Issue 1:
Happens on the latest master version (Channel master, v0.5.8-pre.98).

This was tested with an Android emulator (Nexus 5), Android phone (Sony Xperia Z5 Compact) and Android tablet (Huawei Mediapad M3 lite).

The documentation recommends wrapping the contents of an AlertDialog into a ListView:

/// Typically, this is a [ListView] containing the contents of the dialog.
/// Using a [ListView] ensures that the contents can scroll if they are too
/// big to fit on the display.
final Widget content;

I did just that. It works very well in portrait orientation (at least on my phone), no matter how large the content is and if shrinkWrap is enabled or not.

But in landscape mode (both orientations on my tablet), the following errors are thrown (and only a semi-transparent backdrop is visible):

When shrinkWrap: false:

I/flutter (10060): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (10060): The following assertion was thrown during performLayout():
I/flutter (10060): RenderViewport does not support returning intrinsic dimensions.
I/flutter (10060): Calculating the intrinsic dimensions would require instantiating every child of the viewport, which
I/flutter (10060): defeats the point of viewports being lazy.
I/flutter (10060): If you are merely trying to shrink-wrap the viewport in the main axis direction, consider a
I/flutter (10060): RenderShrinkWrappingViewport render object (ShrinkWrappingViewport widget), which achieves that
I/flutter (10060): effect without implementing the intrinsic dimension API.
I/flutter (10060):
I/flutter (10060): When the exception was thrown, this was the stack:
I/flutter (10060): #0 RenderViewportBase.debugThrowIfNotCheckingIntrinsics.<anonymous closure> (package:flutter/src/rendering/viewport.dart:299:9)
...

The error suggests that enabling shrinkWrap would solve the problem.

When shrinkWrap: true:

