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mywrite() ignores PyFile_WriteString() errors #52371

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vstinner opened this issue Mar 12, 2010 · 7 comments
Closed

mywrite() ignores PyFile_WriteString() errors #52371

vstinner opened this issue Mar 12, 2010 · 7 comments
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interpreter-core (Objects, Python, Grammar, and Parser dirs) type-bug An unexpected behavior, bug, or error

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@vstinner
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BPO 8124
Nosy @vstinner
Files
  • mywrite_nosignal.patch
    		•

    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 = <Date 2010-04-23.12:05:11.764>
created_at = <Date 2010-03-12.16:08:37.945>
labels = ['interpreter-core', 'type-bug']
title = 'mywrite() ignores PyFile_WriteString() errors'
updated_at = <Date 2010-04-23.12:05:11.762>
user = 'https://github.com/vstinner'

    bugs.python.org fields:

    activity = <Date 2010-04-23.12:05:11.762>
actor = 'vstinner'
assignee = 'none'
closed = True
closed_date = <Date 2010-04-23.12:05:11.764>
closer = 'vstinner'
components = ['Interpreter Core']
creation = <Date 2010-03-12.16:08:37.945>
creator = 'vstinner'
dependencies = []
files = ['17045']
hgrepos = []
issue_num = 8124
keywords = ['patch']
message_count = 7.0
messages = ['100939', '100942', '103711', '103946', '103948', '103949', '104006']
nosy_count = 1.0
nosy_names = ['vstinner']
pr_nums = []
priority = 'normal'
resolution = 'fixed'
stage = None
status = 'closed'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue8124'
versions = ['Python 3.1', 'Python 3.2']
    @vstinner
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    PyFile_WriteString() calls PyObject_Str() which calls PyErr_CheckSignals(). If a signal was catched, the signal handler is called. If the signal handler raises an error, PyObject_Str() and then PyFile_WriteString() return NULL.

    mywrite() ignores all PyFile_WriteString() errors. It should maybe only ignores errors from the file (except IOError: ...) and not any error.

    Another problem: mywrite() is called from PySys_WriteStdout() and PySys_WriteStderr() which are procedures. PySys_WriteStdout()/PySys_WriteStderr() caller cannot detect the error. There are 65 calls to PySys_WriteStd...

    @vstinner vstinner added interpreter-core (Objects, Python, Grammar, and Parser dirs) type-bug An unexpected behavior, bug, or error labels Mar 12, 2010
    @vstinner
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    This bug is related to bpo-3137.

    @vstinner
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    Another solution: disable call to PyErr_CheckSignals() in mywrite().

    @vstinner
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    Attached patch fixes this issue: PyFile_WriteObject() doesn't call PyObject_Str() to avoid PyErr_CheckSignals(). I'm not sure that it's the right approch because it may change the behaviour of existing code when getting a signal.

    @vstinner
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    Ok, forget my pyfile_writeobject_nosignal.patch, it's not the right approach.

    New patch: mywrite() uses its own implementation PyFile_WriteString(), sys_pyfile_write(), which doesn't call PyErr_CheckSignals():

    /* Implementation of PyFile_WriteString() no calling PyErr_CheckSignals():

    • mywrite() should not execute any Python signal handler to avoid raising an
    • error because mywrite() ignores all errors */

    @vstinner
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    The goal is this issue is also to catch SIGINT when starting Python. It now works in Python trunk and py3k, but not in verbose mode because mywrite() eats errors (especially the KeyboardInterrupt raised by the default SIGINT handler) and calls indirectly Python signal handlers.

    @vstinner
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    Commited: r80404 (py3k), r80405 (3.1).

    @ezio-melotti ezio-melotti transferred this issue from another repository Apr 10, 2022
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