Comment 62 for bug 998156

Here's confirmation obtained using gdb with evince:

Breakpoint 5, add_cups_options (key=0x7faa10a346b0 "cups-PageSize", value=0x7faa11235a20 "Custom.595.28x841.89",
    user_data=0x7faa11041090) at /build/buildd/gtk+3.0-3.4.2/./modules/printbackends/cups/gtkprintbackendcups.c:521
521 in /build/buildd/gtk+3.0-3.4.2/./modules/printbackends/cups/gtkprintbackendcups.c
...
Breakpoint 6, add_cups_options (key=0x7faa10a346b5 "PageSize", value=<optimized out>, user_data=<optimized out>)
    at /build/buildd/gtk+3.0-3.4.2/./modules/printbackends/cups/gtkprintbackendcups.c:568
568 new_value = g_strdup_printf ("Custom.%s", value);
(gdb) print new_value
$2 = (gchar *) 0x0
(gdb) n
568 new_value = g_strdup_printf ("Custom.%s", value);
(gdb) n
569 gtk_cups_request_encode_option (request, key, new_value);
(gdb) print new_value
$3 = (gchar *) 0x7faa10914000 "Custom.Custom.595.28x841.89"