Image alignment broken when using placholder and crossfade

[davidschreiber]

Describe the bug

When using AsyncImage to display an image using crossfade and a placeholder, the initial image alignment won't work.

To Reproduce
Here is a small demo activity that shows the issue with little effort:

/** package declaration and imports removed for brevity */

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()

        setContent {
            CoilPlaceholderAlignmentBugTheme {
                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->
                    Column(
                        modifier = Modifier.padding(innerPadding)
                    ) {
                        DemoImage(crossfade = true)
                        DemoImage(crossfade = false)
                    }
                }
            }
        }
    }

    @Composable
    private fun DemoImage(crossfade: Boolean) {
        AsyncImage(
            model = ImageRequest.Builder(LocalContext.current)
                .data("https://fastly.picsum.photos/id/1027/512/512.jpg?hmac=kFBJYzp0Y88x_HGjxrDXixHRgspdPuIO0jIswHYahvY")
                .crossfade(crossfade)
                .build(),
            imageLoader = imageLoader,
            contentDescription = null,
            contentScale = ContentScale.Crop,
            // Note: Removing the placeholder image will also work around the alignment bug.
            placeholder = ColorPainter(Color.Red),
            alignment = Alignment.TopCenter,
            modifier = Modifier
                .aspectRatio(16 / 9f)
                .fillMaxSize(),
        )
    }
}

Here is the output. Note that both images actually use the top anchor, but the one with crossfading enabled ignores the anchor:

Version
This was discovered using Version 2.7.0 of Coil for Compose, but is also reproducible using 3.0.4.

[davidschreiber]

Okay, I figured out that if I manually specify to use a CrossfadeTransition with preferExactIntrinsicSize = true, it works - most likely an issue with me using a sizeless painter as placeholder:

@Composable
private fun DemoImage(crossfade: Boolean) {
    AsyncImage(
        model = ImageRequest.Builder(LocalContext.current)
            .data("https://fastly.picsum.photos/id/1027/512/512.jpg?hmac=kFBJYzp0Y88x_HGjxrDXixHRgspdPuIO0jIswHYahvY")
            .transitionFactory(
                if (crossfade) CrossfadeTransition.Factory(
                    durationMillis = 200,
                    preferExactIntrinsicSize = true
                )
                else Transition.Factory.NONE
            )
            .build(),
        imageLoader = imageLoader,
        contentDescription = null,
        contentScale = ContentScale.Crop,
        // Note: Removing the placeholder image will also work around the alignment bug.
        placeholder = ColorPainter(Color.Red),
        alignment = Alignment.TopCenter,
        modifier = Modifier
            .aspectRatio(16 / 9f)
            .fillMaxSize(),
    )
}

Is this intended behavior, or is it indeed considered a bug?