returning 0 is makeplot gives no image

rowers/tasks.py

@@ -1887,13 +1887,16 @@ def handle_makeplot(f1, f2, t, hrdata, plotnr, imagename,
         t += ' - Power Distribution'
         fig1 = row.get_power_piechart(t)
 
-    if fig1:
-        canvas = FigureCanvas(fig1)
+    if fig1 is None:
+        return 0
 
-        canvas.print_figure('static/plots/' + imagename)
-        plt.close(fig1)
-        fig1.clf()
-        gc.collect()
+
+    canvas = FigureCanvas(fig1)
+
+    canvas.print_figure('static/plots/' + imagename)
+    plt.close(fig1)
+    fig1.clf()
+    gc.collect()
 
     return imagename