[gtk] builder-tool: Don't empty out <mark> elements

[Matthias Clasen <matthiasc src gnome org>]

commit fe822a0a244245a5323b12d710f7072c0b634c07
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Apr 5 03:05:08 2019 +0000

    builder-tool: Don't empty out <mark> elements
    
    We were inadvertedly losing the content of <mark>
    elements. Fix this, by marking (!) them as pcdata
    elements.

 gtk/tools/gtk-builder-tool-simplify.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gtk/tools/gtk-builder-tool-simplify.c b/gtk/tools/gtk-builder-tool-simplify.c
index 9489e4efb0..144f823e6a 100644
--- a/gtk/tools/gtk-builder-tool-simplify.c
+++ b/gtk/tools/gtk-builder-tool-simplify.c
@@ -241,6 +241,7 @@ is_pcdata_element (Element *element)
     "mime-type",
     "col",
     "item",
+    "mark",
     NULL,
   };