Previously the module name was used, which broke relative imports when pdb was run against a plain module or submodule.

Add a new argument "-m" to the pdb module to allow
users to run `python -m pdb -m my_module_name`.

This relies on private APIs in the runpy module to work,
but we can get away with that since they're both part of
the standard library and can be updated together if
the runpy internals get refactored.

* Give pdb.set_trace() an optional `header` argument

* What's new.

* Give pdb.set_trace() an optional `header` argument

* What's new.

* Remove Setup.config
* Always define WITH_THREAD for compatibility.

* Use "with Popen" to cleanup properly the process
* Use support.temp_cwd() to properly change the working directory
* Use environ.pop() to cleanup the code

HOME is not set on Windows for example.

Use also textwrap.dedent() for the script.

Patch by Martin Matusiak and Sam Kimbrel.

Most fixes to Doc/ and Lib/ directories by Ville Skyttä.

in an infinite loop.  Patch by Xavier de Gaye.

Closes #18714.

So that it no longer shadows the print function.

Patch by Connor Osborn, doc and test changes by R. David Murray.

Patch by Ilya Sandler.

issue13183 - Fix pdb skipping frames after hitting a breakpoint and running step. Patch by Xavier de Gaye

issue13183 - Fix pdb skipping frames after hitting a breakpoint and running step. Patch by Xavier de Gaye

Many tests simply didn't care if they unset a pre-existing trace function. This
made test coverage impossible. This patch fixes various tests to put back any
pre-existing trace function. It also introduces test.support.no_tracing as a
decorator which will temporarily unset the trace function for tests which
simply fail otherwise.

Thanks to Kristian Vlaardingerbroek for helping to find the cause of various
trace function unsets.