SizedBox calculates intrinsic dimensions incorrectly #137546
Description
Let's start with example, you can paste it into https://dartpad.dev
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
void main() {
debugPaintSizeEnabled = true;
runApp(
const MaterialApp(
home: Scaffold(
body: Center(
child: IntrinsicHeight(
child: SizedBox(
width: 100,
child: Column(
children: [
Text(lipsum),
],
),
),
),
),
),
),
);
}
const lipsum =
'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nullam malesuada vulputate efficitur. Curabitur a nulla et nulla bibendum rhoncus. Duis nec porttitor nunc, vitae pharetra sapien. Ut et vulputate velit, eget porttitor nulla. Curabitur maximus dui id nunc ornare lacinia.';The Column has height equal to intrinsic heigth of its child. But it's wrong. The computeMinIntrinsicHeight doesn't take into account the SizedBox's width when it should. It calculates the intrinsic height with the height it receives from the parent. You can see this height by commenting out the width line.
Reproducible both on Flutter stable (3.13.7) and master (3.16.0-11.0.pre.3).
| Expected | Actual | What intrinsic height "sees" as width |
|---|---|---|
The faulty code is in RenderConstrainedBox, so it touches not only SizedBox, but also ConstrainedBox and possibly other widgets. It's both in compute intrinsic height and width methods.
@override
double computeMinIntrinsicHeight(double width) {
if (_additionalConstraints.hasBoundedHeight && _additionalConstraints.hasTightHeight) {
return _additionalConstraints.minHeight;
}
final double height = super.computeMinIntrinsicHeight(width);
assert(height.isFinite);
if (!_additionalConstraints.hasInfiniteHeight) {
return _additionalConstraints.constrainHeight(height);
}
return height;
}