Incorrect exception handling in Tab Nanny

[Wulian233]

Bug report

Bug description:

In the Lib/tabnanny.py module, the exception handling for IndentationError might not be reachable after SyntaxError is caught and a return statement is executed.

See https://github.com/python/cpython/blob/main/Lib/tabnanny.py#L108-L114

    except SyntaxError as msg:
        errprint("%r: Token Error: %s" % (file, msg))
        return

    except IndentationError as msg:
        errprint("%r: Indentation Error: %s" % (file, msg))
        return

Why This Happens:
According to https://docs.python.org/3/library/exceptions.html#exception-hierarchy , we can learn that SyntaxError detection range than IndentationError bigger, Is the inclusion relationship. IndentationError is written after SyntaxError, which causes the program to never execute IndentationError

How to Fix:
We need to put the more specific IndentationError before SyntaxError

Linked PRs

• gh-120495: Fix incorrect exception handling in Tab Nanny #120498
• [3.13] gh-120495: Fix incorrect exception handling in Tab Nanny (GH-120498) #120548
• [3.12] gh-120495: Fix incorrect exception handling in Tab Nanny (GH-120498) #120549