bobf32@gmail.com writes:

> ...
> I expect two replacements to be made, and all the invisible text to be
> ignored. What actually happens is that the text is appended to all lines
> under the ** B and ** C headings plus the two desired headings
> themselves.

Canceled.
It is a bug in Emacs.
See https://debbugs.gnu.org/cgi/bugreport.cgi?bug=64178

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Ihor Radchenko // yantar92,
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