gst: API: gst_get_main_executable_path()

This is useful for plugins that need to inspect the
folder of the main executable in order to determine the
set of features they will expose, for example:

https://github.com/centricular/gstreamer-vst3

https://bugzilla.gnome.org/show_bug.cgi?id=788214

docs/gst/gstreamer-sections.txt

@@ -31,6 +31,7 @@ gst_segtrap_set_enabled
 gst_registry_fork_is_enabled
 gst_registry_fork_set_enabled
 gst_update_registry
+gst_get_main_executable_path
 <SUBSECTION Private>
 GST_QUARK
 GstQuarkId

gst/gst.c

@@ -368,6 +368,27 @@ find_executable_path (void)
 }
 #endif
 
+/**
+ * gst_get_main_executable_path:
+ *
+ * This helper is mostly helpful for plugins that need to
+ * inspect the folder of the main executable to determine
+ * their set of features.
+ *
+ * When a plugin is initialized from the gst-plugin-scanner
+ * external process, the returned path will be the same as from the
+ * parent process.
+ *
+ * Returns: (transfer none): The path of the executable that
+ *   initialized GStreamer, or %NULL if it could not be determined.
+ *
+ * Since: 1.14
+ */
+const gchar *
+gst_get_main_executable_path (void)
+{
+  return _gst_executable_path;
+}
 
 /**
  * gst_init_check:

gst/gst.h

@@ -132,6 +132,9 @@ void            gst_registry_fork_set_enabled   (gboolean enabled);
 GST_EXPORT
 gboolean        gst_update_registry             (void);
 
+GST_EXPORT
+const gchar *   gst_get_main_executable_path    (void);
+
 G_END_DECLS
 
 #endif /* __GST_H__ */

win32/common/libgstreamer.def

@@ -691,6 +691,7 @@ EXPORTS
 	gst_int_range_get_type
 	gst_is_caps_features
 	gst_is_initialized
+	gst_get_main_executable_path
 	gst_iterator_copy
 	gst_iterator_filter
 	gst_iterator_find_custom