Wrappable RichText in a Split container causes crash

[matwachich]

Describe the bug:

App crashing (index out of range) when totally shrinking a RichText with a HSplit container

To Reproduce:

Run the provided code, and slide completly to the right

Example code:

package main

import (
	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/app"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/widget"
)

func main() {
	a := app.New()
	w := a.NewWindow("TItle")

	rich := widget.NewRichText()
	rich.Wrapping = fyne.TextWrapWord
	rich.ParseMarkdown("Hello, world!")

	w.SetContent(
		container.NewHSplit(
			widget.NewLabel("Test"),
			rich,
		),
	)

	w.Resize(fyne.NewSize(800, 400))
	w.ShowAndRun()
}

-->

Device (please complete the following information):

• OS: Windows
• Version: 10
• Go version: 1.18.2
• Fyne version: 2.1.4

[andydotxyz]

Can you please provide the crash log, it will be helpful to verify the issue and confirm the fix.

[matwachich]

panic: runtime error: index out of range [-1]

goroutine 19 [running]:
fyne.io/fyne/v2/widget.(*RichText).updateRowBounds.func1({0xc000088300?, 0x2, 0x4?})
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/widget/richtext.go:381 +0xc25
fyne.io/fyne/v2/widget.(*RichText).updateRowBounds(0xc0000c0000)
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/widget/richtext.go:411 +0x103
fyne.io/fyne/v2/widget.(*RichText).Resize(0xc0000c0000, {0x44460000?, 0x42370000?})
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/widget/richtext.go:109 +0x105
fyne.io/fyne/v2/container.(*splitContainerRenderer).Layout(0xc000092120, {0x39c000?, 0xc0?})
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/container/split.go:126 +0x237
fyne.io/fyne/v2/container.(*splitContainerRenderer).Refresh(0xc000092120)
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/container/split.go:155 +0xa5
fyne.io/fyne/v2/widget.(*BaseWidget).Refresh(0x7ff72e33f0fd?)
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/widget/widget.go:138 +0x2e
fyne.io/fyne/v2/container.(*Split).SetOffset(...)
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/container/split.go:79
fyne.io/fyne/v2/container.(*divider).Dragged(0xc0000a8050, 0xc000090078)
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/container/split.go:248 +0x216
fyne.io/fyne/v2/internal/driver/glfw.(*window).mouseMoved.func5()
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/internal/driver/glfw/window.go:732 +0x26
fyne.io/fyne/v2/internal/driver/common.(*Window).RunEventQueue(0xc0000b4000)
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/internal/driver/common/window.go:58 +0x56
created by fyne.io/fyne/v2/internal/driver/glfw.(*gLDriver).createWindow.func1
        C:/Users/Matwachich/Programmation/GoLang/src/Fyne/vendor/fyne.io/fyne/v2/internal/driver/glfw/window.go:1413 +0x156
exit status 2

[andydotxyz]

Thanks, confirmed

[andydotxyz]

I have a working fix, which wraps the word down to letters when there is not room.
But realistically I thought, should we not have the min size to the smallest word in the content?
Technically yes - but what if it's a really long word? I don't know if we should prop the content open...

[andydotxyz]

Fix will be in v2.2.3