Merge pull request #10492 from anntzer/drag-pan

dstansby · web-flow · commit 3c70841d5f0b · 2018-02-16T18:06:26.000Z
Avoid UnboundLocalError in drag_pan.
diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
@@ -4017,7 +4017,7 @@ def format_deltas(key, dx, dy):
         p = self._pan_start
         dx = x - p.x
         dy = y - p.y
-        if dx == 0 and dy == 0:
+        if dx == dy == 0:
             return
         if button == 1:
             dx, dy = format_deltas(key, dx, dy)
@@ -4038,6 +4038,8 @@ def format_deltas(key, dx, dy):
             except OverflowError:
                 warnings.warn('Overflow while panning')
                 return
+        else:
+            return
 
         valid = np.isfinite(result.transformed(p.trans))
         points = result.get_points().astype(object)
