emacs: Use unified error handling in search

This slightly changes the output of an existing test since we now
report non-zero exits with a pop-up buffer instead of at the end of
the search results.

emacs/notmuch-lib.el

@@ -334,6 +334,19 @@ the user dismisses it."
 	  (insert "\n"))))
     (pop-to-buffer buf)))
 
+(defun notmuch-check-async-exit-status (proc msg)
+  "If PROC exited abnormally, pop up an error buffer and signal an error.
+
+This is a wrapper around `notmuch-check-exit-status' for
+asynchronous process sentinels.  PROC and MSG must be the
+arguments passed to the sentinel."
+  (let ((exit-status
+	 (case (process-status proc)
+	   ((exit) (process-exit-status proc))
+	   ((signal) msg))))
+    (when exit-status
+      (notmuch-check-exit-status exit-status (process-command proc)))))
+
 (defun notmuch-check-exit-status (exit-status command &optional output err-file)
   "If EXIT-STATUS is non-zero, pop up an error buffer and signal an error.
 

emacs/notmuch.el

@@ -638,6 +638,7 @@ of the result."
 	(exit-status (process-exit-status proc))
 	(never-found-target-thread nil))
     (when (memq status '(exit signal))
+      (catch 'return
 	(kill-buffer (process-get proc 'parse-buf))
 	(if (buffer-live-p buffer)
 	    (with-current-buffer buffer
@@ -648,17 +649,19 @@ of the result."
 		  (if (eq status 'signal)
 		      (insert "Incomplete search results (search process was killed).\n"))
 		  (when (eq status 'exit)
-		    (insert "End of search results.")
+		    (insert "End of search results.\n")
-		    (unless (= exit-status 0)
+		    (condition-case nil
-		      (insert (format " (process returned %d)" exit-status)))
+			(notmuch-check-async-exit-status proc msg)
-		    (insert "\n")
+		      ;; Suppress the error signal since strange
+		      ;; things happen if a sentinel signals.
+		      (error (throw 'return nil)))
 		    (if (and atbob
 			     (not (string= notmuch-search-target-thread "found")))
 			(set 'never-found-target-thread t)))))
 	      (when (and never-found-target-thread
 		       notmuch-search-target-line)
 		  (goto-char (point-min))
-		  (forward-line (1- notmuch-search-target-line))))))))
+		  (forward-line (1- notmuch-search-target-line)))))))))
 
 (defcustom notmuch-search-line-faces '(("unread" :weight bold)
 				       ("flagged" :foreground "blue"))

test/emacs-large-search-buffer

@@ -36,7 +36,7 @@ test_emacs '(notmuch-search "--this-option-does-not-exist")
 cat <<EOF >EXPECTED
 Error: Unexpected output from notmuch search:
 Unrecognized option: --this-option-does-not-exist
-End of search results. (process returned 1)
+End of search results.
 EOF
 test_expect_equal_file OUTPUT EXPECTED