"multiple" import leads maximum call stack

[Xowap]

Hi all,

We have been encountering an issue with imports since the upgrade to v1.7.0

Here is what we do have in our code

@import (reference) "my_bootstrap.less";

@import "bootstrap/less/normalize.less";
@import "bootstrap/less/print.less";
@import "bootstrap/less/utilities.less";
@import "bootstrap/less/grid.less";

We do this to load the various mixins and UI elements as mixins (reference import), but still want to include the grid and some other classes that are useful and do not need to be re-written.

Yet, the upgrade to v1.7.0 has broken this, and the grid (plus other stuff) is not printed anymore. We have been able to pinpoint the apparition of this behavior in ccd8ebb.

Since it looks like that this change is due to the import defaulting to once, we have set the import to multiple. However, this leads to a SyntaxError: Maximum call stack size exceeded.

To be able to reproduce the issue, we have created a set of files

lib.less

@import "mixins";
@import "utils";

mixins.less

.stuff() {
  color: red;
}

root.less

@import (reference) "lib";
@import (multiple) "utils";

utils.less

.stuff {
  .stuff();
}

In this example, the expected output of both lib.less and root.less is

.stuff {
  color: red;
}

However, when processing root.less, the compiler outputs the following error

SyntaxError: Maximum call stack size exceeded in less-import-bug/utils.less on line 2, column 3:
1 .stuff {
2   .stuff();
3 }

I understand that the pointed commit brings consistency, but this breaks the use we currently had of LESS. Can this be fixed if considered as a bug, or can you provide a replacement solution?

Many thanks

[seven-phases-max]

I.e. this is basically the same issue as #1914 (just hidden behind reference + multiple).

Updated: I mean #1915 actually (#1914 is similar but its initial example was never allowed, while #1915 examples worked before 1.6.0).

[Xowap]

@seven-phases-max it indeed looks so

If it is of any help, I can confirm that the exact code of my 4 test files do work flawlessly in beb5273, yet fails in ccd8ebb as stated, which is the commit right after. In other words, even with the multiple keyword it worked, which I hadn't tested until now.

I also had a look at #1915, which seems to appear at 6d3414d, which comes from much earlier.

Yet, the only way I can kind of reproduce #1914 is through my example, which asks the question to know if it happens under the same circumstances, but I'll ask it in the other issue itself.

[seven-phases-max]

Yes, you're right. The offensive commit is 6d3414d - I see the bug there now.
P.S. and thanks for the commits hint, it helped a lot.

[Xowap]

You're welcome :)

So it seems that indeed ccd8ebb did just bring up the bug introduced in 6d3414d

[lukeapage]

Let me know if I shouldn't have closed this!