Decompile crash: panic on empty or whitespace-only CustomOutputName/OutputName

[tagomorisatoshi]

Description

When importing a shortcut that contains an empty or whitespace-only CustomOutputName or OutputName, the decompiler crashes with a panic.

Environment

• Cherri version: v2.1.0
• OS: macOS (arm64)
• Installation: Homebrew

Steps to Reproduce

1. Have a shortcut with an action that has CustomOutputName set to " " (single space)
2. Run cherri --import=shortcut.shortcut

Error Output

panic: runtime error: index out of range [0] with length 0

goroutine 1 [running]:
main.capitalize({0x140001e061d?, 0x0?})
	/Users/brandonjordan/cherri/main.go:244 +0x108
main.sanitizeIdentifier(0x1400003bcb0)
	/Users/brandonjordan/cherri/decompile.go:283 +0x13c
main.mapUUID({0x140001e0621, 0x24}, {0x140001e061d, 0x1})
	/Users/brandonjordan/cherri/decompile.go:273 +0x64
main.mapIdentifiers()
	/Users/brandonjordan/cherri/decompile.go:86 +0x1b4
main.decompile({0x14000194000?, 0x102b47968?, 0x1030c045d?})
	/Users/brandonjordan/cherri/decompile.go:57 +0x31c
main.main()
	/Users/brandonjordan/cherri/main.go:95 +0x8e8

Root Cause Analysis

In main.go:244, the capitalize function assumes the input string is non-empty:

func capitalize(s string) string {
    var char = s[0]  // panics if s is empty
    ...
}

When sanitizeIdentifier processes a whitespace-only string like " ":

1. strings.TrimSpace(" ") returns ""
2. strings.Split("", " ") returns [""]
3. capitalize("") is called and panics

Suggested Fix

Add an empty string check in capitalize:

func capitalize(s string) string {
    if len(s) == 0 {
        return s
    }
    var char = s[0]
    var after, _ = strings.CutPrefix(s, string(char))
    return fmt.Sprintf("%c%s", unicode.ToUpper(rune(char)), after)
}

Or in sanitizeIdentifier:

func sanitizeIdentifier(identifier *string) {
    *identifier = strings.TrimSpace(*identifier)
    if *identifier == "" {
        *identifier = "Unnamed"
        return
    }
    // ... rest of the function
}

Additional Issue

After fixing the empty name issue, another panic occurs in decompAttachmentString:

panic: runtime error: index out of range [17] with length 11

goroutine 1 [running]:
main.decompAttachmentString(...)
	/Users/brandonjordan/cherri/decompile.go:1059 +0x43c

This appears to be related to string index calculations with attachments.