[LyX/2.2.x] Let "provides [fontspec|listings|subfig] 1" work.

[Richard Heck]

commit 46133b26bebf1795709fd40696084df83e87c9e6
Author: Richard Heck <rgh...@lyx.org>
Date:   Tue Jun 21 10:50:42 2016 -0400

    Let "provides [fontspec|listings|subfig] 1" work.
    
    (cherry picked from commit f46a52d97ff5528445c8d68d70478379f55774d9)
---
 src/BufferParams.cpp |    7 ++++---
 status.22x           |    3 +++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/BufferParams.cpp b/src/BufferParams.cpp
index 9d121cb..6b56037 100644
--- a/src/BufferParams.cpp
+++ b/src/BufferParams.cpp
@@ -1582,7 +1582,8 @@ 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";
@@ -2047,7 +2048,7 @@ bool BufferParams::writeLaTeX(otexstream & os, 
LaTeXFeatures & features,
        // koma's own caption commands are used instead of caption. We
        // use \PassOptionsToPackage here because the user could have
        // already loaded subfig in the preamble.
-       if (features.isRequired("subfig")) {
+       if (features.mustProvide("subfig")) {
                atlyxpreamble += "\\@ifundefined{showcaptionsetup}{}{%\n"
                        " \\PassOptionsToPackage{caption=false}{subfig}}\n"
                        "\\usepackage{subfig}\n";
@@ -2108,7 +2109,7 @@ 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{";
diff --git a/status.22x b/status.22x
index eff4c0f..788f460 100644
--- a/status.22x
+++ b/status.22x
@@ -28,6 +28,9 @@ What's new
 - Changed the display of buttons for collapsed branches. We now display the
   same thing as if the branches were open (bug 10213).
 
+- "Provides <package> 1" now works with fontspec, subfig, and listings (bug
+  10257).
+
 - Added a new module "Title and Preamble Hacks".