Re: provides "package" 1

[Richard Heck]

On 06/21/2016 06:58 AM, PhilipPirrip wrote:
> I was wondering if there's a special reason why
> provides fontenc 1
> provides inputenc 1
> provides amsmath 1
>
> prevent the corresponding packages from loading, but
>
> provides fontspec 1
> provides listings 1
> provides polyglossia 1
>
> -for example- don't?
>
> Should I report a bug?

Yes, that's a bug. This should work for all LyX-loaded packages.

I think

diff --git a/src/BufferParams.cpp b/src/BufferParams.cpp
index 373eee5..592833a 100644
--- a/src/BufferParams.cpp
+++ b/src/BufferParams.cpp
@@ -1589,7 +1589,8 @@ bool BufferParams::writeLaTeX(otexstream & os,
LaTeXFeatures & features,
                os << from_ascii(ams);
 
        if (useNonTeXFonts) {
-               os << "\\usepackage{fontspec}\n";
+               if (!features.isProvided("fontspec"))
+                       os << "\\usepackage{fontspec}\n";
                if (features.mustProvide("unicode-math")
                    && features.isAvailable("unicode-math"))
                        os << "\\usepackage{unicode-math}\n";
@@ -2115,7 +2115,7 @@ bool BufferParams::writeLaTeX(otexstream & os,
LaTeXFeatures & features,
        }
        if (features.isRequired("bicaption"))
                lyxpreamble += "\\usepackage{bicaption}\n";
-       if (!listings_params.empty() || features.isRequired("listings"))
+       if (!listings_params.empty() || features.mustProvide("listings"))
                lyxpreamble += "\\usepackage{listings}\n";
        if (!listings_params.empty()) {
                lyxpreamble += "\\lstset{";

fixes the case of listings and fontspec. But I'd like to hear from
others, as I'm not expert on this.

I'm not sure how to handle polyglossia.

Richard