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

3 files changed, 18 insertions, 0 deletions

diff --git a/apt-pkg/acquire-item.cc b/apt-pkg/acquire-item.cc
index ca649a4b8..458868bec 100644
--- a/apt-pkg/acquire-item.cc
+++ b/apt-pkg/acquire-item.cc
@@ -870,6 +870,10 @@ std::string pkgAcquire::Item::ShortDesc() const				/*{{{*/
    return DescURI();
 }
 									/*}}}*/
+void pkgAcquire::Item::Cancelled()					/*{{{*/
+{
+}
+									/*}}}*/
 void pkgAcquire::Item::Finished()					/*{{{*/
 {
 }
@@ -2006,6 +2010,12 @@ string pkgAcqMetaClearSig::Custom600Headers() const
    return Header;
 }
 									/*}}}*/
+void pkgAcqMetaClearSig::Cancelled()					/*{{{*/
+{
+   if (TransactionManager->State == TransactionStarted)
+      TransactionManager->AbortTransaction();
+}
+									/*}}}*/
 void pkgAcqMetaClearSig::Finished()					/*{{{*/
 {
    if(_config->FindB("Debug::Acquire::Transaction", false) == true)
diff --git a/apt-pkg/acquire-item.h b/apt-pkg/acquire-item.h
index 5861d48be..1182e415e 100644
--- a/apt-pkg/acquire-item.h
+++ b/apt-pkg/acquire-item.h
@@ -253,6 +253,9 @@ class APT_PUBLIC pkgAcquire::Item : public WeakPointable				/*{{{*/
     */
    virtual std::string ShortDesc() const;
 
+   /** \brief Invoked by the worker when the download is cancelled before completion. */
+   virtual void Cancelled();
+
    /** \brief Invoked by the worker when the download is completely done. */
    virtual void Finished();
 
@@ -575,6 +578,7 @@ class APT_HIDDEN pkgAcqMetaClearSig final : public pkgAcqMetaIndex
    bool VerifyDone(std::string const &Message, pkgAcquire::MethodConfig const *Cnf) override;
    void Done(std::string const &Message, HashStringList const &Hashes,
 		     pkgAcquire::MethodConfig const *Cnf) override;
+   void Cancelled() override;
    void Finished() override;
 
    /** \brief Starts downloading the individual index files.
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();