[issue24583] set.update(): Crash when source set is changed during merging

[Raymond Hettinger]

Raymond Hettinger added the comment:

Added a variant patch that brings the steps together in a more logical manner (single entry point at the top and the named exits at the bottom, brings refcount adjustment logic together in a more coherent way).  The "restart" target is done the same way as the "top" target in dictobject.c.   Added a comment explaining why the pre-increment is necessary.

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Added file: http://bugs.python.org/file39957/set_self_contained.diff

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