Bump to Buildah 1.16.0-dev in upstream

Bump Buildah to v1.16.0-dev in the upstream branch
of Podman.  This will allow us to get a number of new
issues into the upstream branch for use.  The version of
Buildah will need to be bumped to v1.16.0 and then
vendored into Podman before we release Podman v2.0

Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>

vendor/github.com/containers/buildah/imagebuildah/executor.go

@@ -251,8 +251,9 @@ func NewExecutor(store storage.Store, options BuildOptions, mainNode *parser.Nod
 
 // startStage creates a new stage executor that will be referenced whenever a
 // COPY or ADD statement uses a --from=NAME flag.
-func (b *Executor) startStage(stage *imagebuilder.Stage, stages imagebuilder.Stages, output string) *StageExecutor {
+func (b *Executor) startStage(ctx context.Context, stage *imagebuilder.Stage, stages imagebuilder.Stages, output string) *StageExecutor {
 	stageExec := &StageExecutor{
+		ctx:             ctx,
 		executor:        b,
 		index:           stage.Position,
 		stages:          stages,
@@ -289,17 +290,24 @@ func (b *Executor) resolveNameToImageRef(output string) (types.ImageReference, e
 	return imageRef, nil
 }
 
-func (b *Executor) waitForStage(ctx context.Context, name string) error {
-	stage := b.stages[name]
-	if stage == nil {
-		return errors.Errorf("unknown stage %q", name)
+// waitForStage waits for an entry to be added to terminatedStage indicating
+// that the specified stage has finished.  If there is no stage defined by that
+// name, then it will return (false, nil).  If there is a stage defined by that
+// name, it will return true along with any error it encounters.
+func (b *Executor) waitForStage(ctx context.Context, name string, stages imagebuilder.Stages) (bool, error) {
+	found := false
+	for _, otherStage := range stages {
+		if otherStage.Name == name || fmt.Sprintf("%d", otherStage.Position) == name {
+			found = true
+			break
+		}
+	}
+	if !found {
+		return false, nil
 	}
 	for {
 		if b.lastError != nil {
-			return b.lastError
-		}
-		if stage.stage == nil {
-			return nil
+			return true, b.lastError
 		}
 
 		b.stagesLock.Lock()
@@ -307,13 +315,13 @@ func (b *Executor) waitForStage(ctx context.Context, name string) error {
 		b.stagesLock.Unlock()
 
 		if terminated {
-			return nil
+			return true, nil
 		}
 
 		b.stagesSemaphore.Release(1)
 		time.Sleep(time.Millisecond * 10)
 		if err := b.stagesSemaphore.Acquire(ctx, 1); err != nil {
-			return errors.Wrapf(err, "error reacquiring job semaphore")
+			return true, errors.Wrapf(err, "error reacquiring job semaphore")
 		}
 	}
 }
@@ -355,7 +363,7 @@ func (b *Executor) buildStage(ctx context.Context, cleanupStages map[int]*StageE
 	}
 
 	b.stagesLock.Lock()
-	stageExecutor := b.startStage(&stage, stages, output)
+	stageExecutor := b.startStage(ctx, &stage, stages, output)
 	b.stagesLock.Unlock()
 
 	// If this a single-layer build, or if it's a multi-layered
@@ -531,19 +539,19 @@ func (b *Executor) Build(ctx context.Context, stages imagebuilder.Stages) (image
 			go func() {
 				defer b.stagesSemaphore.Release(1)
 				defer wg.Done()
-				imageID, ref, err = b.buildStage(ctx, cleanupStages, stages, index)
-				if err != nil {
+				stageID, stageRef, stageErr := b.buildStage(ctx, cleanupStages, stages, index)
+				if stageErr != nil {
 					ch <- Result{
 						Index: index,
-						Error: err,
+						Error: stageErr,
 					}
 					return
 				}
 
 				ch <- Result{
 					Index:   index,
-					ImageID: imageID,
-					Ref:     ref,
+					ImageID: stageID,
+					Ref:     stageRef,
 					Error:   nil,
 				}
 			}()
@@ -559,6 +567,7 @@ func (b *Executor) Build(ctx context.Context, stages imagebuilder.Stages) (image
 
 		b.stagesLock.Lock()
 		b.terminatedStage[stage.Name] = struct{}{}
+		b.terminatedStage[fmt.Sprintf("%d", stage.Position)] = struct{}{}
 		b.stagesLock.Unlock()
 
 		if r.Error != nil {
@@ -569,7 +578,9 @@ func (b *Executor) Build(ctx context.Context, stages imagebuilder.Stages) (image
 		// If this is an intermediate stage, make a note of the ID, so
 		// that we can look it up later.
 		if r.Index < len(stages)-1 && r.ImageID != "" {
+			b.stagesLock.Lock()
 			b.imageMap[stage.Name] = r.ImageID
+			b.stagesLock.Unlock()
 			// We're not populating the cache with intermediate
 			// images, so add this one to the list of images that
 			// we'll remove later.
@@ -579,6 +590,7 @@ func (b *Executor) Build(ctx context.Context, stages imagebuilder.Stages) (image
 		}
 		if r.Index == len(stages)-1 {
 			imageID = r.ImageID
+			ref = r.Ref
 		}
 	}