+ string const local_lp = bufferParams().lang_package;
+
+ // Locally, custom is just stored as a string
+ // in bufferParams().lang_package.
+ if (local_lp != "auto"
+ && local_lp != "babel"
+ && local_lp != "default"
+ && local_lp != "none")
+ return LANG_PACK_CUSTOM;
+
+ if (local_lp == "none")
+ return LANG_PACK_NONE;
+
+ /* If "auto" is selected, we load polyglossia if required,
+ * else we select babel.
+ * If babel is selected (either directly or via the "auto"
+ * mechanism), we really do only require it if we have
+ * a language that needs it.
+ */
+ bool const polyglossia_required =
+ isRequired("polyglossia")
+ && isAvailable("polyglossia")
+ && !isProvided("babel")
+ && this->hasOnlyPolyglossiaLanguages();
+ bool const babel_required =
+ !bufferParams().language->babel().empty()
+ || !this->getBabelLanguages().empty();
+
+ if (local_lp == "auto") {
+ // polyglossia requirement has priority over babel
+ if (polyglossia_required)
+ return LANG_PACK_POLYGLOSSIA;
+ else if (babel_required)
+ return LANG_PACK_BABEL;
+ }
+
+ if (local_lp == "babel") {
+ if (babel_required)
+ return LANG_PACK_BABEL;
+ }
+
+ if (local_lp == "default") {
+ switch (lyxrc.language_package_selection) {
+ case LyXRC::LP_AUTO:
+ // polyglossia requirement has priority over babel
+ if (polyglossia_required)
+ return LANG_PACK_POLYGLOSSIA;
+ else if (babel_required)
+ return LANG_PACK_BABEL;
+ break;
+ case LyXRC::LP_BABEL:
+ if (babel_required)
+ return LANG_PACK_BABEL;
+ break;
+ case LyXRC::LP_CUSTOM:
+ return LANG_PACK_CUSTOM;
+ case LyXRC::LP_NONE:
+ return LANG_PACK_NONE;
+ }
+ }
+
+ return LANG_PACK_NONE;