Fix rendering failures caused by markers with markerUnits="strokeWidth"

on shapes with zero stroke width

(bzr r9508.1.56)

2 files changed, 9 insertions, 1 deletions

diff --git a/src/display/nr-arena-shape.cpp b/src/display/nr-arena-shape.cpp
index 8a2b27f4f..550195c7c 100644
--- a/src/display/nr-arena-shape.cpp
+++ b/src/display/nr-arena-shape.cpp
@@ -370,6 +370,7 @@ nr_arena_shape_render(cairo_t *ct, NRArenaItem *item, NRRectL *area, NRPixBlock
         // to render svg:pattern
         has_fill   = shape->nrstyle.prepareFill(ct, &shape->paintbox);
         has_stroke = shape->nrstyle.prepareStroke(ct, &shape->paintbox);
+        has_stroke &= (shape->nrstyle.stroke_width != 0);
 
         if (has_fill || has_stroke) {
             // TODO: remove segments outside of bbox when no dashes present
@@ -387,7 +388,7 @@ nr_arena_shape_render(cairo_t *ct, NRArenaItem *item, NRRectL *area, NRPixBlock
         cairo_restore(ct);
     }
 
-    /* Render markers into parent buffer */
+    // marker rendering
     for (NRArenaItem *child = shape->markers; child != NULL; child = child->next) {
         unsigned int ret = nr_arena_item_invoke_render(ct, child, area, pb, flags);
         if (ret & NR_ARENA_ITEM_STATE_INVALID) return ret;
diff --git a/src/marker.cpp b/src/marker.cpp
index 6917c0b71..f89dd2bc0 100644
--- a/src/marker.cpp
+++ b/src/marker.cpp
@@ -614,6 +614,13 @@ sp_marker_show_instance ( SPMarker *marker, NRArenaItem *parent,
                           unsigned int key, unsigned int pos,
                           Geom::Matrix const &base, float linewidth)
 {
+    // do not show marker if linewidth == 0 and markerUnits == strokeWidth
+    // otherwise Cairo will fail to render anything on the tile
+    // that contains the "degenerate" marker
+    if (marker->markerUnits == SP_MARKER_UNITS_STROKEWIDTH && linewidth == 0) {
+        return NULL;
+    }
+
     for (SPMarkerView *v = marker->views; v != NULL; v = v->next) {
         if (v->key == key) {
             if (pos >= v->items.size()) {