I/flutter (10721): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (10721): The following assertion was thrown during performLayout():
I/flutter (10721): RenderShrinkWrappingViewport does not support returning intrinsic dimensions.
I/flutter (10721): Calculating the intrinsic dimensions would require instantiating every child of the viewport, which
I/flutter (10721): defeats the point of viewports being lazy.
I/flutter (10721): If you are merely trying to shrink-wrap the viewport in the main axis direction, you should be able
I/flutter (10721): to achieve that effect by just giving the viewport loose constraints, without needing to measure its
I/flutter (10721): intrinsic dimensions.
I/flutter (10721):
I/flutter (10721): When the exception was thrown, this was the stack:
I/flutter (10721): #0 RenderShrinkWrappingViewport.debugThrowIfNotCheckingIntrinsics.<anonymous closure> (package:flutter/src/rendering/viewport.dart:1544:9)
I/flutter (10721): #1 RenderShrinkWrappingViewport.debugThrowIfNotCheckingIntrinsics (package:flutter/src/rendering/viewport.dart:1554:6)
I/flutter (10721): #2 RenderViewportBase.computeMaxIntrinsicWidth (package:flutter/src/rendering/viewport.dart:321:12)
I/flutter (10721): #3 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #4 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #5 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #6 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #7 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.computeMaxIntrinsicWidth (package:flutter/src/rendering/proxy_box.dart:81:20)
I/flutter (10721): #8 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #9 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #10 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #11 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #12 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.computeMaxIntrinsicWidth (package:flutter/src/rendering/proxy_box.dart:81:20)
I/flutter (10721): #13 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #14 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #15 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #16 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #17 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.computeMaxIntrinsicWidth (package:flutter/src/rendering/proxy_box.dart:81:20)
I/flutter (10721): #18 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #19 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #20 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #21 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #22 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.computeMaxIntrinsicWidth (package:flutter/src/rendering/proxy_box.dart:81:20)
I/flutter (10721): #23 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #24 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #25 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #26 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #27 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.computeMaxIntrinsicWidth (package:flutter/src/rendering/proxy_box.dart:81:20)
I/flutter (10721): #28 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #29 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #30 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #31 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #32 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.computeMaxIntrinsicWidth (package:flutter/src/rendering/proxy_box.dart:81:20)
I/flutter (10721): #33 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #34 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #35 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #36 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #37 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.computeMaxIntrinsicWidth (package:flutter/src/rendering/proxy_box.dart:81:20)
I/flutter (10721): #38 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #39 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #40 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #41 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #42 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.computeMaxIntrinsicWidth (package:flutter/src/rendering/proxy_box.dart:81:20)
I/flutter (10721): #43 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #44 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #45 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #46 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #47 RenderPadding.computeMaxIntrinsicWidth (package:flutter/src/rendering/shifted_box.dart:163:20)
I/flutter (10721): #48 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #49 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #50 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #51 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #52 RenderFlex.computeMaxIntrinsicWidth.<anonymous closure> (package:flutter/src/rendering/flex.dart:575:60)
I/flutter (10721): #53 RenderFlex._getIntrinsicSize (package:flutter/src/rendering/flex.dart:552:58)
I/flutter (10721): #54 RenderFlex.computeMaxIntrinsicWidth (package:flutter/src/rendering/flex.dart:572:12)
I/flutter (10721): #55 RenderBox._computeIntrinsicDimension.<anonymous closure> (package:flutter/src/rendering/box.dart:1109:23)
I/flutter (10721): #56 __InternalLinkedHashMap&_HashVMBase&MapMixin&_LinkedHashMapMixin.putIfAbsent (dart:collection/runtime/libcompact_hash.dart:277:23)
I/flutter (10721): #57 RenderBox._computeIntrinsicDimension (package:flutter/src/rendering/box.dart:1107:41)
I/flutter (10721): #58 RenderBox.getMaxIntrinsicWidth (package:flutter/src/rendering/box.dart:1291:12)
I/flutter (10721): #59 RenderIntrinsicWidth.performLayout (package:flutter/src/rendering/proxy_box.dart:622:36)
I/flutter (10721): #60 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #61 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #62 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #63 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #64 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #65 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #66 _RenderCustomClip.performLayout (package:flutter/src/rendering/proxy_box.dart:1147:11)
I/flutter (10721): #67 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #68 RenderConstrainedBox.performLayout (package:flutter/src/rendering/proxy_box.dart:263:13)
I/flutter (10721): #69 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #70 RenderPositionedBox.performLayout (package:flutter/src/rendering/shifted_box.dart:381:13)
I/flutter (10721): #71 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #72 RenderPadding.performLayout (package:flutter/src/rendering/shifted_box.dart:199:11)
I/flutter (10721): #73 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #74 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #75 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #76 RenderPadding.performLayout (package:flutter/src/rendering/shifted_box.dart:199:11)
I/flutter (10721): #77 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #78 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #79 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #80 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #81 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #82 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #83 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #84 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #85 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #86 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #87 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #88 _RenderProxyBox&RenderBox&RenderObjectWithChildMixin&RenderProxyBoxMixin.performLayout (package:flutter/src/rendering/proxy_box.dart:109:13)
I/flutter (10721): #89 RenderOffstage.performLayout (package:flutter/src/rendering/proxy_box.dart:2824:13)
I/flutter (10721): #90 RenderObject.layout (package:flutter/src/rendering/object.dart:1570:7)
I/flutter (10721): #91 RenderStack.performLayout (package:flutter/src/rendering/stack.dart:520:15)
I/flutter (10721): #92 RenderObject._layoutWithoutResize (package:flutter/src/rendering/object.dart:1445:7)
I/flutter (10721): #93 PipelineOwner.flushLayout (package:flutter/src/rendering/object.dart:704:18)
I/flutter (10721): #94 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding.drawFrame (package:flutter/src/rendering/binding.dart:270:19)
I/flutter (10721): #95 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding&WidgetsBinding.drawFrame (package:flutter/src/widgets/binding.dart:627:13)
I/flutter (10721): #96 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding&PaintingBinding&RendererBinding._handlePersistentFrameCallback (package:flutter/src/rendering/binding.dart:208:5)
I/flutter (10721): #97 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._invokeFrameCallback (package:flutter/src/scheduler/binding.dart:990:15)
I/flutter (10721): #98 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding.handleDrawFrame (package:flutter/src/scheduler/binding.dart:930:9)
I/flutter (10721): #99 _WidgetsFlutterBinding&BindingBase&GestureBinding&ServicesBinding&SchedulerBinding._handleDrawFrame (package:flutter/src/scheduler/binding.dart:842:5)
I/flutter (10721): #100 _invoke (dart:ui/hooks.dart:125:13)
I/flutter (10721): #101 _drawFrame (dart:ui/hooks.dart:114:3)
I/flutter (10721):
I/flutter (10721): The following RenderObject was being processed when the exception was fired:
I/flutter (10721): RenderIntrinsicWidth#1b077 relayoutBoundary=up5 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): creator: IntrinsicWidth ← DefaultTextStyle ← AnimatedDefaultTextStyle ←
I/flutter (10721): _InkFeatures-[GlobalKey#02057 ink renderer] ← NotificationListener<LayoutChangedNotification> ←
I/flutter (10721): CustomPaint ← _ShapeBorderPaint ← PhysicalShape ← _MaterialInterior ← Material ← ConstrainedBox ←
I/flutter (10721): Center ← ⋯
I/flutter (10721): parentData: <none> (can use size)
I/flutter (10721): constraints: BoxConstraints(280.0<=w<=512.0, 0.0<=h<=288.0)
I/flutter (10721): size: MISSING
I/flutter (10721): stepWidth: null
I/flutter (10721): stepHeight: null
I/flutter (10721): This RenderObject had the following descendants (showing up to depth 5):
I/flutter (10721): RenderFlex#b6207 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): RenderPadding#44560 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): RenderSemanticsAnnotations#0847a NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): RenderParagraph#4110e NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): RenderPadding#b728b NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): RenderRepaintBoundary#22c8d NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): RenderCustomPaint#f7921 NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): RenderRepaintBoundary#f191e NEEDS-LAYOUT NEEDS-PAINT
I/flutter (10721): ════════════════════════════════════════════════════════════════════════════════════════════════════
I/flutter (10721): Another exception was thrown: RenderBox was not laid out: RenderIntrinsicWidth#1b077 relayoutBoundary=up5 NEEDS-PAINT
I/flutter (10721): Another exception was thrown: RenderBox was not laid out: _RenderInkFeatures#fca13 relayoutBoundary=up4 NEEDS-PAINT
I/flutter (10721): Another exception was thrown: RenderBox was not laid out: RenderCustomPaint#b713d relayoutBoundary=up3 NEEDS-PAINT
I/flutter (10721): Another exception was thrown: RenderBox was not laid out: RenderPhysicalShape#968ac relayoutBoundary=up2 NEEDS-PAINT
I/flutter (10721): Another exception was thrown: 'package:flutter/src/rendering/shifted_box.dart': Failed assertion: line 310 pos 12: 'child.hasSize': is not true.
I/flutter (10721): Another exception was thrown: RenderBox was not laid out: RenderPhysicalShape#968ac relayoutBoundary=up2

