[BUG] org-compile-prefix-format regexp change breaks eval forms [9.4.6 (9.4.6-gf72a65)]

[Radon Rosborough]

Hello,

In commit 0260d2fcf603f30210e2b95d37727edd832c12e9 of 2021-04-26, the
regexp used in `org-agenda-prefix-format' was updated to use a
non-greedy regexp, in order to allow multiple %(expression) instances
in `org-agenda-prefix-format'. Unfortunately, this change breaks the
ability to use nested forms in %(expression) instances. For example, I
use the following setting for `org-agenda-prefix-format':

(setf (alist-get 'agenda org-agenda-prefix-format)
          "  %(format-time-string \"%a\" (org-get-deadline-time (point)))  ")

When running `org-agenda', I now receive the error
`org-compile-prefix-format: End of file during parsing'. This is
because of the updated regexp match, which stops at the first closing
parenthesis:

ELISP> myfmt
"  %(format-time-string \"%a\" (org-get-deadline-time (point)))  "
ELISP> (and (string-match "%\\(\\?\\)?\\([-+]?[0-9.]*\\)\\([
.;,:!?=|/<>]?\\)\\([cltseib]\\|(.+?)\\)" myfmt) (match-string 4
myfmt))
"(format-time-string \"%a\" (org-get-deadline-time (point)"

With the previous regexp, it works fine:

ELISP> (and (string-match "%\\(\\?\\)?\\([-+]?[0-9.]*\\)\\([
.;,:!?=|/<>]?\\)\\([cltseib]\\|(.+)\\)" myfmt) (match-string 4 myfmt))
"(format-time-string \"%a\" (org-get-deadline-time (point)))"

Thanks,
Radon Rosborough