Fix opacity of rasterized filters in PDF export

Opacity was applied thrice:
1. when rendering the filter to a pixbuf
   (i.e. transparency was baked into the bitmap)
2. when rendering this pixbuf onto a cairo surface
3. when actually rendering the (now doubly opaque) item

Avoid 1. and 2. and only apply opacity once.

Fixed bug:
  - https://bugs.launchpad.net/inkscape/+bug/381677

2 files changed, 5 insertions, 0 deletions

diff --git a/src/extension/internal/cairo-renderer.cpp b/src/extension/internal/cairo-renderer.cpp
index b21505431..71bda6bbc 100644
--- a/src/extension/internal/cairo-renderer.cpp
+++ b/src/extension/internal/cairo-renderer.cpp
@@ -523,7 +523,9 @@ static void sp_asbitmap_render(SPItem *item, CairoRenderContext *ctx)
     if (pb) {
         //TEST(gdk_pixbuf_save( pb, "bitmap.png", "png", NULL, NULL ));
 
+        ctx->pushState();
         ctx->renderImage(pb.get(), t, item->style);
+        ctx->popState();
     }
 }
 
diff --git a/src/helper/pixbuf-ops.cpp b/src/helper/pixbuf-ops.cpp
index 947af3b50..a79efdbdd 100644
--- a/src/helper/pixbuf-ops.cpp
+++ b/src/helper/pixbuf-ops.cpp
@@ -131,6 +131,9 @@ Inkscape::Pixbuf *sp_generate_internal_bitmap(SPDocument *doc, gchar const */*fi
     // because that would not work if the shown item references something in defs
     if (item_only) {
         hide_other_items_recursively(doc->getRoot(), item_only, dkey);
+        // TODO: The following line forces 100% opacity as required by sp_asbitmap_render() in cairo-renderer.cpp
+        //       Make it contitional if 'item_only' is ever used by other callers which need to retain opacity 
+        item_only->get_arenaitem(dkey)->setOpacity(1.0);
     }
 
     Geom::IntRect final_bbox = Geom::IntRect::from_xywh(0, 0, width, height);