Avoid crashes when casifying noncontiguous regions

This is a followon fix for Bug#37477.
* lisp/simple.el (region-extract-function):
Use setq here, since the var is now defined in C code.
* src/casefiddle.c (casify_pnc_region): New function.
(Fupcase_region, Fdowncase_region, Fcapitalize_region)
(Fupcase_initials_region): Use it.
(Fupcase_initials_region): Add region-noncontiguous-p flag
for consistency with the others.  All uses changed.
(syms_of_casefiddle): Define Qbounds, Vregion_extract_function.
* src/insdel.c (prepare_to_modify_buffer_1):
* src/keyboard.c (command_loop_1):
Use Vregion_extraction_function.
* src/insdel.c (syms_of_insdel): No need to define
Qregion_extract_function.
* test/src/casefiddle-tests.el (casefiddle-oldfunc): New var.
(casefiddle-loopfunc, casefiddle-badfunc): New functions.
(casefiddle-invalid-region-extract-function): New test.

1 files changed, 2 insertions, 1 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 8a880e5b63a..73f0ca2497b 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -488,7 +488,8 @@ interface that's more like functions like 'search-forward'.
 ---
 ** More commands support noncontiguous rectangular regions, namely
 'upcase-dwim', 'downcase-dwim', 'capitalize-dwim', 'capitalize-region',
-'replace-string', 'replace-regexp', and 'delimit-columns-region'.
+'upcase-initials-region', 'replace-string', 'replace-regexp', and
+'delimit-columns-region'.
 
 +++
 ** When asked to visit a large file, Emacs now offers visiting it literally.