[libgxps] xpstopdf: make the generated pdf to be 96 dpi

[Ignacio Casal Quinteiro <icq src gnome org>]

commit acd80e1178ba386597961f4669d3e82e8dd1c00c
Author: Ignacio Casal Quinteiro <qignacio amazon com>
Date:   Fri Mar 9 16:25:11 2018 +0100

    xpstopdf: make the generated pdf to be 96 dpi
    
    The page size we get from the xps metadata is in points. When we
    pass this size to cairo we should convert it to 96 dpi since it
    is the dpi we have by default on Windows, without this conversion
    the generated pdf will be using a bigger page size.
    Moreover evince does this conversion as well by itself.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=794248

 tools/gxps-print-converter.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/tools/gxps-print-converter.c b/tools/gxps-print-converter.c
index 140efde..a4f2e13 100644
--- a/tools/gxps-print-converter.c
+++ b/tools/gxps-print-converter.c
@@ -266,13 +266,17 @@ _gxps_converter_print_get_output_size (GXPSPrintConverter *converter,
 
         gxps_page_get_size (page, &page_width, &page_height);
 
+        /* The page width is in points, Windows expects a dpi of 96 while
+         * cairo will handle the dpi in 72. We need to make the conversion
+         * ourselves so we have the right output size
+         */
         if (output_width) {
                 *output_width = converter->paper_width == 0 ?
-                        page_width : converter->paper_width;
+                        page_width * 72.0 / 96.0 : converter->paper_width;
         }
 
         if (output_height) {
                 *output_height = converter->paper_height == 0 ?
-                        page_height : converter->paper_height;
+                        page_height * 72.0 / 96.0 : converter->paper_height;
         }
 }