Restrict replace-*-in-region to the bounds defined by caller

* lisp/subr.el (replace-string-in-region, replace-regexp-in-region):
Narrow to region before iterating over matches, instead of giving a
bound to the search functions.
* test/lisp/subr-tests.el (test-replace-string-in-region): Add
regression tests (bug#57733).

2 files changed, 51 insertions, 19 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index 686189e69b8..8769fec2b95 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -4219,15 +4219,17 @@ Comparisons and replacements are done with fixed case."
         (error "End after end of buffer"))
     (setq end (point-max)))
   (save-excursion
-    (let ((matches 0)
-          (case-fold-search nil))
-      (goto-char start)
-      (while (search-forward string end t)
-        (delete-region (match-beginning 0) (match-end 0))
-        (insert replacement)
-        (setq matches (1+ matches)))
-      (and (not (zerop matches))
-           matches))))
+    (goto-char start)
+    (save-restriction
+      (narrow-to-region start end)
+      (let ((matches 0)
+            (case-fold-search nil))
+        (while (search-forward string nil t)
+          (delete-region (match-beginning 0) (match-end 0))
+          (insert replacement)
+          (setq matches (1+ matches)))
+        (and (not (zerop matches))
+             matches)))))
 
 (defun replace-regexp-in-region (regexp replacement &optional start end)
   "Replace REGEXP with REPLACEMENT in the region from START to END.
@@ -4254,14 +4256,16 @@ REPLACEMENT can use the following special elements:
         (error "End after end of buffer"))
     (setq end (point-max)))
   (save-excursion
-    (let ((matches 0)
-          (case-fold-search nil))
-      (goto-char start)
-      (while (re-search-forward regexp end t)
-        (replace-match replacement t)
-        (setq matches (1+ matches)))
-      (and (not (zerop matches))
-           matches))))
+    (goto-char start)
+    (save-restriction
+      (narrow-to-region start end)
+      (let ((matches 0)
+            (case-fold-search nil))
+          (while (re-search-forward regexp nil t)
+          (replace-match replacement t)
+          (setq matches (1+ matches)))
+        (and (not (zerop matches))
+             matches)))))
 
 (defun yank-handle-font-lock-face-property (face start end)
   "If `font-lock-defaults' is nil, apply FACE as a `face' property.
diff --git a/test/lisp/subr-tests.el b/test/lisp/subr-tests.el
index 4310b7291ad..30117132101 100644
--- a/test/lisp/subr-tests.el
+++ b/test/lisp/subr-tests.el
@@ -968,7 +968,21 @@ See https://debbugs.gnu.org/cgi/bugreport.cgi?bug=19350."
     (insert "Foo bar zot foobar")
     (should (= (replace-string-in-region "Foo" "new" (point-min))
                1))
-    (should (equal (buffer-string) "new bar zot foobar"))))
+    (should (equal (buffer-string) "new bar zot foobar")))
+
+  (with-temp-buffer
+    (insert "foo bar baz")
+    (should (= (replace-string-in-region "ba" "quux corge grault" (point-min))
+               2))
+    (should (equal (buffer-string)
+                    "foo quux corge graultr quux corge graultz")))
+
+  (with-temp-buffer
+    (insert "foo bar bar")
+    (should (= (replace-string-in-region " bar" "" (point-min) 8)
+               1))
+    (should (equal (buffer-string)
+                    "foo bar"))))
 
 (ert-deftest test-replace-regexp-in-region ()
   (with-temp-buffer
@@ -991,7 +1005,21 @@ See https://debbugs.gnu.org/cgi/bugreport.cgi?bug=19350."
     (insert "Foo bar zot foobar")
     (should (= (replace-regexp-in-region "Fo+" "new" (point-min))
                1))
-    (should (equal (buffer-string) "new bar zot foobar"))))
+    (should (equal (buffer-string) "new bar zot foobar")))
+
+  (with-temp-buffer
+    (insert "foo bar baz")
+    (should (= (replace-regexp-in-region "ba." "quux corge grault" (point-min))
+               2))
+    (should (equal (buffer-string)
+                    "foo quux corge grault quux corge grault")))
+
+  (with-temp-buffer
+    (insert "foo bar bar")
+    (should (= (replace-regexp-in-region " bar" "" (point-min) 8)
+               1))
+    (should (equal (buffer-string)
+                    "foo bar"))))
 
 (ert-deftest test-with-existing-directory ()
   (let ((dir (make-temp-name "/tmp/not-exist-")))