Fix Grid regressions with text in star rows/columns

[hartez]

Description of Change

Fixes for some regressions on 4.8 with Grid layout. Unconstrained star rows affected by star columns now constrain Labels correctly when measuring to allow the text to grow vertically by the correct amount. Star row/column computations no longer include "unmeasured" (i.e. -1) values in size calculations. Star column calculations now account for absolute column widths and partial star column (e.g. "0.7*") when measuring elements where width/height are interdependent (e.g., Labels).

Also adds automated tests for the regressed scenarios.

Issues Resolved

• fixes [Bug] Regression in 4.8.0.1364 : grid row height is not correctly computed, label is truncated #12001
• fixes [Bug] CollectionView items do not resize properly when item template is grid (Regression from 4.7 to 4.8) (Android & iOS) #12175
• fixes [Bug] ListView Cell size measurement problem on 4.8.0 #12462
• fixes [Bug] Grid inside StackLayout does not respect VerticalOptions FillAndExpand on UWP #12363
• fixes Views are clipped when we provide the multi line text (Break from v4.8.0.1143 pre-1) #12292

API Changes

None

Platforms Affected

• Core/XAML (all platforms)

Behavioral/Visual Changes

None

Before/After Screenshots

Not applicable

Testing Procedure

Automated tests

PR Checklist

• Targets the correct branch
• Tests are passing (or failures are unrelated)

[hartez]

The iOS 13 test failures are with the WebView Cookie tests - nothing to do with these changes.

[modplug]

When can we expect a service release with this fix included?

[nZeus]

Can we know when is it going to be released, please?

[MitchBomcanhao]

Can we know when is it going to be released, please?

@nZeus this fix was released one month ago?

[GerriGoorIrex]

I'm still having problems in version 4.8.0.1687 with a Grid in a ListView. If a column is set to auto or star the row height is not calculated correctly. While in version 4.8.0.1560 this is working.

[nZeus]

Can we know when is it going to be released, please?

@nZeus this fix was released one month ago?

Hi @MitchBomcanhao, indeed, it's been released. Release 4.8.0-sr5 corresponds to v4.8.0.1687. This confused me.

We currently cannot upgrade Xamarin.Forms to 4.8.0.1687, because of the bug with Height="X*" (see #12900 and #13034). I'll keep an eye on those issues instead.

[nZeus]

Seems to be fixed in 4.8.0.1821. cc: @GerriGoorIrex