Fix Dropdown issue

src/mappings.h

@@ -17,6 +17,13 @@ namespace gkeymapper {
 MappingSet collect_mappings(const std::vector<KeyRow>& rows);
 void apply_mappings(const MappingSet& set, const std::vector<KeyRow>& rows);
 
+// The same round trip as text (the mappings file format), for rows that have to
+// leave the process: the window that replaces a running instance is given them by
+// it (see src/singleinstance), so edits that were never saved survive a second
+// start as well.
+std::string mappings_text(const std::vector<KeyRow>& rows);
+void apply_mappings_text(const std::string& text, const std::vector<KeyRow>& rows);
+
 // Collects the current widget state and writes it to path.
 bool write_mappings(const std::string& path, const std::vector<KeyRow>& rows);