Hang when displaying yaml with comment at start of line

[tomgoren]

When using bat on YAML files that include comments which start at the beginning of a line, that is, the first character of the line is a #, bat will hang indefinitely, and never finish displaying the file.

Contents of working file via cat:

$ cat works.yml
test: value

still: okay

 # comment with hash character at beginning of line, but with a space first

will: reach here

Contents of working file via bat:

$ bat works.yml
───────┬────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: works.yml
───────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ test: value
   2   │
   3   │ still: okay
   4   │
   5   │  # comment with hash character at beginning of line, but with a space first
   6   │
   7   │ will: reach here
───────┴────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
$

Without the leading space in the comment line

Contents of broken file via cat:

$ cat broken.yml
test: value

still: okay

# comment with hash character at beginning of line

will: not reach here

Contents of working file via bat:

$ bat broken.yml
───────┬────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: broken.yml
───────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ test: value
   2   │
   3   │ still: okay
   4   │

From this point on, it will linger forever and never finish. Even the comment line isn't shown. Something seems to be wrong with the syntax parsing in this case.

It does work with the -A flag enabled:

$ bat -A broken.yml
───────┬────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
       │ File: broken.yml
───────┼────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
   1   │ test:•value␊
   2   │ ␊
   3   │ still:•okay␊
   4   │ ␊
   5   │ #•comment•with•hash•character•at•beginning•of•line␊
   6   │ ␊
   7   │ will:•not•reach•here␊
───────┴────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
$

It is consistently repeatable. Different values of --style do not change the outcome, it hangs every time.

$ bat --version
bat 0.9.0

bat installed via Homebrew on OS X Mojave.

Darwin Kernel Version 18.2.0: Fri Oct  5 19:41:49 PDT 2018; root:xnu-4903.221.2~2/RELEASE_X86_64 x86_64

[keith-hall]

there was a similar issue which was fixed upstream: trishume/syntect#219
I wonder what is happening in this case

[sharkdp]

@tomgoren Thank you for the detailed bug report!

I can not reproduce this.

This looks very much like the bug that I have reported upstream, as @keith-hall mentioned. It only appeared if a syntax set was dumped to disk and reloaded again.

Did you use bat cache --init in the past (with an older version of bat)? Can you try to run

bat cache --clear

to see if the error goes away?

If that is the case, you should be able to run bat cache --init again without any issues.

[tomgoren]

Holy moly @sharkdp - that fixed it! Thanks. Sorry for any confusion.