Okay. I just set "set enable-bracketed-paste off" in my /etc/inputrc.
Perhaps this change should be documented in CHANGES, and in the man
page (where enable-bracketed-paste is said to have the default value
Off).
The manual page in the released version will reflect the default setting
of bracketed paste. While it will probably remain on by default, there
have already been several reports of the bracketed paste enable/disable
escape sequences interfering with program-driven readline use cases, so
it's not certain it will.
FWIW, I've been using bash for twenty years (starting with version 2.05
IIRC), and it's the first time I see changes that I find disturbing and
want to turn off. The paste behavior with enable-bracketed-paste on also
disturbed me, but I wasn't sure how to explain it.
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Nice mottoes :-)