
 };
 

src/test/jtx/impl/Env.cpp

@@ -59,6 +59,7 @@ namespace jtx {
 Env::AppBundle::AppBundle(beast::unit_test::suite& suite,
     std::unique_ptr<Config> config,
     std::unique_ptr<Logs> logs)
+    : AppBundle()
 {
     using namespace beast::severities;
     // Use kFatal threshold to reduce noise from STObject.
@@ -89,9 +90,13 @@ Env::AppBundle::~AppBundle()
     client.reset();
     // Make sure all jobs finish, otherwise tests
     // might not get the coverage they expect.
-    app->getJobQueue().rendezvous();
-    app->signalStop();
-    thread.join();
+    if (app)
+    {
+        app->getJobQueue().rendezvous();
+        app->signalStop();
+    }
+    if (thread.joinable())
+        thread.join();
 
     // Remove the debugLogSink before the suite goes out of scope.
     setDebugLogSink (nullptr);