matplotlib
diff --git a/‎lib/matplotlib/collections.py
Copy file name to clipboardExpand all lines: lib/matplotlib/collections.py
+6-3Lines changed: 6 additions & 3 deletions b/‎lib/matplotlib/collections.py
Copy file name to clipboardExpand all lines: lib/matplotlib/collections.py
+6-3Lines changed: 6 additions & 3 deletions
diff --git a/‎lib/matplotlib/tests/test_collections.py
Copy file name to clipboardExpand all lines: lib/matplotlib/tests/test_collections.py
+7Lines changed: 7 additions & 0 deletions b/‎lib/matplotlib/tests/test_collections.py
Copy file name to clipboardExpand all lines: lib/matplotlib/tests/test_collections.py
+7Lines changed: 7 additions & 0 deletions
@@ -1456,12 +1456,15 @@ def __init__(self,
         --------
         .. plot:: gallery/lines_bars_and_markers/eventcollection_demo.py
         """
-
+        if positions is None:
+            raise ValueError('positions must be an array-like object')
+        # Force a copy of positions
+        positions = np.array(positions, copy=True)
         segment = (lineoffset + linelength / 2.,
                    lineoffset - linelength / 2.)
-        if positions is None or len(positions) == 0:
+        if positions.size == 0:
             segments = []
-        elif hasattr(positions, 'ndim') and positions.ndim > 1:
+        elif positions.ndim > 1:
             raise ValueError('positions cannot be an array with more than '
                              'one dimension.')
         elif (orientation is None or orientation.lower() == 'none' or
 
@@ -711,3 +711,10 @@ def test_pathcollection_legend_elements():
         ax.add_artist(l)
 
     fig.canvas.draw()
+
+
+def test_EventCollection_nosort():
+    # Check that EventCollection doesn't modify input in place
+    arr = np.array([3, 2, 1, 10])
+    coll = EventCollection(arr)
+    np.testing.assert_array_equal(arr, np.array([3, 2, 1, 10]))