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ZipFile.write fails with bad modification time #45243

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ZipFile.write fails with bad modification time#45243
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3.10 (EOL)end of life3.11only security fixes3.9 (EOL)end of lifestdlibStandard Library Python modules in the Lib/ directorytype-bugAn unexpected behavior, bug, or error

Description

@gradha
gradha
mannequin
opened on Jul 25, 2007
BPO 1760357
Nosy @warsaw, @bitdancer, @briancurtin, @serhiy-storchaka, @tirkarthi
Files
  • debug_session.txt: Debug session showing negative mtime
  • ignore_negative_modification_time.txt: Most likely incorrect fix to avoid this problem
    		•

    Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.

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    GitHub fields:

    assignee = None
closed_at = None
created_at = <Date 2007-07-25.14:54:52.000>
labels = ['type-bug', 'library', '3.9', '3.10', '3.11']
title = 'ZipFile.write fails with bad modification time'
updated_at = <Date 2021-10-20.12:53:55.412>
user = 'https://bugs.python.org/gradha'

    bugs.python.org fields:

    activity = <Date 2021-10-20.12:53:55.412>
actor = 'christian.heimes'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2007-07-25.14:54:52.000>
creator = 'gradha'
dependencies = []
files = ['8133', '8134']
hgrepos = []
issue_num = 1760357
keywords = ['patch']
message_count = 6.0
messages = ['52944', '52945', '55307', '58978', '159533', '348574']
nosy_count = 8.0
nosy_names = ['barry', 'gradha', 'alanmcintyre', 'r.david.murray', 'brian.curtin', 'serhiy.storchaka', 'xtreak', 'Linsey Alvarez']
pr_nums = []
priority = 'normal'
resolution = None
stage = 'test needed'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue1760357'
versions = ['Python 3.9', 'Python 3.10', 'Python 3.11']

    Activity

    1. gradha commented on Jul 25, 2007

      @gradha
      gradhamannequin
      on Jul 25, 2007
      MannequinAuthor

      Running on Windows XP against a networked file server with Windows 2003 I have a file which due to some obscure reason it has a negative modification time as returned by Python os functions. When I look at the file in the explorer the modification time column is blank, and when I view the properties of the file there the modification time is set to the 25th of April of 1906 at 2:03:44.

      If I try to zip this file the zip creation fails with a Value error when the file's st_mtime value is passed to time.localtime().

      I'm attaching a debug session log along with a possible patch to avoid such problems, though maybe the function that returns st_mtime should never return negative values because other library functions expect zero or positive values too.

      In the log you will see that it is a custom rastertech\zipfile.py file that is failing. This is just the SVN development version of zipfile along with some modifications since changes like 1739648 seem to be very low priority. The patch is generated against a clean SVN version.

    2. gradha
      added
      stdlibStandard Library Python modules in the Lib/ directory
      on Jul 25, 2007

    3. gradha commented on Jul 25, 2007

      @gradha
      gradhamannequin
      on Jul 25, 2007
      MannequinAuthor

      File Added: ignore_negative_modification_time.txt

    4. gradha commented on Aug 26, 2007

      @gradha
      gradhamannequin
      on Aug 26, 2007
      MannequinAuthor

      Any progress report on this issue, please?

    5. alanmcintyre commented on Dec 23, 2007

      @alanmcintyre
      alanmcintyremannequin
      on Dec 23, 2007
      Mannequin

      At the moment I don't have a Windows machine available, but on my Mac,
      time.localtime doesn't seem to mind interpreting negative input values.
      So I doubt that forcing timestamps to be non-negative is the way to fix
      this.

      I poked around a bit in the current 2.6 source, and it seems to me that
      in this case the Windows XP localtime function doesn't like a timestamp
      value that was generated by the same platform's stat function. It seems
      like raising a ValueError is the correct thing for the time module to
      do, since it relies on the platform to do the conversions; what should
      zipfile.writestr do? I don't like the idea of silently using some dummy
      timestamp if the conversion of os.stat results fails, and I can't think
      of an alternative at the moment.

