Make erc-current-logfile work with explicit parameter

* lisp/erc/erc-log.el (erc-current-logfile): This function
apparently refers to buffer-local variables, so switch to the
buffer given before calculating the file name (bug#16111).

1 files changed, 13 insertions, 12 deletions

diff --git a/lisp/erc/erc-log.el b/lisp/erc/erc-log.el
index 1dd2e0aba49..584f566f049 100644
--- a/lisp/erc/erc-log.el
+++ b/lisp/erc/erc-log.el
@@ -344,18 +344,19 @@ If BUFFER is nil, the value of `current-buffer' is used.
 This is determined by `erc-generate-log-file-name-function'.
 The result is converted to lowercase, as IRC is case-insensitive"
   (unless buffer (setq buffer (current-buffer)))
-  (let ((target (or (buffer-name buffer) (erc-default-target)))
-	(nick (erc-current-nick))
-	(server erc-session-server)
-	(port erc-session-port))
-    (expand-file-name
-     (erc-log-standardize-name
-      (funcall erc-generate-log-file-name-function
-	       buffer target nick server port))
-     (if (functionp erc-log-channels-directory)
-	 (funcall erc-log-channels-directory
-		  buffer target nick server port)
-       erc-log-channels-directory))))
+  (with-current-buffer buffer
+    (let ((target (or (buffer-name buffer) (erc-default-target)))
+	  (nick (erc-current-nick))
+	  (server erc-session-server)
+	  (port erc-session-port))
+      (expand-file-name
+       (erc-log-standardize-name
+	(funcall erc-generate-log-file-name-function
+		 buffer target nick server port))
+       (if (functionp erc-log-channels-directory)
+	   (funcall erc-log-channels-directory
+		    buffer target nick server port)
+	 erc-log-channels-directory)))))
 
 (defun erc-generate-log-file-name-with-date (buffer &rest ignore)
   "This function computes a short log file name.