Regression: incorrect line numbers in source maps

[naartjie]

Hi. It looks like ca5f271 broke something, and line numbers from source maps become out of sync.

I don't know C++ to be able to dig deeper, but I can verify that before this, the line numbers seem to be synced up, at least for my use case, and afterwards they are out. I can also submit my files, so we can create a test case for this. Thoughts?

[mgreter]

Would be nice if you could show us your example. Best would be a minimal test case! Thank you!

[naartjie]

Sure, I will put one together. Let me clean up the files I have, and provide as small a test case as possible.

Thanks for looking into this.

[naartjie]

Here she is, I've tried to strip it down as much as possible:

html {
  padding: 0;
}

body {
  color: #333;
  background-color: #999;
}

@mixin input-size($parent) {
  textarea#{$parent},
  select[multiple]#{$parent} {
    height: auto;
  }
}

@include input-size('.input-sm');

I've also uploaded the compiled examples to this repo:

pre-3.0.1 is compiled with libsass f55b2d5, and post-3.0.1 is compiled with head / 5f3558d.

---

Oh dear, so after all of that, I've just noticed that the broken map contains an extra ; before: "mappings": ";6BAAA..., and the one that works doesn't have that. If I remove it the line numbers are reported fine.

In my original use case where I discovered this, I had 2 ;; at the beginning of the mappings element, and 2 corresponding @include input-size's, and I just went back now, and it looks like removing the ; fixes the issue. So I hope this is a relatively easy fix ;-).

[nkgm]

Same problem here. Problem started with node-sass v1.1.0 - it uses libsass @ ca5f271.

[mgreter]

Thank you for taking the time to produce a minimal test case!
It surely helps us to get to the root cause faster; but I cannot promise any ETA!

[naartjie]

@mgreter NP. Thanks for looking into it.

gh-pages finally caught up, and the test cases are viewable in the browser here: broken and working

[mgreter]

Maybe someone could try the fix at https://github.com/mgreter/libsass/tree/fix/source-map-issues?
Unfortunately we have no source-map tests, so I'm not sure if this breaks anything else, but IMO it is more correct than before! Maybe we can land this in the next release if somebody can confirm it works.

[naartjie]

Hi @mgreter. I have tested your fix/source-map-issues branch, and I can confirm this fixes the issue I was having.

Thanks a lot for having a look at this!! Any chance this could make it into the next release? #697

[mgreter]

Your feedback improved that chance by a lot. Thx! Anyone else!?

[naartjie]

Sorry it took a while, I had a busy weekend, back on track now ;-)

[mgreter]

I'm going to close this, since we have merged a possible fix!
Please re-open this only if the problem with leading ; occurs again!

[naartjie]

Awesome, thanks @mgreter 👍