Merge branch '8379' into cairo

src/cairo-pen.c

@@ -270,7 +270,12 @@ _cairo_pen_vertices_needed (double	    tolerance,
 	/* number of vertices must be even */
 	if (num_vertices % 2)
 	    num_vertices++;
+
+	/* And we must always have at least 4 vertices. */
+	if (num_vertices < 4)
+	    num_vertices = 4;
     }
+
     return num_vertices;
 }
 
@@ -315,6 +320,8 @@ _cairo_pen_find_active_cw_vertex_index (cairo_pen_t *pen,
 	    break;
     }
 
+    assert (i < pen->num_vertices);
+
     *active = i;
 
     return CAIRO_STATUS_SUCCESS;

test/Makefile.am

@@ -43,6 +43,7 @@ get-clip                        \
 get-group-target		\
 get-path-extents                \
 gradient-alpha			\
+infinite-join			\
 leaky-dash			\
 leaky-polygon			\
 line-width			\

test/infinite-join.c

@@ -0,0 +1,80 @@
+/*
+ * Copyright © 2006 Red Hat, Inc.
+ *
+ * Permission to use, copy, modify, distribute, and sell this software
+ * and its documentation for any purpose is hereby granted without
+ * fee, provided that the above copyright notice appear in all copies
+ * and that both that copyright notice and this permission notice
+ * appear in supporting documentation, and that the name of the
+ * copyright holders not be used in advertising or publicity
+ * pertaining to distribution of the software without specific,
+ * written prior permission. The copyright holders make no
+ * representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied
+ * warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+ * SOFTWARE.
+ *
+ * Author: Carl D. Worth <cworth@cworth.org>
+ */
+
+/* Test case for bug #8379:
+ *
+ *	infinite loop when stroking
+ *	https://bugs.freedesktop.org/show_bug.cgi?id=8379
+ */
+
+#include "cairo-test.h"
+
+static cairo_test_draw_function_t draw;
+
+cairo_test_t test = {
+    "infinite-join",
+    "Test case for infinite loop when stroking with round joins",
+    8, 8,
+    draw
+};
+
+static cairo_test_status_t
+draw (cairo_t *cr, int width, int height)
+{
+    /* Paint white, then draw in black. */
+    cairo_set_source_rgb (cr, 1, 1, 1); /* white */
+    cairo_paint (cr);
+    cairo_set_source_rgb (cr, 0, 0, 0); /* black */
+
+    cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+
+    /* scaling 2 times causes a slight rounding error in the ctm.
+     * Without that, the bug doesn't happen. */
+    cairo_scale (cr, 20 / 100., 20 / 100.);
+    cairo_scale (cr, 1. / 20, 1. / 20);
+
+    cairo_set_line_join (cr, CAIRO_LINE_JOIN_ROUND);
+    cairo_set_line_width (cr, 20);
+
+    cairo_translate (cr, -18300, -13200);
+
+    cairo_new_path (cr);
+    cairo_move_to (cr, 18928, 13843);
+    cairo_line_to (cr, 18500, 13843);
+    cairo_line_to (cr, 18500, 13400);
+    cairo_line_to (cr, 18928, 13400);
+    cairo_line_to (cr, 18928, 13843);
+    cairo_stroke (cr);
+
+    return 0;
+}
+
+int
+main (void)
+{
+    return cairo_test (&test);
+}