Crash parsing invalid file URI

[secsys-go]

Checklist

• I have searched the issue tracker for open issues that relate to the same problem, before opening a new one.
• This issue only relates to a single bug. I will open new issues for any other problems.

Describe the bug

We used the Fuzz engine to modify some Test(TestFromJSON) data, and then the following crash appeared. We hope to get the help of the developer to confirm whether it is a real bug.

How to reproduce

The simplified test code is in Example code

Screenshots

crash log:

panic: runtime error: slice bounds out of range [5:4] [recovered]
        panic: runtime error: slice bounds out of range [5:4]

goroutine 35 [running]:
testing.tRunner.func1.2({0x62e6c0, 0xc0001d43d8})
        /home/zjx/.local/go/src/testing/testing.go:1211 +0x24e
testing.tRunner.func1()
        /home/zjx/.local/go/src/testing/testing.go:1214 +0x218
panic({0x62e6c0, 0xc0001d43d8})
        /home/zjx/.local/go/src/runtime/panic.go:1038 +0x215
fyne.io/fyne/v2/storage/repository.ParseURI({0xc0001b9770, 0x4})
        /home/zjx/workspace/gowork/src/purelib/fyne/storage/repository/parse.go:63 +0x737
fyne.io/fyne/v2/storage.ParseURI(...)
        /home/zjx/workspace/gowork/src/purelib/fyne/storage/uri.go:35
fyne.io/fyne/v2/theme.uriString.resource({0xc0001b9770, 0xc00019a128})
        /home/zjx/workspace/gowork/src/purelib/fyne/theme/json.go:82 +0x1f
fyne.io/fyne/v2/theme.(*jsonTheme).Font(0xc0001b0528, {0x0, 0x0, 0x1, 0x0, 0x0})
        /home/zjx/workspace/gowork/src/purelib/fyne/theme/json.go:146 +0xbb
fyne.io/fyne/v2/theme.FuzzTestFromJSON({0xc00036f600, 0x22, 0x200})
        /home/zjx/workspace/gowork/src/purelib/fyne/theme/json_test.go_TestFromJSON_test.go:74 +0x143

Example code

        var1:="0000"
	var2:=`{"Fonts":{"monospace":"file"}}0000{"Fonts":{"monospace":"file"}}0000{"Fonts":{"monospace":"file"}}0000{"Fonts":{"monospace":"file"}}0000{"Fonts":{"monospace":"file"}}0000{"Fonts":{"monospace":"file"}}0000{"Fonts":{"monospace":"file"}}0000{"F`
	repository.Register(var1, intRepo.NewFileRepository())
	th, err := FromJSON(var2)
	assert.Nil(t, err)
	th.Font(fyne.TextStyle{Monospace: true}).Name()

Fyne version

638ae24

Go compiler version

1.17.8

Operating system

Linux

Operating system version

Linux r920 4.15.0-159-generic #167-Ubuntu

Additional Information

No response

[ChandanChainani]

@secsys-go Please can you attach implementation for FromJSON

[Jacalz]

@secsys-go Please can you attach implementation for FromJSON

What do you mean? This is a about a crash when using the theme test for FromJSON:

fyne/theme/json.go

Line 20 in a834925

func FromJSON(data string) (fyne.Theme, error) {

.

[ChandanChainani]

@Jacalz Thanks, I was working on old branch so was not able to find the file. raised PR with the fix please review

[andydotxyz]

This was resolved