Adapt tkinter and IDLE tests to the upcoming Tcl/Tk releases #161441

Some tkinter and IDLE tests fail with the current development versions of Tcl/Tk: core-8-6-branch, core-9-0-branch (the 9.0.5 release candidate) and trunk. The released versions 8.6.18, 9.0.4 and 9.1.0 are not affected.

This issue is kept open, because new such failures are expected while Tcl/Tk development continues.

idlelib.idle_test.test_editmenu.PasteTest.test_paste_entry fails with AssertionError: 'one' != 'onetwo' for a ttk entry with an empty selection range.

ttk widgets are no longer realized in their constructor (3d4a73e5eba6, a fix for 88ffa70453), and an event generated for a widget whose window does not exist yet is silently dropped. This has always been the behavior; ttk widgets only escaped it because they were realized early. The test should force its widgets into existence, as the Tk test suite now does in spinbox.test.

test_tkinter.test_font.FontTest.test_existing and test_tcl_object fail with AssertionError: 'normal' != 'bold'.

test_equality() creates a named font whose name is the string form of a font description, Times 20 bold, which is also used by other tests sharing the same root. Creating it now permanently makes that description resolve to the named font (a344fe53e96e, a fix for c81e0ccee2), and deleting the font does not restore it. Such a name was never supported, it was only covered for completeness, so the check should simply be removed.

Linked PRs

• gh-161441: Fix tkinter and IDLE tests failing with new Tcl/Tk #161442