[glade/wjt/escape-parser-errors] GladeProject: escape markup in parser errors

[Will Thompson <wjt src gnome org>]

commit 18373b590ffd4cfa265677be058e77f4e3915d46
Author: Will Thompson <will willthompson co uk>
Date:   Tue Sep 18 14:30:18 2018 +0100

    GladeProject: escape markup in parser errors
    
    If you try to load a non-XML file, such as Glade's own README, the
    parser error contains something like this:
    
        Start tag expected, '<' not found
    
    glade_util_ui_message() treats the supplied message as markup; so the
    literal < in the error message trips it up:
    
        Gtk-WARNING **: Failed to set text 'Error parsing file '/home/wjt/src/gnome/glade/README' on line 1
        Start tag expected, '<' not found
        ' from markup due to error parsing markup: Error on line 2 char 30: Odd character 'f', expected a '=' 
after attribute name 'not' of element '''
    
    To fix this, escape the message before passing it to
    glade_util_ui_message().

 gladeui/glade-project.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
---
diff --git a/gladeui/glade-project.c b/gladeui/glade-project.c
index 1c40c865..6367342a 100644
--- a/gladeui/glade-project.c
+++ b/gladeui/glade-project.c
@@ -2027,7 +2027,9 @@ glade_project_load_internal (GladeProject *project)
 
       if (message)
         {
-          glade_util_ui_message (glade_app_get_window (), GLADE_UI_ERROR, NULL, "%s", message);
+          gchar *escaped = g_markup_escape_text (message, -1);
+          glade_util_ui_message (glade_app_get_window (), GLADE_UI_ERROR, NULL, "%s", escaped);
+          g_free (escaped);
           g_free (message);
         }
       else