slurp: Reduce new line stretches to single space

... instead of replacing each new line with a space.

org-link-edit.el

@@ -155,7 +155,7 @@ If N is negative, slurp leading blobs instead of trailing blobs."
                        (user-error "Not enough blobs after the link"))
                    (point)))
       (let ((slurped (buffer-substring-no-properties end (point))))
-        (setq slurped (replace-regexp-in-string "\n" " " slurped))
+        (setq slurped (replace-regexp-in-string "\n+" " " slurped))
         (when (and (= (length desc) 0)
                    (string-match "^\\s-+\\(.*\\)" slurped))
           (setq slurped (match-string 1 slurped)))
@@ -200,7 +200,7 @@ If N is negative, slurp trailing blobs instead of leading blobs."
         (when (and (= (length desc) 0)
                    (string-match "\\(.*\\)\\s-+$" slurped))
           (setq slurped (match-string 1 slurped)))
-        (setq slurped (replace-regexp-in-string "\n" " " slurped))
+        (setq slurped (replace-regexp-in-string "\n+" " " slurped))
         (setq desc (concat slurped desc)
               beg (- beg (length slurped)))
         (delete-region (point) end)

test-org-link-edit.el

@@ -113,6 +113,15 @@ otherwise place the point at the beginning of the inserted text."
 website is"
       (org-link-edit-forward-slurp 1)
       (buffer-string))))
+  ;; Collapse stretches of new lines.
+  (should
+   (string=
+    "\[\[http://orgmode.org/\]\[Org's website is\]\]"
+    (org-test-with-temp-text
+        "\[\[http://orgmode.org/\]\[Org's\]\]
+\n\nwebsite\n\n\nis"
+      (org-link-edit-forward-slurp 2)
+      (buffer-string))))
   ;; Slurp blob that has no whitespace.
   (should
    (string=
@@ -204,6 +213,15 @@ website is"
 <point>\[\[http://orgmode.org/\]\[Org's website\]\]"
       (org-link-edit-backward-slurp 1)
       (buffer-string))))
+  ;; Collapse stretches of new lines.
+  (should
+   (string=
+    "\[\[http://orgmode.org/\]\[Here is Org's website\]\]"
+    (org-test-with-temp-text
+        "Here\n\nis\n\n\n
+<point>\[\[http://orgmode.org/\]\[Org's website\]\]"
+      (org-link-edit-backward-slurp 2)
+      (buffer-string))))
   ;; Slurp blob that has no whitespace.
   (should
    (string=