libsass 3.4: file context fails on missing input path, event though it is provided in constructor

[gauteh]

Using file context with libsass based on example fails on libsass 3.4

Hi,

I am using libsass based on the example provided for the file context here. However, I've had multiple reports of breakage (astroidmail/astroid#248, astroidmail/astroid#244) with libsass 3.4.0 (default on Debian and Arch Linux), getting the error:

Internal Error: File context has no input path

I am loading sass in this way (https://github.com/astroidmail/astroid/blob/master/src/modes/thread_view/theme.cc#L96):

    const char * scsspath = "path/to/file.scss";

    struct Sass_File_Context* file_ctx = sass_make_file_context(scsspath);
    struct Sass_Options* options = sass_file_context_get_options(file_ctx);
    struct Sass_Context* context = sass_file_context_get_context(file_ctx);
    sass_option_set_precision(options, 1);
    sass_option_set_source_comments(options, true);

    sass_file_context_set_options(file_ctx, options);

    int status = sass_compile_file_context (file_ctx);

    if (status != 0) {
      const char * err = sass_context_get_error_message (context);
      ustring erru (err);
      LOG (error) << "theme: error processing: " << erru;

      throw runtime_error (
          ustring::compose ("theme: could not process scss: %1", erru).c_str ());
    }

    const char * output = sass_context_get_output_string(context);
    ustring output_str(output);
    sass_delete_file_context (file_ctx);

    return output_str;

version info:

libsass         3.4.0   (Sass Compiler) [C/C++]

[gauteh]

From looking at git blame the culprit might be 6a5444b, if I remove the call to sass_file_context_set_options the error is lost. I cannot inspect the structs more in depth using gdb at this point since I do not have access to the complete type in gdb.

Adding a sass_option_set_input_path (options, scsspath); makes no difference.

[mgreter]

@gauteh the commit you mention (6a5444b) is not part of libsass 3.4.0? So I'm confused if your report is against master or libsass 3.4.0 (as you stated in your first post)? Also does your example above exhibit the problem or is that just for illustration? Thanks!

[gauteh]

@mgreter Ah - sorry, I did not notice that. The problem is still with libsass 3.4.0. The example exhibits the problem, If I change it to (astroidmail/astroid@b44b9fc):

    struct Sass_File_Context* file_ctx = sass_make_file_context(scsspath);
    struct Sass_Context* context = sass_file_context_get_context(file_ctx);
    sass_option_set_precision((Sass_Options*) file_ctx, 1);
    sass_option_set_source_comments((Sass_Options*) file_ctx, true);

    int status = sass_compile_file_context (file_ctx);

    if (status != 0) {
      const char * err = sass_context_get_error_message (context);
      ustring erru (err);
      LOG (error) << "theme: error processing: " << erru;

      throw runtime_error (
          ustring::compose ("theme: could not process scss: %1", erru).c_str ());
    }

    const char * output = sass_context_get_output_string(context);
    ustring output_str(output);
    sass_delete_file_context (file_ctx);

    return output_str;
  }

it works.

(on a side note: should I free output here? or is it freed by delete_file_context?)

[mgreter]

OK, I was able to verify the issue on linux. Could not reproduce on windows with mingw64 and msys2.

[mgreter]

Can you try out the fix in #2259 ?

Btw. your code can also be fixed to work with current version:

    struct Sass_File_Context* file_ctx = sass_make_file_context(scsspath);
    struct Sass_Context* context = sass_file_context_get_context(file_ctx);
    struct Sass_Options* options = sass_file_context_get_options(file_ctx);
    sass_option_set_precision(options, 1);
    sass_option_set_source_comments(options, true);

-    sass_file_context_set_options(file_ctx, options);

    int status = sass_compile_file_context (file_ctx);

No need to set options again. They are infact the same object. You mostly just need that function if you create options via sass_make_options (which can be usefull if you want to set it up before file or data contexts). If you look at sass_file_context_get_options you'll find it only does return (Sass_Options*) this.

[gauteh]

Hi @mgreter, thanks - your proposed fix works fine (and should be portable if you decide to change the class structure later on). I do not have libsass set up in a development environment at the moment, so I won't have the time to test #2259 now unfortunately. It does look like it would fix the issue though.

[mgreter]

Closing as resolved

[gauteh]

Thanks 😊 ons. 21. des. 2016 kl. 01.10 skrev Marcel Greter <notifications@github.com>:

…

Closing as resolved — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#2257 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AADd-7E5sivtMGP7bTl119Ti0qetcFr5ks5rKG5ygaJpZM4LRhQL> .