Index: trunk/src_plugins/lib_gtk_common/bu_status_line.c
===================================================================
--- trunk/src_plugins/lib_gtk_common/bu_status_line.c	(revision 11792)
+++ trunk/src_plugins/lib_gtk_common/bu_status_line.c	(revision 11793)
@@ -42,13 +42,12 @@
 		gtk_label_set_markup(GTK_LABEL(status_line_label), text ? text : "");
 }
 
-void pcb_gtk_status_line_update(GtkWidget *status_line_label, int compat_horiz)
+static inline void gen_status_long(char *text, size_t text_size, int compat_horiz, const pcb_unit_t *unit)
 {
 	const gchar *flag = conf_core.editor.all_direction_lines
 		? "*" : (conf_core.editor.line_refraction == 0 ? "X" : (conf_core.editor.line_refraction == 1 ? "_/" : "\\_"));
-	char text[1024];
 
-	pcb_snprintf(text, sizeof(text), _(
+	pcb_snprintf(text, text_size, _(
 		"%m+<b>view</b>=%s  "
 		"<b>grid</b>=%$mS  "
 		"<b>line</b>=%mS (%s%s)%s"
@@ -56,7 +55,7 @@
 		"<b>clearance</b>=%mS  "
 		"<b>text</b>=%i%%  "
 		"<b>buffer</b>=#%i"),
-		conf_core.editor.grid_unit->allow, conf_core.editor.show_solder_side ? _("solder") : _("component"),
+		unit->allow, conf_core.editor.show_solder_side ? _("solder") : _("component"),
 		PCB->Grid,
 		conf_core.design.line_thickness, flag, conf_core.editor.rubber_band_mode ? ",R" : "", compat_horiz ? "\n" : "",
 		conf_core.design.via_thickness, conf_core.design.via_drilling_hole, 
@@ -63,7 +62,46 @@
 		conf_core.design.clearance,
 		conf_core.design.text_scale,
 		conf_core.editor.buffer_number + 1);
+}
 
+static inline void gen_status_short(char *text, size_t text_size, int compat_horiz, const pcb_unit_t *unit)
+{
+	pcb_snprintf(text, text_size, _(
+		"%m+"
+		"grid=%$mS  "
+		"line=%mS "
+		"via=%mS (%mS) "
+		"clearance=%mS"),
+		unit->allow,
+		PCB->Grid,
+		conf_core.design.line_thickness,
+		conf_core.design.via_thickness, conf_core.design.via_drilling_hole, 
+		conf_core.design.clearance);
+}
+
+void pcb_gtk_status_line_update(GtkWidget *status_line_label, int compat_horiz)
+{
+	char text[1024];
+	static const pcb_unit_t *unit_mm = NULL, *unit_mil;
+	pcb_unit_t *unit_inv;
+
+	if (status_line_label == NULL)
+		return;
+
+	if (unit_mm == NULL) { /* cache mm and mil units to save on the lookups */
+		unit_mm  = get_unit_struct("mm");
+		unit_mil = get_unit_struct("mil");
+	}
+
+	gen_status_long(text, sizeof(text), compat_horiz, conf_core.editor.grid_unit);
 	pcb_gtk_status_line_set_text(status_line_label, text);
+
+	if (conf_core.editor.grid_unit == unit_mm)
+		unit_inv = unit_mil;
+	else
+		unit_inv = unit_mm;
+
+	gen_status_short(text, sizeof(text), compat_horiz, unit_inv);
+	gtk_widget_set_tooltip_text(GTK_WIDGET(status_line_label), text);
 }