panic when Inspect an element from an open Dialog

[emicklei]

Describe the bug

Version 0.3.7

Using the example from the docs, I open a Dialog and hit Cmd+Shift+I to open the inspector.
Upon selecting an element in the Dialog, the application exits with a panic.

How to reproduce

Example code

func main() {
	b := c.NewBody()
	bt := core.NewButton(b).SetText("Message")
	bt.OnClick(func(e events.Event) {
		core.MessageDialog(bt, "Something happened", "Message")
	})
	b.RunMainWindow()
}

Relevant output

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x2 addr=0x0 pc=0x102657e10]

goroutine 40 [running]:
cogentcore.org/core/core.(*Frame).AsTree(0x14000368460?)
        <autogenerated>:1
cogentcore.org/core/core.(*TreeButton).Init.func1()
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/values.go:116 +0x44
cogentcore.org/core/tree.(*NodeBase).RunUpdaters.func1(...)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/tree/plan.go:115
cogentcore.org/core/base/tiered.(*Tiered[...]).Do(...)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/base/tiered/tiered.go:30
cogentcore.org/core/tree.(*NodeBase).RunUpdaters(0x14004068808)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/tree/plan.go:113 +0x78
cogentcore.org/core/core.(*WidgetBase).UpdateWidget(0x14004068808)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/update.go:25 +0x34
cogentcore.org/core/core.(*WidgetBase).Update.func1({0x1136c85e0, 0x14004068808}, 0x1400b65bc38?)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/update.go:61 +0x28
cogentcore.org/core/core.(*WidgetBase).Update.(*WidgetBase).WidgetWalkDown.func2({0x1136c8590?, 0x14004068808})
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/widget.go:473 +0xb8
cogentcore.org/core/tree.(*NodeBase).WalkDown(0x14003f9e008, 0x1400a55e9e0)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/tree/nodebase.go:502 +0xfc
cogentcore.org/core/core.(*WidgetBase).WidgetWalkDown(...)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/widget.go:471
cogentcore.org/core/core.(*WidgetBase).Update(0x14003f9e008)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/update.go:60 +0xb4
cogentcore.org/core/core.(*Inspector).Init.func4.1.2.2({0x103018160?, 0x14003df9770?})
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/inspector.go:90 +0xec
cogentcore.org/core/events.(*Listeners).Call(0x1400b65bdf0, {0x10310d5a8, 0x14009347880}, {0x1400b65be60, 0x1, 0x1025cb168?})
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/events/listeners.go:61 +0x100
cogentcore.org/core/core.(*WidgetBase).HandleEvent.func1(...)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/widgetevents.go:244
cogentcore.org/core/base/tiered.(*Tiered[...]).Do(...)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/base/tiered/tiered.go:30
cogentcore.org/core/core.(*WidgetBase).HandleEvent(0x14003fa0008, {0x10310d5a8, 0x14009347880})
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/widgetevents.go:243 +0x164
cogentcore.org/core/core.(*WidgetBase).Send(0x14003fa0008, 0x21, {0x0?, 0x14003f93508?, 0x103103760?})
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/widgetevents.go:180 +0x80
cogentcore.org/core/core.(*Tree).sendSelectEvent(0x14003fa5508, {0x0, 0x0, 0x0})
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/tree.go:836 +0x94
cogentcore.org/core/core.(*Tree).SelectEvent(0x14003fa5508, 0x31057b0?)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/tree.go:862 +0x3c
cogentcore.org/core/core.(*Inspector).selectionMonitor(0x14003db5508)
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/inspector.go:232 +0x14c
created by cogentcore.org/core/core.(*Inspector).toggleSelectionMode in goroutine 25
        /Users/emicklei/go/pkg/mod/cogentcore.org/[email protected]/core/inspector.go:192 +0xf4
exit status 2

Platform

macOS

[AnyCPU]

@emicklei it runs ok on master or v0.3.8.

i used following code:

package main

import (
	"cogentcore.org/core/core"
	"cogentcore.org/core/events"
)

func main() {
	b := core.NewBody()
	bt := core.NewButton(b).SetText("Message")
	bt.OnClick(func(e events.Event) {
		core.MessageDialog(bt, "Something happened", "Message")
	})
	b.RunMainWindow()
}

on latest macOS (Intel).

[emicklei]

yes, works with 0.3.8

[kkoreilly]

Yes, this was fixed by #1444, which was merged as part of #1321, included in v0.3.8. Thanks for pointing that out @AnyCPU.