bug#37766: 26.1; M-x find-name-dired plus wdired mangles whitespaces

[Diogo F. S. Ramos]

If I rename files in directories with whitespaces, a new directory
without whitespaces is created and this new directory has the new file.

For example, if I have

 bar baz/
 bar baz/qux

and try to rename "qux" to "quux", I get

 bar baz/
 barbaz/
 barbaz/quux

Recipe to reproduce it:

M-x make-directory /tmp/foo/bar baz RET
C-x C-f /tmp/foo/bar baz/qux RET
C-x C-s
M-x find-name-dired RET /tmp/foo RET qux RET
C-x C-q
Change "qux" to "quux"
C-c C-c