How to reproduce

import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Dialog Landscape Error',
home: new DialogTestScreen(),
);
}
}

class DialogTestScreen extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Dialog Landscape Error'),
),
body: Center(
child: Column(
children: <Widget>[
RaisedButton(
child: Text('Open Dialog without shrinkWrap'),
onPressed: () {
showDialog(
context: context,
builder: (BuildContext context) => TestDialog(shrinkWrap: false),
);
},
),
RaisedButton(
child: Text('Open Dialog with shrinkWrap'),
onPressed: () {
showDialog(
context: context,
builder: (BuildContext context) => TestDialog(shrinkWrap: true),
);
},
),
],
)
),
);
}
}

class TestDialog extends StatelessWidget {
const TestDialog({Key key, this.shrinkWrap}) : super(key: key);

final bool shrinkWrap;

@override
Widget build(BuildContext context) {
return AlertDialog(
title: Text('Test Dialog'),
content: ListView(
children: <Widget>[
Text('Child 1'),
Text('Child 2')
],
shrinkWrap: shrinkWrap,
),
);
}
}

Issue 2:
Steps to Reproduce

code :

rect = Rect.fromCircle(center: center, radius: radius);
angle = 160.0 * (-1);
double startAngle = -math.pi / 2;
double sweepAngle = 2 * math.pi * (angle / 360);
print(
'angle === $angle --- $startAngle --- $sweepAngle --- ${rect.toString()} --- $progressPaint');
canvas.drawArc(rect, startAngle, sweepAngle, false, progressPaint);

It doesn't work

2.

canvas.drawArc(rect, startAngle, sweepAngle, true, progressPaint);

It work, Why?

Logs