Merge #18551: Do not clear validationinterface entries being executed

2276339a176f83ffe8ceefb3e41ecca8601aa13b Add test for UnregisterAllValidationInterfaces bug (Russell Yanofsky)
3c61abbbc847d725f30d169278d84655571407c1 Do not clear validationinterface entries being executed (Pieter Wuille)

Pull request description:

  The previous code for MainSignalsInstance::Clear would decrement the reference
  count of every interface, including ones that were already Unregister()ed but
  still being executed.

  This fixes the issue pointed out here: https://github.com/bitcoin/bitcoin/pull/18524/files#r404395685 . It's not currently observable.

ACKs for top commit:
  jonasschnelli:
    utACK 2276339a176f83ffe8ceefb3e41ecca8601aa13b - reviewed code and test (thanks @ryanofsky for adding the test).
  MarcoFalke:
    ACK 2276339a176f83ffe8ceefb3e41ecca8601aa13b 🎎
  ryanofsky:
    Code review ACK 2276339a176f83ffe8ceefb3e41ecca8601aa13b. No change to bugfix, just rebased and new test commit added since last review

Tree-SHA512: c1d68e7c681a45c6cadc84e407c2266bcb4b12d34264e1232a61c4eadb74b551231c5a3b1d041de39f507aef4dfa7d4589b8bfe1833f069c739c6270d2a05dbe

1 files changed, 2 insertions, 2 deletions

diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index c06647cb0d..11000774c0 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -67,8 +67,8 @@ public:
     void Clear()
     {
         LOCK(m_mutex);
-        for (auto it = m_list.begin(); it != m_list.end();) {
-            it = --it->count ? std::next(it) : m_list.erase(it);
+        for (const auto& entry : m_map) {
+            if (!--entry.second->count) m_list.erase(entry.second);
         }
         m_map.clear();
     }