Remove infinite looping when stroking with a line width at or close to 0.0. Thanks to Rob Buis <buis@kde.org> and Noah Levitt <nlevitt@columbia.edu> for providing in-the-wild examples of SVG files with stroke-width:0 that demonstrated the problem, (cowboy.svg and albania.svg).

Do nothing if the pen is a degenerate, single point. This happens when the line width is a very small, non-zero value.
Do nothing when asked to stroke a path with a line_width of 0.0. Previously, this would lead to an infinite loop.
Force negative line width to 0.0.
Updated TODO list.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/cairo-pen.c b/src/cairo-pen.c
index ce876a31..dd054372 100644
--- a/src/cairo-pen.c
+++ b/src/cairo-pen.c
@@ -322,6 +322,11 @@ _cairo_pen_stroke_spline (cairo_pen_t		*pen,
     cairo_status_t status;
     cairo_polygon_t polygon;
 
+    /* If the line width is so small that the pen is reduced to a
+       single point, then we have nothing to do. */
+    if (pen->num_vertices <= 1)
+	return CAIRO_STATUS_SUCCESS;
+
     _cairo_polygon_init (&polygon);
 
     status = _cairo_spline_decompose (spline, tolerance);