diff --git a/doc/emacs/custom.texi b/doc/emacs/custom.texi
index c1093353757..771633623f5 100644
--- a/doc/emacs/custom.texi
+++ b/doc/emacs/custom.texi
@@ -1396,7 +1396,7 @@ init file (@pxref{Init Rebinding}).
 * Minibuffer Maps::     The minibuffer uses its own local keymaps.
 * Rebinding::           How to redefine one key's meaning conveniently.
 * Init Rebinding::      Rebinding keys with your initialization file.
-* Modifier Keys::       Using modifier keys in key bindings.
+* Modifier Keys::       Using modifier keys.
 * Function Keys::       Rebinding terminal function keys.
 * Named ASCII Chars::   Distinguishing @key{TAB} from @kbd{C-i}, and so on.
 * Mouse Buttons::       Rebinding mouse buttons in Emacs.
diff --git a/lisp/calendar/icalendar.el b/lisp/calendar/icalendar.el
index 386c554c068..c88f4abcb6e 100644
--- a/lisp/calendar/icalendar.el
+++ b/lisp/calendar/icalendar.el
@@ -361,7 +361,8 @@ Pass arguments REGEXP REP STRING FIXEDCASE LITERAL to
 INVALUE gives the current iCalendar element we are reading.
 INPARAMS gives the current parameters.....
 This function calls itself recursively for each nested calendar element
-it finds."
+it finds.  The current buffer should be an unfolded buffer as returned
+from `icalendar--get-unfolded-buffer'."
   (let (element children line name params param param-name param-value
                 value
                 (continue t))
@@ -391,8 +392,9 @@ it finds."
       (unless (looking-at ":")
         (error "Oops"))
       (forward-char 1)
-      (re-search-forward  "\\(.*\\)\\(\r?\n[ \t].*\\)*" nil t)
-      (setq value (icalendar--rris "\r?\n[ \t]" "" (match-string 0)))
+      (let ((start (point)))
+        (end-of-line)
+        (setq value (buffer-substring start (point))))
       (setq line (list name params value))
       (cond ((eq name 'BEGIN)
              (setq children
diff --git a/lisp/isearch.el b/lisp/isearch.el
index a97247671cc..9df7627fa7c 100644
--- a/lisp/isearch.el
+++ b/lisp/isearch.el
@@ -1049,9 +1049,10 @@ NOPUSH is t and EDIT is t."
   (remove-hook 'mouse-leave-buffer-hook 'isearch-done)
   (remove-hook 'kbd-macro-termination-hook 'isearch-done)
   (setq isearch-lazy-highlight-start nil)
-  (with-current-buffer isearch--current-buffer
-    (setq isearch--current-buffer nil)
-    (setq cursor-sensor-inhibit (delq 'isearch cursor-sensor-inhibit)))
+  (when (buffer-live-p isearch--current-buffer)
+    (with-current-buffer isearch--current-buffer
+      (setq isearch--current-buffer nil)
+      (setq cursor-sensor-inhibit (delq 'isearch cursor-sensor-inhibit))))
 
   ;; Called by all commands that terminate isearch-mode.
   ;; If NOPUSH is non-nil, we don't push the string on the search ring.
diff --git a/lisp/url/url-http.el b/lisp/url/url-http.el
index 8f36ddeafbf..e0e080e76af 100644
--- a/lisp/url/url-http.el
+++ b/lisp/url/url-http.el
@@ -1195,17 +1195,20 @@ the end of the document."
   "Retrieve URL via HTTP asynchronously.
 URL must be a parsed URL.  See `url-generic-parse-url' for details.
 
-When retrieval is completed, execute the function CALLBACK, passing it
-an updated value of CBARGS as arguments.  The first element in CBARGS
-should be a plist describing what has happened so far during the
-request, as described in the docstring of `url-retrieve' (if in
-doubt, specify nil).
+When retrieval is completed, execute the function CALLBACK,
+passing it an updated value of CBARGS as arguments.  The first
+element in CBARGS should be a plist describing what has happened
+so far during the request, as described in the docstring of
+`url-retrieve' (if in doubt, specify nil).  The current buffer
+then CALLBACK is executed is the retrieval buffer.
 
 Optional arg RETRY-BUFFER, if non-nil, specifies the buffer of a
 previous `url-http' call, which is being re-attempted.
 
 Optional arg GATEWAY-METHOD specifies the gateway to be used,
-overriding the value of `url-gateway-method'."
+overriding the value of `url-gateway-method'.
+
+The return value of this function is the retrieval buffer."
   (cl-check-type url vector "Need a pre-parsed URL.")
   (let* ((host (url-host (or url-using-proxy url)))
 	 (port (url-port (or url-using-proxy url)))
diff --git a/test/automated/isearch-tests.el b/test/automated/isearch-tests.el
index 48c342403c9..52f312d0b97 100644
--- a/test/automated/isearch-tests.el
+++ b/test/automated/isearch-tests.el
@@ -28,5 +28,13 @@
     (isearch-update)
     (should (equal isearch--current-buffer (current-buffer)))))
 
+(ert-deftest isearch--test-done ()
+  ;; Normal operation.
+  (isearch-update)
+  (isearch-done)
+  (should-not isearch--current-buffer)
+  ;; Bug #21091: let `isearch-done' work without `isearch-update'.
+  (isearch-done))
+
 (provide 'isearch-tests)
 ;;; isearch-tests.el ends here