+This function combines FACE with any existing faces between START
+and END in OBJECT. Attributes specified by FACE take precedence
+over existing attributes unless BELOW is non-nil.
+
+OBJECT may be a string, a buffer, or nil (which means the current
+buffer). If object is a string, START and END are 0-based;
+otherwise they are buffer positions (integers or markers). FACE
+must be a face name (a symbol or string), a property list of face
+attributes, or a list of these. If START and/or END are omitted,
+they default to the beginning/end of OBJECT. For convenience
+when applied to strings, this returns OBJECT."
+ ;; A face property can have three forms: a face name (a string or
+ ;; symbol), a property list, or a list of these two forms. In the
+ ;; list case, the faces will be combined, with the earlier faces
+ ;; taking precedent. Here we canonicalize everything to list form
+ ;; to make it easy to combine.
+ (let ((pos (cond (start start)
+ ((stringp object) 0)
+ (t 1)))
+ (end (cond (end end)
+ ((stringp object) (length object))
+ (t (1+ (buffer-size object)))))
+ (face-list (notmuch-face-ensure-list-form face)))
+ (while (< pos end)
+ (let* ((cur (get-text-property pos 'face object))
+ (cur-list (notmuch-face-ensure-list-form cur))
+ (new (cond ((null cur-list) face)
+ (below (append cur-list face-list))
+ (t (append face-list cur-list))))
+ (next (next-single-property-change pos 'face object end)))
+ (put-text-property pos next 'face new object)
+ (setq pos next))))
+ object)
+
+(defun notmuch-map-text-property (start end prop func &optional object)
+ "Transform text property PROP using FUNC.
+
+Applies FUNC to each distinct value of the text property PROP
+between START and END of OBJECT, setting PROP to the value
+returned by FUNC."
+ (while (< start end)
+ (let ((value (get-text-property start prop object))
+ (next (next-single-property-change start prop object end)))
+ (put-text-property start next prop (funcall func value) object)
+ (setq start next))))
+
+(defun notmuch-logged-error (msg &optional extra)
+ "Log MSG and EXTRA to *Notmuch errors* and signal MSG.
+
+This logs MSG and EXTRA to the *Notmuch errors* buffer and
+signals MSG as an error. If EXTRA is non-nil, text referring the
+user to the *Notmuch errors* buffer will be appended to the
+signaled error. This function does not return."
+ (with-current-buffer (get-buffer-create "*Notmuch errors*")
+ (goto-char (point-max))
+ (unless (bobp)
+ (newline))
+ (save-excursion
+ (insert "[" (current-time-string) "]\n" msg)
+ (unless (bolp)
+ (newline))
+ (when extra
+ (insert extra)
+ (unless (bolp)
+ (newline)))))
+ (error "%s%s" msg (if extra " (see *Notmuch errors* for more details)" "")))
+
+(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, if provided,
+are passed to `notmuch-check-exit-status'. If COMMAND is not
+provided, it is taken from `process-command'."
+ (let ((exit-status
+ (cl-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))))
+
+(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
+describing the error and signal an Elisp error. EXIT-STATUS must
+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, if provided, is the error
+output of command. OUTPUT and ERR will be included in the error
+message."
+ (cond
+ ((eq exit-status 0) t)
+ ((eq exit-status 20)
+ (notmuch-logged-error "notmuch CLI version mismatch
+Emacs requested an older output format than supported by the notmuch CLI.
+You may need to restart Emacs or upgrade your notmuch Emacs package."))
+ ((eq exit-status 21)
+ (notmuch-logged-error "notmuch CLI version mismatch
+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* ((command-string
+ (mapconcat (lambda (arg)
+ (shell-quote-argument
+ (cond ((stringp arg) arg)
+ ((symbolp arg) (symbol-name arg))
+ (t "*UNKNOWN ARGUMENT*"))))
+ command " "))
+ (extra
+ (concat "command: " command-string "\n"
+ (if (integerp exit-status)
+ (format "exit status: %s\n" exit-status)
+ (format "exit signal: %s\n" exit-status))
+ (and err (concat "stderr:\n" err))
+ (and output (concat "stdout:\n" output)))))
+ (if err
+ ;; We have an error message straight from the CLI.
+ (notmuch-logged-error
+ (replace-regexp-in-string "[ \n\r\t\f]*\\'" "" err) extra)
+ ;; We only have combined output from the CLI; don't inundate
+ ;; the user with it. Mimic `process-lines'.
+ (notmuch-logged-error (format "%s exited with status %s"
+ (car command) exit-status)
+ extra))
+ ;; `notmuch-logged-error' does not return.
+ ))))
+
+(defun notmuch-call-notmuch--helper (destination args)
+ "Helper for synchronous notmuch invocation commands.
+
+This wraps `call-process'. DESTINATION has the same meaning as
+for `call-process'. ARGS is as described for
+`notmuch-call-notmuch-process'."
+ (let (stdin-string)
+ (while (keywordp (car args))
+ (cl-case (car args)
+ (:stdin-string (setq stdin-string (cadr args))
+ (setq args (cddr args)))
+ (otherwise
+ (error "Unknown keyword argument: %s" (car args)))))
+ (if (null stdin-string)
+ (apply #'call-process notmuch-command nil destination nil args)
+ (insert stdin-string)
+ (apply #'call-process-region (point-min) (point-max)
+ notmuch-command t destination nil args))))
+
+(defun notmuch-call-notmuch-process (&rest args)
+ "Synchronously invoke `notmuch-command' with ARGS.
