[issue30767] logging must check exc_info correctly

[Mihail Krivushin]

New submission from Mihail Krivushin:

Logging checking `if exc_info:` and this maybe incorrect, due exception instance can have __bool__ method and thus can be false. If this is a case, then error that is return false from __bool__ will cause logging to swallow traceback. We need to check exc_info correctly. Will do PR myself.

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components: Library (Lib)
messages: 296892
nosy: krivushinme
priority: normal
severity: normal
status: open
title: logging must check exc_info correctly

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue30767>
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