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gh-159185: Document that PyMarshal_WriteObjectToFile can silently truncate before 3.16 - #159201
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…lently before 3.16 In Python 3.15 and earlier, PyMarshal_WriteObjectToFile() ignores most marshalling errors and all I/O errors: it returns without setting the error indicator after writing only part of the data. PyMarshal_WriteLongToFile() ignores I/O errors in the same way. That was fixed in 3.16 by pythongh-155907, which is not backported. Tell the users of the older versions so that they can check what was written.
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Thanks @gpshead for the PR 🌮🎉.. I'm working now to backport this PR to: 3.14, 3.15. |
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GH-159202 is a backport of this pull request to the 3.15 branch. |
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GH-159203 is a backport of this pull request to the 3.14 branch. |
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…tly truncate before 3.16 (GH-159201) (#159202) gh-159185: Document that PyMarshal_WriteObjectToFile can silently truncate before 3.16 (GH-159201) gh-159185: Document that the PyMarshal file writers can fail silently before 3.16 In Python 3.15 and earlier, PyMarshal_WriteObjectToFile() ignores most marshalling errors and all I/O errors: it returns without setting the error indicator after writing only part of the data. PyMarshal_WriteLongToFile() ignores I/O errors in the same way. That was fixed in 3.16 by gh-155907, which is not backported. Tell the users of the older versions so that they can check what was written. (cherry picked from commit b3714a5) Co-authored-by: Gregory P. Smith <68491+gpshead@users.noreply.github.com>
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…tly truncate before 3.16 (GH-159201) (#159203) gh-159185: Document that PyMarshal_WriteObjectToFile can silently truncate before 3.16 (GH-159201) gh-159185: Document that the PyMarshal file writers can fail silently before 3.16 In Python 3.15 and earlier, PyMarshal_WriteObjectToFile() ignores most marshalling errors and all I/O errors: it returns without setting the error indicator after writing only part of the data. PyMarshal_WriteLongToFile() ignores I/O errors in the same way. That was fixed in 3.16 by gh-155907, which is not backported. Tell the users of the older versions so that they can check what was written. (cherry picked from commit b3714a5) Co-authored-by: Gregory P. Smith <68491+gpshead@users.noreply.github.com>
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In Python 3.15 and earlier,
PyMarshal_WriteObjectToFile()can return without setting the error indicator after writing only part of the data, for example when the value contains an unmarshallable object or the write fails. That was fixed in 3.16 by gh-155907, which was deliberately not backported. This adds a note so that users of the older versions know to check what was written or use an alternate API. Docs only; intended for backport to 3.15 and 3.14.marshal.dumps()crashes when a set is modified while it is being marshalled #159185