cpp: Add support for gpgme_cancel

* lang/cpp/src/context.cpp, lang/cpp/context.h
(Context::cancelPendingOperationImmediately): New.
* NEWS: Mention added API
--

This allows immediate canceling of running operations, e.g. when a
thread with a long running operation (like SCD DEVINFO --watch) is
going to be terminated (on application shutdown).

GnuPG-bug-id: 5066

NEWS

@@ -22,6 +22,7 @@ Noteworthy changes in version 1.14.1 (unreleased)
  cpp: EngineInfo::Version::operator!=       NEW.
  cpp: StatusConsumer                        NEW.
  cpp: StatusConsumerAssuanTransaction       NEW.
+ cpp: Context::cancelPendingOperationImmediately NEW.
  qt: operator<<(QDebug debug, const GpgME::Error &err) NEW.
 
 

lang/cpp/src/context.cpp

@@ -1343,6 +1343,11 @@ Error Context::cancelPendingOperation()
     return Error(gpgme_cancel_async(d->ctx));
 }
 
+Error Context::cancelPendingOperationImmediately()
+{
+    return Error(gpgme_cancel(d->ctx));
+}
+
 bool Context::poll()
 {
     gpgme_error_t e = GPG_ERR_NO_ERROR;

lang/cpp/src/context.h

@@ -484,6 +484,7 @@ public:
     GpgME::Error wait();
     GpgME::Error lastError() const;
     GpgME::Error cancelPendingOperation();
+    GpgME::Error cancelPendingOperationImmediately();
 
     class Private;
     const Private *impl() const