From 5490e44e40dd6fa00661abd8d303fe2dc6fc443a Mon Sep 17 00:00:00 2001
From: Paul Vincent Craven <paul@cravenfamily.com>
Date: Tue, 24 Mar 2020 10:13:38 -0500
Subject: [PATCH] Fix for issue #616, create line strip command is exiting
 early. Also add in unit test to catch the error in the future.

---
 arcade/buffered_draw_commands.py        |  6 ++--
 tests/unit2/test_buffered_line_strip.py | 47 +++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 tests/unit2/test_buffered_line_strip.py

diff --git a/arcade/buffered_draw_commands.py b/arcade/buffered_draw_commands.py
index a3a950beb..aa6ef0f29 100644
--- a/arcade/buffered_draw_commands.py
+++ b/arcade/buffered_draw_commands.py
@@ -191,6 +191,8 @@ def create_line_strip(point_list: PointList,
     Create a multi-point line to be rendered later. This works faster than draw_line because
     the vertexes are only loaded to the graphics card once, rather than each frame.
 
+    Internally, thick lines are created by two triangles.
+
     :param PointList point_list:
     :param Color color:
     :param PointList line_width:
@@ -214,8 +216,8 @@ def create_line_strip(point_list: PointList,
             new_color_list += color1, color2, color1, color2
             triangle_point_list += points[1], points[0], points[2], points[3]
 
-            shape = create_triangles_filled_with_colors(triangle_point_list, new_color_list)
-            return shape
+        shape = create_triangles_filled_with_colors(triangle_point_list, new_color_list)
+        return shape
 
 
 def create_line_loop(point_list: PointList,
diff --git a/tests/unit2/test_buffered_line_strip.py b/tests/unit2/test_buffered_line_strip.py
new file mode 100644
index 000000000..9b0caa268
--- /dev/null
+++ b/tests/unit2/test_buffered_line_strip.py
@@ -0,0 +1,47 @@
+import arcade
+
+SCREEN_WIDTH = 800
+SCREEN_HEIGHT = 600
+
+
+class MyGame(arcade.Window):
+    """ Main application class. """
+
+    def __init__(self, width, height):
+        """
+        Initializer
+        """
+        super().__init__(width, height)
+
+        arcade.set_background_color(arcade.color.WHITE)
+
+        point_list = ([0, 100],
+                     [100, 100],
+                      [100, 300],
+                      [300, 300])
+        self.line_strip = arcade.create_line_strip(point_list, arcade.csscolor.BLACK, 10)
+
+    def on_draw(self):
+        arcade.start_render()
+        self.line_strip.draw()
+        p = arcade.get_pixel(0, 100)
+        assert p == (0, 0, 0)
+        p = arcade.get_pixel(0, 95)
+        assert p == (0, 0, 0)
+        p = arcade.get_pixel(0, 94)
+        assert p == (255, 255, 255)
+        p = arcade.get_pixel(50, 100)
+        assert p == (0, 0, 0)
+        p = arcade.get_pixel(100, 200)
+        assert p == (0, 0, 0)
+        p = arcade.get_pixel(150, 300)
+        assert p == (0, 0, 0)
+        p = arcade.get_pixel(301, 300)
+        assert p == (255, 255, 255)
+
+
+def test_main():
+    """ Main method """
+    window = MyGame(SCREEN_WIDTH, SCREEN_HEIGHT)
+    window.test()
+    window.close()