Support rectangular regions in capitalize-region and capitalize-dwim.

* lisp/simple.el (capitalize-dwim): Add arg region-noncontiguous-p
in capitalize-region call.

* src/casefiddle.c (Fcapitalize_region): Add arg region-noncontiguous-p.
If non-nil, operate on multiple chunks.  (Bug#37477)
(Fdowncase_region): Use builtin symbol Qregion_extract_function
rather than calling intern.

3 files changed, 23 insertions, 7 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 6a4a6e60d4d..20d2e62bd3b 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -487,8 +487,8 @@ interface that's more like functions like 'search-forward'.
 
 ---
 ** More commands support noncontiguous rectangular regions, namely
-'upcase-dwim', 'downcase-dwim', 'replace-string', 'replace-regexp',
-and 'delimit-columns-region'.
+'upcase-dwim', 'downcase-dwim', 'capitalize-dwim', 'capitalize-region',
+'replace-string', 'replace-regexp', and 'delimit-columns-region'.
 
 +++
 ** When asked to visit a large file, Emacs now offers visiting it literally.
diff --git a/lisp/simple.el b/lisp/simple.el
index a267200aeb9..31e3b2bbaba 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -9074,7 +9074,7 @@ Otherwise, it calls `capitalize-word', with prefix argument passed to it
 to capitalize ARG words."
   (interactive "*p")
   (if (use-region-p)
-      (capitalize-region (region-beginning) (region-end))
+      (capitalize-region (region-beginning) (region-end) (region-noncontiguous-p))
     (capitalize-word arg)))
 
 ;;; Accessors for `decode-time' values.
diff --git a/src/casefiddle.c b/src/casefiddle.c
index ee292dda9b3..3a1724b306d 100644
--- a/src/casefiddle.c
+++ b/src/casefiddle.c
@@ -556,7 +556,7 @@ point and the mark is operated on.  */)
 
   if (!NILP (region_noncontiguous_p))
     {
-      bounds = call1 (Fsymbol_value (intern ("region-extract-function")),
+      bounds = call1 (Fsymbol_value (Qregion_extract_function),
                       intern ("bounds"));
 
       while (CONSP (bounds))
@@ -571,15 +571,31 @@ point and the mark is operated on.  */)
   return Qnil;
 }
 
-DEFUN ("capitalize-region", Fcapitalize_region, Scapitalize_region, 2, 2, "r",
+DEFUN ("capitalize-region", Fcapitalize_region, Scapitalize_region, 2, 3,
+       "(list (region-beginning) (region-end) (region-noncontiguous-p))",
        doc: /* Convert the region to capitalized form.
 This means that each word's first character is converted to either
 title case or upper case, and the rest to lower case.
 In programs, give two arguments, the starting and ending
 character positions to operate on.  */)
-  (Lisp_Object beg, Lisp_Object end)
+  (Lisp_Object beg, Lisp_Object end, Lisp_Object region_noncontiguous_p)
 {
-  casify_region (CASE_CAPITALIZE, beg, end);
+  Lisp_Object bounds = Qnil;
+
+  if (!NILP (region_noncontiguous_p))
+    {
+      bounds = call1 (Fsymbol_value (Qregion_extract_function),
+                      intern ("bounds"));
+
+      while (CONSP (bounds))
+        {
+          casify_region (CASE_CAPITALIZE, XCAR (XCAR (bounds)), XCDR (XCAR (bounds)));
+          bounds = XCDR (bounds);
+        }
+    }
+  else
+    casify_region (CASE_CAPITALIZE, beg, end);
+
   return Qnil;
 }