Fixed joysticks test segfault.

README.md

@@ -35,6 +35,7 @@ guide in the GLFW documentation.
    documentation is built
  - Renamed configuration header to `glfw_config.h` to avoid conflicts
  - Bugfix: The `glfw3.pc` file did not respect the `LIB_SUFFIX` CMake option
+ - Bugfix: The `joysticks` test would segfault if a controller had no axes
  - [Win32] Bugfix: Removed joystick axis value negation left over from GLFW 2
  - [Win32] Bugfix: Restoring windows using the Win+D hot key did not trigger the
                    focus callback

tests/joysticks.c

@@ -64,14 +64,12 @@ static void framebuffer_size_callback(GLFWwindow* window, int width, int height)
 static void draw_joystick(Joystick* j, int x, int y, int width, int height)
 {
     int i;
-    int axis_width, axis_height;
-    int button_width, button_height;
+    const int axis_height = 3 * height / 4;
+    const int button_height = height / 4;
 
-    axis_width = width / j->axis_count;
-    axis_height = 3 * height / 4;
-
-    button_width = width / j->button_count;
-    button_height = height / 4;
+    if (j->axis_count)
+    {
+        const int axis_width = width / j->axis_count;
 
         for (i = 0;  i < j->axis_count;  i++)
         {
@@ -89,6 +87,11 @@ static void draw_joystick(Joystick* j, int x, int y, int width, int height)
                     x + (i + 1) * axis_width,
                     y + 5 + (int) (value * (axis_height - 5)));
         }
+    }
+
+    if (j->button_count)
+    {
+        const int button_width = width / j->button_count;
 
         for (i = 0;  i < j->button_count;  i++)
         {
@@ -103,6 +106,7 @@ static void draw_joystick(Joystick* j, int x, int y, int width, int height)
                     y + axis_height + button_height);
         }
     }
+}
 
 static void draw_joysticks(GLFWwindow* window)
 {