pkgAcqMetaClearSig: Abort transaction when pkgAcquire::Run has been cancelled

Ongoing Run can be cancelled by returning false from ::Pulse(). In this case
the items would still be called pkgAcquire::Item::Finished() as usual, causing
pkgAcqMetaClearSig to commit the incomplete transaction anyway as at that
point it's still Started and has no errors.

Add a pkgAcquire::Item::Cancelled() method and use it in pkgAcqMetaClearSig
to abort the transaction.

Closes: #1078608

1 files changed, 4 insertions, 0 deletions

diff --git a/apt-pkg/acquire.cc b/apt-pkg/acquire.cc
index 95b6391cd..62d477f95 100644
--- a/apt-pkg/acquire.cc
+++ b/apt-pkg/acquire.cc
@@ -794,6 +794,10 @@ stop:
    for (Queue *I = Queues; I != 0; I = I->Next)
       I->Shutdown(false);
 
+   if (WasCancelled)
+      for (ItemIterator I = Items.begin(); I != Items.end(); ++I)
+         (*I)->Cancelled();
+
    // Shut down the items
    for (auto &Item : Items)
       Item->Finished();