From ce28a67e28591987e9ca0a13ada4710e8950ffb4 Mon Sep 17 00:00:00 2001
From: Kazu Yamamoto <kazu@iij.ad.jp>
Date: Wed, 14 May 2014 05:05:49 +0900
Subject: [PATCH] checking if the buffer exists (#256).

---
 elisp/ghc-check.el   | 8 ++++----
 elisp/ghc-func.el    | 8 ++++++++
 elisp/ghc-process.el | 6 +++---
 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/elisp/ghc-check.el b/elisp/ghc-check.el
index aa5170b..975be72 100644
--- a/elisp/ghc-check.el
+++ b/elisp/ghc-check.el
@@ -80,9 +80,9 @@ nil            does not display errors/warnings.
 	      (buf ghc-process-original-buffer))
 	  (ghc-check-highlight-original-buffer file buf infos)))
        (t
-	(with-current-buffer ghc-process-original-buffer
+	(ghc-with-current-buffer ghc-process-original-buffer
 	  (remove-overlays (point-min) (point-max) 'ghc-check t))))
-      (with-current-buffer ghc-process-original-buffer
+      (ghc-with-current-buffer ghc-process-original-buffer
 	(let ((len (length infos)))
 	  (if (= len 0)
 	      (setq mode-line-process "")
@@ -91,7 +91,7 @@ nil            does not display errors/warnings.
 		   (wlen (- len elen)))
 	      (setq mode-line-process (format " %d:%d" elen wlen))))))))
    (t
-    (with-current-buffer ghc-process-original-buffer
+    (ghc-with-current-buffer ghc-process-original-buffer
       (setq mode-line-process " failed")))))
 
 (defun ghc-to-info (errs)
@@ -114,7 +114,7 @@ nil            does not display errors/warnings.
 	    (ghc-add infos info)))))))
 
 (defun ghc-check-highlight-original-buffer (ofile buf infos)
-  (with-current-buffer buf
+  (ghc-with-current-buffer buf
     (remove-overlays (point-min) (point-max) 'ghc-check t)
     (save-excursion
       (goto-char (point-min))
diff --git a/elisp/ghc-func.el b/elisp/ghc-func.el
index 7884783..9fe7d69 100644
--- a/elisp/ghc-func.el
+++ b/elisp/ghc-func.el
@@ -205,4 +205,12 @@
 	expr
       (concat "(" expr ")"))))
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(defmacro ghc-with-current-buffer (buf &rest body)
+  ;; (declare (indent 1))
+  `(if (get-buffer ,buf)
+       (with-current-buffer ,buf
+	 ,@body)))
+
 (provide 'ghc-func)
diff --git a/elisp/ghc-process.el b/elisp/ghc-process.el
index a686eb4..2d2dffc 100644
--- a/elisp/ghc-process.el
+++ b/elisp/ghc-process.el
@@ -36,7 +36,7 @@
 	   (buf (get-buffer-create (concat " ghc-modi:" name)))
 	   (file (buffer-file-name))
 	   (cpro (get-process name)))
-      (with-current-buffer buf
+      (ghc-with-current-buffer buf
 	(unless ghc-process-running
 	  (setq ghc-process-running t)
 	  (setq ghc-process-original-buffer cbuf)
@@ -69,7 +69,7 @@
     pro))
 
 (defun ghc-process-filter (process string)
-  (with-current-buffer (process-buffer process)
+  (ghc-with-current-buffer (process-buffer process)
     (goto-char (point-max))
     (insert string)
     (forward-line -1)
@@ -110,7 +110,7 @@
 	  ;; (discard-input) avoids getting stuck.
 	  (discard-input))
       (quit
-       (with-current-buffer (process-buffer pro)
+       (ghc-with-current-buffer (process-buffer pro)
 	 (setq ghc-process-running nil)))))
   ghc-process-results)