[3.14] gh-156995: Fix _PyBytes_Resize() in Free Threading (#156996) - #157373
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On Free Threading, _PyBytes_Resize(&obj, 1) no longer returns a single byte singleton if the current thread is different than the thread which created the object. Co-authored-by: Cody Maloney <[email protected]> Co-authored-by: Victor Stinner <[email protected]> (cherry picked from commit fd569ea)
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I failed to find a function in Python 3.14 stdlib which still mutates the bytes object after calling bytes = PyBytes_FromStringAndSize(NULL, size);
... write into bytes ...
_PyBytes_Resize(&bytes, n);
return bytes; // bytes no longer mutated from this pointThere is |
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This change should be backported to Python 3.13, but the fix there is different because _PyBytes_Resize() doesn't test |
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…on#156996) (python#157373) _PyBytes_Resize(&obj, 1) no longer returns a single byte singleton if the reference count is greater than 1. (cherry picked from commit fd569ea) Co-authored-by: Stan Ulbrych <[email protected]> Co-authored-by: Cody Maloney <[email protected]> Co-authored-by: Victor Stinner <[email protected]>
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GH-157436 is a backport of this pull request to the 3.14 branch. |
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GH-157436 is a backport of this pull request to the 3.13 branch. |
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…157373) (#157436) [3.14] gh-156995: Fix _PyBytes_Resize() in Free Threading (#156996) (#157373) _PyBytes_Resize(&obj, 1) no longer returns a single byte singleton if the reference count is greater than 1. (cherry picked from commit fd569ea) Co-authored-by: Stan Ulbrych <[email protected]> Co-authored-by: Cody Maloney <[email protected]>
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Sep 14, 2026
| @@ -0,0 +1,3 @@ | |||
| On Free Threading, ``_PyBytes_Resize(&obj, 1)`` no longer returns a single byte | |||
| singleton is the current thread is different than the thread which created the | |||
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| singleton is the current thread is different than the thread which created the | |
| singleton if the current thread is different than the thread which created the |
nit, is -> if
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On Free Threading, _PyBytes_Resize(&obj, 1) no longer returns a single byte singleton is the current thread is different than the thread which created the object.
(cherry picked from commit fd569ea)
bytearray.take_bytes()can corrupt shared single-byte bytes objects #156995