Forestall "Selected deleted buffer" in url-http-generic-filter

* lisp/url/url-http.el (url-http-generic-filter): Check that
corresponding buffer is still live before using it (bug#49928).

1 files changed, 12 insertions, 11 deletions

diff --git a/lisp/url/url-http.el b/lisp/url/url-http.el
index e3c178630ae..ba13a17a8fc 100644
--- a/lisp/url/url-http.el
+++ b/lisp/url/url-http.el
@@ -1494,17 +1494,18 @@ The return value of this function is the retrieval buffer."
   ;; Sometimes we get a zero-length data chunk after the process has
   ;; been changed to 'free', which means it has no buffer associated
   ;; with it.  Do nothing if there is no buffer, or 0 length data.
-  (and (process-buffer proc)
-       (/= (length data) 0)
-       (with-current-buffer (process-buffer proc)
-	 (url-http-debug "Calling after change function `%s' for `%S'" url-http-after-change-function proc)
-	 (funcall url-http-after-change-function
-		  (point-max)
-		  (progn
-		    (goto-char (point-max))
-		    (insert data)
-		    (point-max))
-		  (length data)))))
+  (let ((b (process-buffer proc)))
+    (when (and (buffer-live-p b) (not (zerop (length data))))
+      (with-current-buffer b
+        (url-http-debug "Calling after change function `%s' for `%S'"
+                        url-http-after-change-function proc)
+        (funcall url-http-after-change-function
+                 (point-max)
+                 (progn
+                   (goto-char (point-max))
+                   (insert data)
+                   (point-max))
+                 (length data))))))
 
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 ;;; file-name-handler stuff from here on out