BUG: Fix UnboundLocalError in contour labelling

dopplershift · dopplershift · commit ca9502eac8ca · 2018-03-07T13:32:15.000-07:00
The code was trying to protect the access of xy1 and xy2 to valid cases,
but unfortunately, for a list, l != -1 doesn't do element-by-element or
return an error--it just always returns True. Therefore it wasn't
actually guarding.
diff --git a/lib/matplotlib/contour.py b/lib/matplotlib/contour.py
@@ -440,7 +440,7 @@ def calc_label_rot_and_inline(self, slc, ind, lw, lc=None, spacing=5):
             # Actually break contours
             if closed:
                 # This will remove contour if shorter than label
-                if np.all(I != -1):
+                if all(i != -1 for i in I):
                     nlc.append(np.row_stack([xy2, lc[I[1]:I[0]+1], xy1]))
             else:
                 # These will remove pieces of contour if they have length zero
