[evince] libview: Invalidate union of old and new selection

[Carlos Garcia Campos <carlosgc src gnome org>]

commit 9fd3d7d9182ecd820b699da232930a23e57ca3c7
Author: Jason Crain <jason aquaticape us>
Date:   Mon Jun 24 23:35:27 2013 -0500

    libview: Invalidate union of old and new selection
    
    Instead of using xor, use the union of old_sel and new_sel to find
    what needs redrawing.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=703024

 libview/ev-view.c |   18 +++---------------
 1 files changed, 3 insertions(+), 15 deletions(-)
---
diff --git a/libview/ev-view.c b/libview/ev-view.c
index 3331cc4..4bc12e7 100644
--- a/libview/ev-view.c
+++ b/libview/ev-view.c
@@ -7285,22 +7285,10 @@ merge_selection_region (EvView *view,
                /* Now we figure out what needs redrawing */
                if (old_sel && new_sel) {
                        if (old_sel->covered_region && new_sel->covered_region) {
-                               /* We only want to redraw the areas that have
-                                * changed, so we xor the old and new regions
-                                * and redraw if it's different */
+                               /* Anything that was previously or currently selected may
+                                * have changed */
                                region = cairo_region_copy (old_sel->covered_region);
-#if CAIRO_VERSION >= CAIRO_VERSION_ENCODE(1, 9, 12)
-                               cairo_region_xor (region, new_sel->covered_region);
-#else
-                               cairo_region_t *tbr;
-                               tbr = cairo_region_copy (new_sel->covered_region);
-
-                               /* xor old_sel, new_sel*/
-                               cairo_region_subtract (tbr, region);
-                               cairo_region_subtract (region, new_sel->covered_region);
-                               cairo_region_union (region, tbr);
-                               cairo_region_destroy (tbr);
-#endif
+                               cairo_region_union (region, new_sel->covered_region);
 
                                if (cairo_region_is_empty (region)) {
                                        cairo_region_destroy (region);