From 5e9a94b016b497d1743bc1b396293072d3bc6cde Mon Sep 17 00:00:00 2001
From: Tom Dalziel <tom_dl@hotmail.com>
Date: Mon, 22 Jul 2024 22:06:22 +0200
Subject: [PATCH] Allow `\l`, `\U`, etc. override case-replace in substitution
 replacements

---
 evil-commands.el | 10 ++++++++--
 evil-common.el   | 28 ++++++++++++++++------------
 2 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/evil-commands.el b/evil-commands.el
index cd8a66d6..ff81181a 100644
--- a/evil-commands.el
+++ b/evil-commands.el
@@ -3939,6 +3939,10 @@ replacements made or found."
                    nreplaced
                    (if (/= nreplaced 1) "s" ""))))))
 
+(defvar evil--substitute-fixed-case (not case-replace)
+  "Whether the replacement for a substitution respects case.
+By default, the oposite of `case-replace', but can be overridden by flags.")
+
 (evil-define-operator evil-ex-substitute
   (beg end pattern replacement flags)
   "The Ex substitute command.
@@ -4014,7 +4018,8 @@ replacements made or found."
                           (when (member response '(?y ?a ?l))
                             (unless count-only
                               (set-match-data match-data)
-                              (replace-match next-replacement (not case-replace)))
+                              (replace-match next-replacement evil--substitute-fixed-case)
+                              (setq evil--substitute-fixed-case (not case-replace)))
                             (cl-incf nreplaced)
                             (evil-ex-hl-set-region
                              'evil-ex-substitute
@@ -4032,7 +4037,8 @@ replacements made or found."
                            (if (stringp replacement) replacement
                              (funcall (car replacement) (cdr replacement) nreplaced))))
                       (set-match-data match-data)
-                      (replace-match next-replacement (not case-replace))))
+                      (replace-match next-replacement evil--substitute-fixed-case)
+                      (setq evil--substitute-fixed-case (not case-replace))))
                   (cl-incf nreplaced))
                 (setq last-point (point))
                 (cond ((>= (point) end-marker)
diff --git a/evil-common.el b/evil-common.el
index 7f60bdfb..78659d4d 100644
--- a/evil-common.el
+++ b/evil-common.el
@@ -3524,6 +3524,7 @@ transformations, usually `regexp-quote' or `replace-quote'."
           (evil-magic evil-magic)
           (quote (or quote #'identity))
           result stop)
+      (setq evil--substitute-fixed-case (not case-replace))
       (while (and (not stop) str (string-match regexp str))
         (unless (zerop (match-beginning 1))
           (push (substring str 0 (match-beginning 1)) result))
@@ -3687,10 +3688,12 @@ REST is the unparsed remainder of TO."
                                           (?u . evil-upcase-first)
                                           (?U . upcase))))))
                   (list `(,func
-                          (replace-quote
-                           (evil-match-substitute-replacement
-                            ,(car result)
-                            (not case-replace))))
+                          (progn
+                            (setq evil--substitute-fixed-case t)
+                            (replace-quote
+                             (evil-match-substitute-replacement
+                              ,(car result)
+                              nil))))
                         (cdr result))))
                ((eq char ?=)
                 (when (or (zerop (length rest))
@@ -3733,7 +3736,7 @@ REST is the unparsed remainder of TO."
 Return a list suitable for `perform-replace' if necessary, the
 original string if not. Currently the following magic characters
 in replacements are supported: 0-9&#lLuUrnbt,
-The magic character , (comma) start an Emacs-lisp expression."
+The magic character , (comma) starts an Emacs-lisp expression."
   (when (stringp to)
     (save-match-data
       (cons 'replace-eval-replacement
@@ -3743,13 +3746,14 @@ The magic character , (comma) start an Emacs-lisp expression."
   "Return REPLACEMENT as it will be inserted by `evil-replace-match'.
 If REPLACEMENT is an expression it will be evaluated to compute the
 replacement text first."
-  (match-substitute-replacement
-   (if (stringp replacement)
-       replacement
-     (funcall (car replacement)
-              (cdr replacement)
-              0))
-   fixedcase nil string))
+  (cl-flet ((f-replacement () (funcall (car replacement)
+                                       (cdr replacement)
+                                       0)))
+    (match-substitute-replacement
+     (if (stringp replacement) replacement (f-replacement))
+     (or evil--substitute-fixed-case fixedcase)
+     nil
+     string)))
 
 ;;; Alignment