[Development] Behavior-changing bugfixes in patch-level releases

[Arno Rehn]

Hi Mitch,

On 12.07.2023 09:52, EXT Mitch Curtis wrote:
>> Context: We have been hit by 
>> https://codereview.qt-project.org/c/qt/qtdeclarative/+/472596
>> (which is even marked as "Important Behavior Change") ending up
>> only in 6.5.1. It was quite the headache figuring out that 6.5.0 ->
>> 6.5.1 has broken part of our ListViews.
> 
> I'm sorry to hear that.
> 
> As the developer who approved the change, I've left my thoughts
> here:
> 
> https://bugreports.qt.io/browse/QTBUG-114166?focusedId=734562&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-734562
>
>  In summary, I believe the official branch policy was followed here.
> 
> I'm not sure if your use case is the same as the snippet in the bug
> report, so it would be useful if you could share it so that we can
> see if there's a legitimate usage that we've broken. That's not to
> say that it's good to introduce regressions, of course, but often
> it's hard to know how users are using APIs and we often only find out
> after the change has been merged, because auto tests can't cover
> every use case for the same reason.

We have a vertical ListView which shows icon-only buttons. The buttons
all have the same width, but depending on the icon size and/or the
style, that width may differ. So we update the contentWidth of the
ListView as soon as the first button is loaded. Something like this:


ListView {
     id: sidebar
     Layout.fillHeight: true
     implicitWidth: contentWidth

     model: // ...

     delegate: IconButton {
         icon.name: // ...
         onImplicitWidthChanged: if (sidebar.contentWidth < 0) {
                                     sidebar.contentWidth = implicitWidth
                                 }
     }
}

Maybe we're doing this wrong; but I didn't find any other viable way to
have a ListView auto-determine the size in the non-scrollable dimension 
based on its content.

-- 
Arno Rehn
Tel +49 89 189 166 0
Fax +49 89 189 166 111
a.rehn at menlosystems.com
www.menlosystems.com

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