IssueTracker

ConstraintLayout version: 2.0.0-alpha4 and above

The height of a child view with 0dp height and top and bottom constrained to its parent within a nested constraint layout seems to be measured incorrectly when the constraint layout's parent layout also contains another nested constraint layout of wrap_content height.

With the layout xml below, I expected the blue view to fill its parent and thus to see no red displayed.
This works as expected up to 2.0.0-alpha3 but on alpha 4 and above, the blue view is smaller than it's parent. (See attached screenshots of this in these versions)

This seems to be fixed if the nestedView height is fixed rather than wrap_content or if app:layout_constrainedHeight="true" is added to the TextView.

Layout xml:
<androidx.constraintlayout.widget.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white">

    <androidx.constraintlayout.widget.ConstraintLayout
            android:id="@+id/nestedView"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent">
        <TextView
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                android:text="Test"/>
    </androidx.constraintlayout.widget.ConstraintLayout>

    <androidx.constraintlayout.widget.ConstraintLayout
            android:layout_width="0dp"
            android:layout_height="0dp"
            android:background="#FF0000"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toBottomOf="@id/nestedView"
            app:layout_constraintBottom_toBottomOf="parent">
        <View
                android:id="@+id/blueView"
                android:layout_width="0dp"
                android:layout_height="0dp"
                android:background="#0000FF"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintBottom_toBottomOf="parent"/>
    </androidx.constraintlayout.widget.ConstraintLayout>

</androidx.constraintlayout.widget.ConstraintLayout>