Syntax file causes crash when block highlight is missing "rules" block

[helpimnotdrowning]

Description of the problem or steps to reproduce

In writing a hyperscript extension to the included syntax/html.yaml file, I added these lines:

    - default:
        start: "<script.*?type=\"text/hyperscript\"?>"
        end: "</script.*?>"
        limit-group: symbol.tag
        rules:
        - include: "_hyperscript"

, along with a file named _hyperscript.yaml right next to it:

filetype: _hyperscript

detect:
    filename: "\\._hs$"

rules:
- comment:
        start: "--"
        end: "$"
        #rules:
        #    - todo: "(TODO|XXX|FIXME)"

On starting Micro, opening any html file (or reloading the syntax in an existing window, ie by Ctrl+S) crashes:

Micro encountered an error: runtime.errorString runtime error: invalid memory address or nil pointer dereference
runtime/panic.go:261 (0x452fd8)
runtime/panic.go:260 (0x452fa6)
github.com/zyedidia/micro/v2/pkg/highlight/parser.go:276 (0x85c4e3)
github.com/zyedidia/micro/v2/pkg/highlight/parser.go:266 (0x85bffb)
github.com/zyedidia/micro/v2/pkg/highlight/parser.go:252 (0x8670d7)
github.com/zyedidia/micro/v2/internal/buffer/buffer.go:807 (0x8670b4)
github.com/zyedidia/micro/v2/internal/buffer/buffer.go:392 (0x864485)
github.com/zyedidia/micro/v2/internal/buffer/buffer.go:261 (0x862fc5)
github.com/zyedidia/micro/v2/cmd/micro/micro.go:203 (0x8f3e76)
github.com/zyedidia/micro/v2/cmd/micro/micro.go:331 (0x8f4793)
runtime/internal/atomic/types.go:194 (0x43e99b)
runtime/asm_amd64.s:1650 (0x46fd01)

Uncommenting the "rules" section stops Micro from crashing.

Micro should load this perfectly fine, despite just being a verbose version of --.*$, or should properly complain of a malformed file.

Specifications

• Ubuntu 20.04.6 LTS
  • micro: 2.0.13/68d88b57 via snap
  • term: SSH --> Debian
• Debian 12.7 / KDE 5
  • micro: 2.0.11/<no hash in output> via apt/bookworm
  • term: Konsole/pwsh

[Andriamanitra]

This should be fixed on master (#3458), although there has not been a release yet since. You may build micro from source or download the nightly release to get the fix.

[JoeKar]

More precisely it was fixed with #3213, which is included in v2.0.14.
Afterwards micro doesn't crash, but you will face the situation #3458 addresses.