emacs: Refactor subprocess stderr propagation

Load subprocess error output to a string in the callers, and propagate
the error messages as a string parameter instead of a path to file
names.

Required to be able to avoid using temporary files for subprocess
error output.

* notmuch-lib.el: Update notmuch-check-async-exit-status,
  notmuch-check-exit-status: accept an err parameter instead of
  err-file; shift the responsibility of loading error messages from
  files up the call stack.

diff --git a/emacs/notmuch-lib.el b/emacs/notmuch-lib.el
index 337b20ace74f36b91b5ce76614f7fc3552a54ac5..1f743eff7f1abf5e036a7be5e8c972af6169df16 100644 (file)
--- a/emacs/notmuch-lib.el
+++ b/emacs/notmuch-lib.el
@@ -768,23 +768,23 @@ signaled error.  This function does not return."
   (error "%s" (concat msg (when extra
                            " (see *Notmuch errors* for more details)"))))
 
-(defun notmuch-check-async-exit-status (proc msg &optional command err-file)
+(defun notmuch-check-async-exit-status (proc msg &optional command err)
   "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.  COMMAND and ERR-FILE, if
-provided, are passed to `notmuch-check-exit-status'.  If COMMAND
-is not provided, it is taken from `process-command'."
+arguments passed to the sentinel.  COMMAND and ERR, if provided,
+are passed to `notmuch-check-exit-status'.  If COMMAND is not
+provided, it is taken from `process-command'."
   (let ((exit-status
         (case (process-status proc)
           ((exit) (process-exit-status proc))
           ((signal) msg))))
     (when exit-status
       (notmuch-check-exit-status exit-status (or command (process-command proc))
-                                nil err-file))))
+                                nil err))))
 
-(defun notmuch-check-exit-status (exit-status command &optional output err-file)
+(defun notmuch-check-exit-status (exit-status command &optional output err)
   "If EXIT-STATUS is non-zero, pop up an error buffer and signal an error.
 
 If EXIT-STATUS is non-zero, pop up a notmuch error buffer
@@ -793,9 +793,9 @@ be a number indicating the exit status code of a process or a
 string describing the signal that terminated the process (such as
 returned by `call-process').  COMMAND must be a list giving the
 command and its arguments.  OUTPUT, if provided, is a string
-giving the output of command.  ERR-FILE, if provided, is the name
-of a file containing the error output of command.  OUTPUT and the
-contents of ERR-FILE will be included in the error message."
+giving the output of command.  ERR, if provided, is the error
+output of command.  OUTPUT and ERR will be included in the error
+message."
 
   (cond
    ((eq exit-status 0) t)
@@ -808,12 +808,7 @@ You may need to restart Emacs or upgrade your notmuch Emacs package."))
 Emacs requested a newer output format than supported by the notmuch CLI.
 You may need to restart Emacs or upgrade your notmuch package."))
    (t
-    (let* ((err (when err-file
-                 (with-temp-buffer
-                   (insert-file-contents err-file)
-                   (unless (eobp)
-                     (buffer-string)))))
-          (command-string
+    (let* ((command-string
            (mapconcat (lambda (arg)
                         (shell-quote-argument
                          (cond ((stringp arg) arg)
@@ -889,9 +884,13 @@ error."
   (with-temp-buffer
     (let ((err-file (make-temp-file "nmerr")))
       (unwind-protect
-         (let ((status (notmuch-call-notmuch--helper (list t err-file) args)))
+         (let ((status (notmuch-call-notmuch--helper (list t err-file) args))
+               (err (with-temp-buffer
+                      (insert-file-contents err-file)
+                      (unless (eobp)
+                        (buffer-string)))))
            (notmuch-check-exit-status status (cons notmuch-command args)
-                                      (buffer-string) err-file)
+                                      (buffer-string) err)
            (goto-char (point-min))
            (read (current-buffer)))
        (delete-file err-file)))))
@@ -931,9 +930,14 @@ status."
     proc))
 
 (defun notmuch-start-notmuch-sentinel (proc event)
-  (let ((err-file (process-get proc 'err-file))
-       (sub-sentinel (process-get proc 'sub-sentinel))
-       (real-command (process-get proc 'real-command)))
+  "Process sentinel function used by `notmuch-start-notmuch'."
+  (let* ((err-file (process-get proc 'err-file))
+        (err (with-temp-buffer
+               (insert-file-contents err-file)
+               (unless (eobp)
+                 (buffer-string))))
+        (sub-sentinel (process-get proc 'sub-sentinel))
+        (real-command (process-get proc 'real-command)))
     (condition-case err
        (progn
          ;; Invoke the sub-sentinel, if any
@@ -945,12 +949,13 @@ status."
          ;; and there's no point in telling the user that (but we
          ;; still check for and report stderr output below).
          (when (buffer-live-p (process-buffer proc))
-           (notmuch-check-async-exit-status proc event real-command err-file))
+           (notmuch-check-async-exit-status proc event real-command err))
          ;; If that didn't signal an error, then any error output was
          ;; really warning output.  Show warnings, if any.
          (let ((warnings
                 (with-temp-buffer
                   (unless (= (second (insert-file-contents err-file)) 0)
+                    (goto-char (point-min))
                     (end-of-line)
                     ;; Show first line; stuff remaining lines in the
                     ;; errors buffer.