fix issue 6921 and add tests

kalagau · kalagau · commit f3b82c12e628 · 2017-04-17T20:41:38.000+01:00
Fix Error: local variable 'xdata' referenced before assignment" in legend_handler.py
diff --git a/lib/matplotlib/legend_handler.py b/lib/matplotlib/legend_handler.py
@@ -147,22 +147,20 @@ def get_numpoints(self, legend):
 
     def get_xdata(self, legend, xdescent, ydescent, width, height, fontsize):
         numpoints = self.get_numpoints(legend)
-
         if numpoints > 1:
-            # we put some pad here to compensate the size of the
-            # marker
+            # we put some pad here to compensate the size of the marker
             pad = self._marker_pad * fontsize
             xdata = np.linspace(-xdescent + pad,
                                 -xdescent + width - pad,
                                 numpoints)
             xdata_marker = xdata
-        elif numpoints == 1:
-            xdata = np.linspace(-xdescent, -xdescent+width, 2)
+        else:
+            xdata = np.linspace(-xdescent, -xdescent + width, 2)
             xdata_marker = [-xdescent + 0.5 * width]
-
         return xdata, xdata_marker
 
 
+
 class HandlerNpointsYoffsets(HandlerNpoints):
     def __init__(self, numpoints=None, yoffsets=None, **kw):
         HandlerNpoints.__init__(self, numpoints=numpoints, **kw)
diff --git a/lib/matplotlib/tests/test_legend.py b/lib/matplotlib/tests/test_legend.py
@@ -331,3 +331,11 @@ def test_linecollection_scaled_dashes():
     for oh, lh in zip((lc1, lc2, lc3), (h1, h2, h3)):
         assert oh.get_linestyles()[0][1] == lh._dashSeq
         assert oh.get_linestyles()[0][0] == lh._dashOffset
+
+
+def test_handler_numpoints():
+    '''test legend handler with numponts less than or equal to 1'''
+    # related to #6921 and PR #8478
+    fig, ax = plt.subplots()
+    ax.plot(range(5), label='test')
+    ax.legend(numpoints=0.5)
