Fix ToolManager + TextBox support.

Try running e.g. examples/widgets/textbox.py together with
`rcParams["toolbar"] = "toolmanager"`.  Before this fix, clicking on the
TextBox would result in "TypeError: push() takes 2 positional arguments
but 3 were given".

Author: anntzer

lib/matplotlib/tests/test_widgets.py

@@ -619,7 +619,11 @@ def test_CheckButtons():
     check.disconnect(cid)
 
 
-def test_TextBox():
+@pytest.mark.parametrize("toolbar", ["none", "toolbar2", "toolmanager"])
+def test_TextBox(toolbar):
+    # Avoid "toolmanager is provisional" warning.
+    dict.__setitem__(plt.rcParams, "toolbar", toolbar)
+
     from unittest.mock import Mock
     submit_event = Mock()
     text_change_event = Mock()

lib/matplotlib/widgets.py

@@ -1287,7 +1287,7 @@ def begin_typing(self, x):
             # If using toolmanager, lock keypresses, and plan to release the
             # lock when typing stops.
             toolmanager.keypresslock(self)
-            stack.push(toolmanager.keypresslock.release, self)
+            stack.callback(toolmanager.keypresslock.release, self)
         else:
             # If not using toolmanager, disable all keypress-related rcParams.
             # Avoid spurious warnings if keymaps are getting deprecated.