Merge pull request #3337 from tacaswell/bxp_flier_colors

BUG : don't assign color or marker to flier props if None

lib/matplotlib/axes/_axes.py

@@ -3298,12 +3298,14 @@ def bxp(self, bxpstats, positions=None, widths=None, vert=True,
                 # process the symbol string
                 # discarded linestyle
                 _, marker, color = _process_plot_format(sym)
-                flierprops['marker'] = marker
-                flierprops['color'] = color
-                # assume that if color is passed in the user want
-                # filled symbol
-                flierprops['markeredgecolor'] = color
-                flierprops['markerfacecolor'] = color
+                if marker is not None:
+                    flierprops['marker'] = marker
+                if color is not None:
+                    flierprops['color'] = color
+                    # assume that if color is passed in the user want
+                    # filled symbol
+                    flierprops['markeredgecolor'] = color
+                    flierprops['markerfacecolor'] = color
             final_flierprops.update(flierprops)
 
         # median line properties

lib/matplotlib/tests/test_axes.py

@@ -1529,6 +1529,20 @@ def test_boxplot():
     ax.set_ylim((-30, 30))
 
 
+@image_comparison(baseline_images=['boxplot_sym2'],
+                  remove_text=True, extensions=['png'])
+def test_boxplot_sym2():
+    x = np.linspace(-7, 7, 140)
+    x = np.hstack([-25, x, 25])
+    fig, [ax1, ax2] = plt.subplots(1, 2)
+
+    ax1.boxplot([x, x], bootstrap=10000, sym='^')
+    ax1.set_ylim((-30, 30))
+
+    ax2.boxplot([x, x], bootstrap=10000, sym='g')
+    ax2.set_ylim((-30, 30))
+
+
 @image_comparison(baseline_images=['boxplot_sym'],
                   remove_text=True, extensions=['png'],
                   savefig_kwarg={'dpi': 40})