Call to _imp.source_hash with incorrect arguments in (unreachable?) part of SourceLoader.get_code (importlib._bootstrap_external)

[DavidCEllis]

Bug report

As far as I can tell this line:

cpython/Lib/importlib/_bootstrap_external.py

Line 1147 in 4e4b13e

source_hash = _imp.source_hash(source_bytes)

will raise a TypeError and should be a 2 argument form as seen earlier in the same method.

cpython/Lib/importlib/_bootstrap_external.py

Lines 1117 to 1120 in 4e4b13e

	source_hash = _imp.source_hash(
	_RAW_MAGIC_NUMBER,
	source_bytes,
	)

However, as either hash_based is False, source_hash has already been generated or the code returns early I don't think this line can be reached. (Maybe if you have a flaky version of get_data that sometimes raises an ImportError/EOFError??).

Example:

>>> _imp.source_hash(_RAW_MAGIC_NUMBER, b'')
b's\x8d\x9c\xd5\xd5\xe8\x7fs'

>>> _imp.source_hash(b'')
Traceback (most recent call last):
 File "/opt/local/Library/Frameworks/Python.framework/Versions/3.11/lib/python3.11/code.py", line 90, in runcode
 exec(code, self.locals)
 File "<input>", line 1, in <module>
TypeError: source_hash() missing required argument 'source' (pos 2)

Edit: Sorry, as I opened the issue from within the source line via 'reference in new issue' I think I accidentally skipped the bug report format that would have given this a label.

Linked PRs

• gh-99508: fix TypeError in Lib/importlib/_bootstrap_external.py #99635

[sobolevn]

Yes, this seems incorrect. _imp.source_hash always has two arguments, here one is used.

[FFY00]

It seems this was a bug of #4575, which went unnoticed until now. Looks like it is just missing _RAW_MAGIC_NUMBER as the first argument.