+
+The caller may provide keyword arguments before ARGS. Currently
+supported keyword arguments are:
+
+ :stdin-string STRING - Write STRING to stdin
+
+If notmuch exits with a non-zero status, output from the process
+will appear in a buffer named \"*Notmuch errors*\" and an error
+will be signaled."
+ (with-temp-buffer
+ (let ((status (notmuch-call-notmuch--helper t args)))
+ (notmuch-check-exit-status status (cons notmuch-command args)
+ (buffer-string)))))
+
+(defun notmuch-call-notmuch-sexp (&rest args)
+ "Invoke `notmuch-command' with ARGS and return the parsed S-exp output.
+
+This is equivalent to `notmuch-call-notmuch-process', but parses
+notmuch's output as an S-expression and returns the parsed value.
+Like `notmuch-call-notmuch-process', if notmuch exits with a
+non-zero status, this will report its output and signal an
+error."
+ (with-temp-buffer
+ (let ((err-file (make-temp-file "nmerr")))
+ (unwind-protect
+ (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)
+ (goto-char (point-min))
+ (read (current-buffer)))
+ (delete-file err-file)))))
+
+(defun notmuch-start-notmuch (name buffer sentinel &rest args)
+ "Start and return an asynchronous notmuch command.
+
+This starts and returns an asynchronous process running
+`notmuch-command' with ARGS. The exit status is checked via
+`notmuch-check-async-exit-status'. Output written to stderr is
+redirected and displayed when the process exits (even if the
+process exits successfully). NAME and BUFFER are the same as in
+`start-process'. SENTINEL is a process sentinel function to call
+when the process exits, or nil for none. The caller must *not*
+invoke `set-process-sentinel' directly on the returned process,
+as that will interfere with the handling of stderr and the exit
+status."
+ (let (err-file err-buffer proc err-proc
+ ;; Find notmuch using Emacs' `exec-path'
+ (command (or (executable-find notmuch-command)
+ (error "Command not found: %s" notmuch-command))))
+ (if (fboundp 'make-process)
+ (progn
+ (setq err-buffer (generate-new-buffer " *notmuch-stderr*"))
+ ;; Emacs 25 and newer has `make-process', which allows
+ ;; redirecting stderr independently from stdout to a
+ ;; separate buffer. As this allows us to avoid using a
+ ;; temporary file and shell invocation, use it when
+ ;; available.
+ (setq proc (make-process
+ :name name
+ :buffer buffer
+ :command (cons command args)
+ :connection-type 'pipe
+ :stderr err-buffer))
+ (setq err-proc (get-buffer-process err-buffer))
+ (process-put proc 'err-buffer err-buffer)
+
+ (process-put err-proc 'err-file err-file)
+ (process-put err-proc 'err-buffer err-buffer)
+ (set-process-sentinel err-proc #'notmuch-start-notmuch-error-sentinel))
+ ;; On Emacs versions before 25, there is no way to capture
+ ;; stdout and stderr separately for asynchronous processes, or
+ ;; even to redirect stderr to a file, so we use a trivial shell
+ ;; wrapper to send stderr to a temporary file and clean things
+ ;; up in the sentinel.
+ (setq err-file (make-temp-file "nmerr"))
+ (let ((process-connection-type nil)) ;; Use a pipe
+ (setq proc (apply #'start-process name buffer
+ "/bin/sh" "-c"
+ "exec 2>\"$1\"; shift; exec \"$0\" \"$@\""
+ command err-file args)))
+ (process-put proc 'err-file err-file))
+ (process-put proc 'sub-sentinel sentinel)
+ (process-put proc 'real-command (cons notmuch-command args))
+ (set-process-sentinel proc #'notmuch-start-notmuch-sentinel)
+ proc))
+
+(defun notmuch-start-notmuch-sentinel (proc event)
+ "Process sentinel function used by `notmuch-start-notmuch'."
+ (let* ((err-file (process-get proc 'err-file))
+ (err-buffer (or (process-get proc 'err-buffer)
+ (find-file-noselect err-file)))
+ (err (and (not (zerop (buffer-size err-buffer)))
+ (with-current-buffer err-buffer (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
+ (when sub-sentinel
+ (funcall sub-sentinel proc event))
+ ;; Check the exit status. This will signal an error if the
+ ;; exit status is non-zero. Don't do this if the process
+ ;; buffer is dead since that means Emacs killed the process
+ ;; 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))
+ ;; If that didn't signal an error, then any error output was
+ ;; really warning output. Show warnings, if any.
+ (let ((warnings
+ (and err
+ (with-current-buffer err-buffer
+ (goto-char (point-min))
+ (end-of-line)
+ ;; Show first line; stuff remaining lines in the
+ ;; errors buffer.
+ (let ((l1 (buffer-substring (point-min) (point))))
+ (skip-chars-forward "\n")
+ (cons l1 (and (not (eobp))
+ (buffer-substring (point)
+ (point-max)))))))))
+ (when warnings
+ (notmuch-logged-error (car warnings) (cdr warnings)))))
+ (error
+ ;; Emacs behaves strangely if an error escapes from a sentinel,
+ ;; so turn errors into messages.
+ (message "%s" (error-message-string err))))
+ (when err-file (ignore-errors (delete-file err-file)))))
+
+(defun notmuch-start-notmuch-error-sentinel (proc event)
+ (let* ((err-file (process-get proc 'err-file))
+ ;; When `make-process' is available, use the error buffer
+ ;; associated with the process, otherwise the error file.
+ (err-buffer (or (process-get proc 'err-buffer)
+ (find-file-noselect err-file))))
+ (when err-buffer (kill-buffer err-buffer))))