Hi Steve, Have you considered and rejected filing a bug on bugs.python.org?
Or are you specifically concerned about how to write a test for this behavior that doesn't fill up the disk when the bug is present? On Unixoid systems there's a resource limit you can set to limit disk space IIRC (e.g. on my Mac, `ulimit -a` shows various limits including file size). Solving this by patching write() seems somewhat complex because you'd really have to patch open() to return an io.IO subclass that has a patched write() method. But I'm sure it can be done in the context of a specific test. I wouldn't try patching it for *all* tests though -- there are many tests that might fail due to such a change. It also wouldn't help for file operations made directly from C code. --Guido On Thu, May 21, 2020 at 6:57 AM Steve Barnes <gadgetst...@live.co.uk> wrote: > The issue is simple and simple enough for a beginner to fall foul of - > test procedure: > Change directory to any directory with files in totally a few 10s of megs > (ideally but it doesn't matter much). > python -m zipfile -c my_zipfile.zip . > > Wait a few minutes and press control-C then do a directory - you will find > that my_zipfile.zip is huge (much bigger than the total of the files in the > original directory). The same applies to tarfile. > > If you fail to hit control-C soon enough (how long depends on the spare > space on the current drive) it will crash when it runs out of disk space, > possibly, on some systems, requiring a format and re-install of the OS. > > The cause of the problem is that when zipfile &/or tarfile is archiving to > a file in the current directory it tries to add the target file to the > input list and you have an Ouroboros situation. The fix is also simple - > exclude the target file from the permitted inputs. > > I have seen this happen in the wild, I do know that python is not the only > archiving tool that suffers from this problem but that seems to me to be no > reason not to address this. > > If write were patched to simply count the bytes but not write the file > then the problem would not occur so I guess that it would need to be > patched in a transparent manner. > > Steve Barnes > > -----Original Message----- > From: remi.lape...@henki.fr <remi.lape...@henki.fr> > Sent: 21 May 2020 13:56 > To: python-ideas@python.org > Subject: [Python-ideas] Re: How to propose a change with tests where the > failing test case (current behaviour) is bad or dangerous > > If the file is supposed to be small, would patching write() in the test to > accumulate the number of bytes written and fail the test when it goes over > what it's supposed to be possible? > > What is the issue? > _______________________________________________ > Python-ideas mailing list -- python-ideas@python.org To unsubscribe send > an email to python-ideas-le...@python.org > https://mail.python.org/mailman3/lists/python-ideas.python.org/ > Message archived at > https://mail.python.org/archives/list/python-ideas@python.org/message/ORPDN4CITJZSO246HWCKNZUKA4IT3QWC/ > Code of Conduct: http://python.org/psf/codeofconduct/ > _______________________________________________ > Python-ideas mailing list -- python-ideas@python.org > To unsubscribe send an email to python-ideas-le...@python.org > https://mail.python.org/mailman3/lists/python-ideas.python.org/ > Message archived at > https://mail.python.org/archives/list/python-ideas@python.org/message/OT5M4U4RPJAU7HXXFONGTL442OCHGSXY/ > Code of Conduct: http://python.org/psf/codeofconduct/ > -- --Guido van Rossum (python.org/~guido) *Pronouns: he/him **(why is my pronoun here?)* <http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/>
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