    6. briancurtin
      added
      type-bugAn unexpected behavior, bug, or error
      on Jan 17, 2010

    7. serhiy-storchaka commented on Apr 28, 2012

      @serhiy-storchaka
      serhiy-storchaka
      on Apr 28, 2012
      Member

      An alternative is to use the current time, as for stdin.

    8. LinseyAlvarez
      changed the title [-]ZipFile.write fails with bad modification time[/-] [+]Loveubylulu@gmail.com[/+] on Jul 28, 2019
    9. LinseyAlvarez
      changed the title [-]ZipFile.write fails with bad modification time[/-] [+]Loveubylulu@gmail.com[/+] on Jul 28, 2019
    10. LinseyAlvarez
      added
      topic-email
      on Jul 28, 2019

    11. tirkarthi commented on Jul 28, 2019

      @tirkarthi
      tirkarthi
      on Jul 28, 2019
      Member

      Linsey Alvarez, I am not sure how it's related to email. So I am removing the email tag and changing the subject back.

    12. tirkarthi
      removed
      topic-email
      on Jul 28, 2019

    13. 1 remaining item

    14. tirkarthi
      removed
      topic-email
      on Jul 28, 2019
    15. tirkarthi
      changed the title [-]Loveubylulu@gmail.com[/-] [+]ZipFile.write fails with bad modification time[/+] on Jul 28, 2019
    16. tiran
      added
      3.9 (EOL)end of life
      3.10 (EOL)end of life
      3.11only security fixes
      on Oct 20, 2021
    17. ezio-melotti
      transferred this issue fromon Apr 10, 2022
    18. serhiy-storchaka
      added this to @serhiy-storchaka's project python-zipfileon May 8, 2022
    19. serhiy-storchaka
      added this to Zipfile issues 📦on May 19, 2022

    20. Akasurde commented on Jul 3, 2024

      @Akasurde
      Akasurde
      on Jul 3, 2024
      Contributor

      @serhiy-storchaka I think this is already addressed in the current versions of Python.

      >>> os.stat("hello.txt")
os.stat_result(st_mode=33188, st_ino=31001686, st_dev=16777233, st_nlink=1, st_uid=501, st_gid=0, st_size=0, st_atime=-2019621600, st_mtime=-2019621600, st_ctime=1720029468)
>>> os.stat("hello.txt").st_mtime
-2019621600.0
>>> zi.from_file("hello.txt")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'ZipFile' object has no attribute 'from_file'
>>> info = zipfile.ZipInfo.from_file("hello.txt")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.9/lib/python3.9/zipfile.py", line 517, in from_file
    zinfo = cls(arcname, date_time)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.9/lib/python3.9/zipfile.py", line 361, in __init__
    raise ValueError('ZIP does not support timestamps before 1980')
ValueError: ZIP does not support timestamps before 1980
>>> zi.write("hello.txt")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.9/lib/python3.9/zipfile.py", line 1727, in write
    zinfo = ZipInfo.from_file(filename, arcname,
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.9/lib/python3.9/zipfile.py", line 517, in from_file
    zinfo = cls(arcname, date_time)
  File "/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.9/lib/python3.9/zipfile.py", line 361, in __init__
    raise ValueError('ZIP does not support timestamps before 1980')
ValueError: ZIP does not support timestamps before 1980

    21. msullivan commented on Oct 13, 2026

      @msullivan
      msullivan
      on Oct 13, 2026
      Contributor

      I checked on windows, and on 3.14 and earlier, I got OSError, but on 3.15 I get "ZIP does not support timestamps before 1980" and passing strict_timestamps=False will fix that.

      Fix was presumably #143463, which fixes negative timestamps on windows.

      I think this can be closed.

    22. github-project-automation
      moved this to Todo in Project_VKon Oct 18, 2026
    23. kevinprimeraquecreo-stack
      added this to Project_VKand Project_VKon Oct 18, 2026
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