Async: Ensure the future passed by reference to the handler remains valid.

The reference used to become invalid during execution of the handler,
leading to subtle errors (the job just never finished). Unfortunately
I failed to write a test that catches this, as the test always seems
to work anyways....

1 files changed, 7 insertions, 6 deletions

diff --git a/async/src/async.h b/async/src/async.h
index 73eeaa0..a72d058 100644
--- a/async/src/async.h
+++ b/async/src/async.h
@@ -718,14 +718,14 @@ void EachExecutor<PrevOut, Out, In>::run(const ExecutionPtr &execution)
     }
 
     for (auto arg : prevFuture->value()) {
-        Async::Future<Out> future;
-        EachExecutor<PrevOut, Out, In>::mFunc(arg, future);
+        //We have to manually manage the lifetime of these temporary futures
+        Async::Future<Out> *future = new Async::Future<Out>();
+        EachExecutor<PrevOut, Out, In>::mFunc(arg, *future);
         auto fw = new Async::FutureWatcher<Out>();
         mFutureWatchers.append(fw);
         QObject::connect(fw, &Async::FutureWatcher<Out>::futureReady,
-                         [out, fw, this]() {
-                             auto future = fw->future();
-                             assert(future.isFinished());
+                         [out, fw, this, future]() {
+                             assert(fw->future().isFinished());
                              const int index = mFutureWatchers.indexOf(fw);
                              assert(index > -1);
                              mFutureWatchers.removeAt(index);
@@ -734,8 +734,9 @@ void EachExecutor<PrevOut, Out, In>::run(const ExecutionPtr &execution)
                                  out->setFinished();
                              }
                              delete fw;
+                             delete future;
                          });
-        fw->setFuture(future);
+        fw->setFuture(*future);
     }
 }