(Freplace_buffer_contents): Preserve markers more carefully

Use `replace_range` rather than `delete+insert`.

* src/insdel.c (replace_range): Allow NEW to specify a chunk
of buffer text.
* src/editfns.c (Freplace_buffer_contents): Use it.
* test/src/editfns-tests.el (replace-buffer-contents-1): Remove
incorrect check which happened to succeed because point was not
preserved carefully enough.  Make the replacement text share a bit
more content to make the test a bit more strict.
(editfns-tests--replace-region): Doesn't fail any more.

1 files changed, 9 insertions, 7 deletions

diff --git a/test/src/editfns-tests.el b/test/src/editfns-tests.el
index 09af179a180..c3f825c6149 100644
--- a/test/src/editfns-tests.el
+++ b/test/src/editfns-tests.el
@@ -280,23 +280,25 @@
 
 (ert-deftest replace-buffer-contents-1 ()
   (with-temp-buffer
-    (insert #("source" 2 4 (prop 7)))
+    (insert #("source " 2 4 (prop 7)))
     (let ((source (current-buffer)))
       (with-temp-buffer
         (insert "before dest after")
         (let ((marker (set-marker (make-marker) 14)))
           (save-restriction
-            (narrow-to-region 8 12)
-            (replace-buffer-contents source))
+            (narrow-to-region 8 13)
+            (goto-char 12)
+            (should (looking-at " \\'"))
+            (replace-buffer-contents source)
+            (should (looking-at " \\'")))
           (should (equal (marker-buffer marker) (current-buffer)))
           (should (equal (marker-position marker) 16)))
         (should (equal-including-properties
                  (buffer-string)
-                 #("before source after" 9 11 (prop 7))))
-        (should (equal (point) 9))))
+                 #("before source after" 9 11 (prop 7))))))
     (should (equal-including-properties
              (buffer-string)
-             #("source" 2 4 (prop 7))))))
+             #("source " 2 4 (prop 7))))))
 
 (ert-deftest replace-buffer-contents-2 ()
   (with-temp-buffer
@@ -332,7 +334,7 @@
               (replace-buffer-contents str-buf))))))))
 
 (ert-deftest editfns-tests--replace-region ()
-  :expected-result :failed
+  ;; :expected-result :failed
   (with-temp-buffer
     (insert "here is some text")
     (let ((m5n (copy-marker (+ (point-min) 5)))