This associates the message box with the widget and is better for Mac OSX.
Patch by Mark Roseman.

Some of the calls to the Frm class were buggy anyway.

The height is reduced by 3/4 to account for extra spacing between lines,
relative to an Idle editor, and extra tall header lines.

by adding a new tag.  Patch by Mark Roseman. Also give <pre> text a very
light blueish-gray background similar to that used by Sphinx html.

* Change limit type from unsigned int to Py_UCS4, to use the same type than the
  "ch" variable (an Unicode character).
* Reuse ch variable for _Py_ERROR_XMLCHARREFREPLACE
* Add some newlines for readability

Fixed error creation if the problem is an empty expression in an f-string: use ast_error instead of PyErr_SetString.

Patch by Benjamin Hodgson.

Patch written by Prashant Tyagi.

to finish making current README.txt obsolete.

Start to split regrtest.py into smaller parts with the creation of
Lib/test/libregrtest/cmdline.py.