Setting RangeSelector to 100-100 with max value to 1 crashes DWM.

[raphm4044]

Describe the bug

When some bizarre values are set in a RangeSelector, the DWM crashes.

Steps to reproduce

Set a RangeSelector to 100-100, and set the max value to 1.

Expected behavior

I don't really know what to expect else. Prevent the control from rendering?

Screenshots

No response

Code Platform

• UWP
• WinAppSDK / WinUI 3
• Web Assembly (WASM)
• Android
• iOS
• MacOS
• Linux / GTK

Windows Build Number

• Windows 10 1809 (Build 17763)
• Windows 10 1903 (Build 18362)
• Windows 10 1909 (Build 18363)
• Windows 10 2004 (Build 19041)
• Windows 10 20H2 (Build 19042)
• Windows 10 21H1 (Build 19043)
• Windows 10 21H2 (Build 19044)
• Windows 10 22H2 (Build 19045)
• Windows 11 21H2 (Build 22000)
• Other (specify)

Other Windows Build number

Windows 11 Canary (Germanium) 26063

App minimum and target SDK version

• Windows 10, version 1809 (Build 17763)
• Windows 10, version 1903 (Build 18362)
• Windows 10, version 1909 (Build 18363)
• Windows 10, version 2004 (Build 19041)
• Windows 10, version 2104 (Build 20348)
• Windows 11, version 22H2 (Build 22000)
• Other (specify)

Other SDK version

Unknown. I use the WCT Gallery.

Visual Studio Version

2022

Visual Studio Build Number

17.9.1

Device form factor

Desktop

Additional context

I'm using the WCT gallery. Happens on the first example of RangeSelector.

Help us help you

No, I'm unable to contribute a solution.

[sylveon]

Can repro. I'd argue min == max should be an invalid state here (i.e. the control should throw if someone tries to do that)

[Lamparter]

        if (Minimum == Maximum)
        {
-           Maximum += Epsilon;
+           throw new ArgumentException("Maximum and Minimum values cannot be equal.");
        }

[michael-hawker]

@Arlodotexe not sure how we missed triaging this originally, but we definitely should understand why the DWM crashes in this state, and file an underlying issue with the platform to fix, while avoiding that scenario in our control.

As called out in the PR discussion here: #576 (comment)

I believe this should be valid input based on how Slider behaves, it accepts both min/max as equal and just locks the value.

It may not make sense, but in general most XAML controls don't throw exceptions, as those will take down apps at runtime.