Fixes audacity#5969: upload with no audio data

libraries/lib-cloud-audiocom/sync/LocalProjectSnapshot.cpp

@@ -229,6 +229,8 @@ std::shared_ptr<LocalProjectSnapshot> LocalProjectSnapshot::Create(
    auto snapshot = std::make_shared<LocalProjectSnapshot>(
       Tag {}, config, oauthService, extension);
 
+   snapshot->mProjectCloudExtension.OnUploadOperationCreated(snapshot);
+
    snapshot->mProjectBlocksLock = std::make_unique<ProjectBlocksLock>(
       extension, *project,
       [weakSnapshot = std::weak_ptr(snapshot)]
@@ -246,8 +248,6 @@ std::shared_ptr<LocalProjectSnapshot> LocalProjectSnapshot::Create(
          snapshot->mProjectCloudExtension.OnBlocksHashed(*snapshot);
       });
 
-   snapshot->mProjectCloudExtension.OnUploadOperationCreated(snapshot);
-
    return snapshot;
 }
 
@@ -391,11 +391,15 @@ void LocalProjectSnapshot::UpdateProjectSnapshot()
    else
       projectForm.HeadSnapshotId = mProjectCloudExtension.GetSnapshotId();
 
-   projectForm.Hashes.reserve(mProjectBlocksLock->Blocks.size());
-   std::transform(
-      mProjectBlocksLock->Blocks.begin(), mProjectBlocksLock->Blocks.end(),
-      std::back_inserter(projectForm.Hashes),
-      [](const auto& block) { return block.Hash; });
+   // For empty projects, mProjectBlocksLock will be nullptr at this point
+   if (mProjectBlocksLock != nullptr)
+   {
+      projectForm.Hashes.reserve(mProjectBlocksLock->Blocks.size());
+      std::transform(
+         mProjectBlocksLock->Blocks.begin(), mProjectBlocksLock->Blocks.end(),
+         std::back_inserter(projectForm.Hashes),
+         [](const auto& block) { return block.Hash; });
+   }
 
    using namespace audacity::network_manager;
 

libraries/lib-cloud-audiocom/sync/MixdownUploader.cpp

@@ -64,6 +64,21 @@ int CalculateChannels(const TrackList& trackList)
              1 :
              2;
 }
+
+bool HasPlayableTracks(const AudacityProject& project)
+{
+   // Why Any requires non const ref???
+   for (const auto& track :
+        TrackList::Get(const_cast<AudacityProject&>(project))
+           .Any<PlayableTrack>())
+   {
+      if (track->GetStartTime() != track->GetEndTime())
+         return true;
+   }
+
+   return false;
+}
+
 } // namespace
 
 class MixdownUploader::DataExporter final : public ExportProcessorDelegate
@@ -286,8 +301,9 @@ void MixdownUploader::ReportProgress(
          });
    }
 
-   if (state == MixdownState::Succeeded || state == MixdownState::Failed ||
-       state == MixdownState::Cancelled)
+   if (
+      state == MixdownState::Succeeded || state == MixdownState::Failed ||
+      state == MixdownState::Cancelled)
    {
       mFinished.store(true);
       mPromise.set_value({ state, uploadResult });
@@ -296,6 +312,13 @@ void MixdownUploader::ReportProgress(
 
 void MixdownUploader::ExportProject()
 {
+   if (!HasPlayableTracks(mProject))
+   {
+      mFinished.store(true);
+      mPromise.set_value({ MixdownState::Empty });
+      return;
+   }
+
    auto& tracks = TrackList::Get(mProject);
 
    const double t0 = 0.0;

libraries/lib-cloud-audiocom/sync/MixdownUploader.h

@@ -41,6 +41,7 @@ enum class MixdownState
    Succeeded,
    Cancelled,
    Failed,
+   Empty,
 };
 
 struct CLOUD_AUDIOCOM_API MixdownResult final

modules/mod-cloud-audiocom/CloudProjectUtils.cpp

@@ -274,6 +274,7 @@ bool HandleProjectLink(std::string_view uri)
 
    return true;
 }
+
 void UploadMixdownForSnapshot(
    AudacityProject& project, std::shared_ptr<LocalProjectSnapshot> snapshot)
 {