Stack overflow with exception handling in futures

[drussel]

Currently, exceptions are handle inline (without creating new promises). This can cause a stack overflow when there are long chains of futures. They could instead be passed off to the executor which appears to help if it is an async one (but I guess the problem would still be there in the case of an immediate executor).

diff --git a/ThirdParty/stlab/concurrency/future.hpp b/ThirdParty/stlab/concurrency/future.hpp
index c0ec59397..d92667fd9 100644
--- a/ThirdParty/stlab/concurrency/future.hpp
+++ b/ThirdParty/stlab/concurrency/future.hpp
@@ -288,7 +288,7 @@ struct shared_base<T, enable_if_copyable<T>> : std::enable_shared_from_this<shar
             _ready = true;
         }
         // propagate exception without scheduling
-        for (const auto& e : then) { e.second(); }
+        for (const auto& e : then) { _executor(e.second); }
     }

     template <typename F, typename... Args>
@@ -456,8 +456,7 @@ struct shared_base<void> : std::enable_shared_from_this<shared_base<void>> {
             then = std::move(_then);
             _ready = true;
         }
-        // propagate exception without scheduling
-        for (const auto& e : then) { e.second(); }
+        for (const auto& e : then) { _executor(e.second); }
     }

     auto get_try() -> bool {

[FelixPetriconi]

Take over the fix

[fosterbrereton]

This issue has been fixed in master as of the 1.1 release.