dap: next and out now respect breakpoints

If a breakpoint occurs before the step pointed to by next or out, dap
will now stop there instead of the desired location.

This also updates the loop to always set the breakpoints rather than
only when continue is chosen.

Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>

dap/thread.go

@@ -94,9 +94,7 @@ func (t *thread) Evaluate(ctx Context, c gateway.Client, headRef gateway.Referen
 			return err
 		}
 
-		if action == stepContinue {
+		t.setBreakpoints(ctx)
-			t.setBreakpoints(ctx)
-		}
 		k, next, refs, err = t.seekNext(ctx, next, action)
 	}
 	return nil
@@ -464,13 +462,13 @@ func (t *thread) seekNext(ctx Context, from *step, action stepType) (string, *st
 	var target *step
 	switch action {
 	case stepNext:
-		target = from.next
+		target = t.continueDigest(from, from.next)
 	case stepIn:
 		target = from.in
 	case stepOut:
-		target = from.out
+		target = t.continueDigest(from, from.out)
 	case stepContinue:
-		target = t.continueDigest(from)
+		target = t.continueDigest(from, nil)
 	}
 	return t.seek(ctx, target)
 }
@@ -497,8 +495,8 @@ func (t *thread) seek(ctx Context, target *step) (k string, result *step, mounts
 	return k, result, refs, nil
 }
 
-func (t *thread) continueDigest(from *step) *step {
+func (t *thread) continueDigest(from, until *step) *step {
-	if len(t.bps) == 0 {
+	if len(t.bps) == 0 && until == nil {
 		return nil
 	}
 
@@ -513,13 +511,13 @@ func (t *thread) continueDigest(from *step) *step {
 
 	next := func(s *step) *step {
 		cur := s.in
-		for cur != nil {
+		for cur != nil && cur != until {
 			if isBreakpoint(cur.dgst) {
 				return cur
 			}
 			cur = cur.in
 		}
-		return nil
+		return until
 	}
 	return next(from)
 }