respect a 'only' defined in a post-processor

command/build_test.go

@@ -108,7 +108,7 @@ func TestBuildExceptFileCommaFlags(t *testing.T) {
 	}
 
 	args := []string{
-		"-except=chocolate,apple",
+		"-except=chocolate,vanilla",
 		filepath.Join(testFixture("build-only"), "template.json"),
 	}
 
@@ -118,12 +118,12 @@ func TestBuildExceptFileCommaFlags(t *testing.T) {
 		fatalCommand(t, c.Meta)
 	}
 
-	for _, f := range []string{"chocolate.txt", "apple.txt"} {
+	for _, f := range []string{"chocolate.txt", "vanilla.txt", "tomato.txt"} {
 		if fileExists(f) {
 			t.Errorf("Expected NOT to find %s", f)
 		}
 	}
-	for _, f := range []string{"vanilla.txt", "cherry.txt", "pear.txt", "peach.txt"} {
+	for _, f := range []string{"apple.txt", "cherry.txt", "pear.txt", "peach.txt"} {
 		if !fileExists(f) {
 			t.Errorf("Expected to find %s", f)
 		}

packer/core.go

@@ -180,11 +180,13 @@ func (c *Core) Build(n string) (Build, error) {
 	for _, rawPs := range c.Template.PostProcessors {
 		current := make([]coreBuildPostProcessor, 0, len(rawPs))
 		for _, rawP := range rawPs {
-			// If we skip, ignore
+			if rawP.Skip(rawName) {
+				continue
+			}
+			// -except skips post-processor & build
 			foundExcept := false
-			excepts := append(rawP.OnlyExcept.Except, c.except...)
-			for _, except := range excepts {
-				if except == rawName || except == rawP.Name {
+			for _, except := range c.except {
+				if except == rawP.Name {
 					foundExcept = true
 				}
 			}