Work around 2^16 buffer char limit

CHANGELOG.md

@@ -3,6 +3,12 @@
 All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog].
 
+## Unreleased
+### Bugs fixed
+* Apheleia experiences difficulty formatting buffers longer than 2^16
+  characters. Previously, the formatting operation would fail entirely
+  in this case. Now it works, albeit with degraded performance.
+
 ## 1.1.1 (released 2020-07-16)
 ### Formatters
 * New: [OCamlFormat](https://github.com/ocaml-ppx/ocamlformat) for

apheleia.el

@@ -293,7 +293,7 @@ provided that its exit status is 0."
                      (if (funcall
                           (or exit-status
                               (lambda (status)
-                                (= 0 status)))
+                                (= 0 (logand 255 status))))
                           (process-exit-status proc))
                          (when callback
                            (funcall callback stdout))
@@ -315,7 +315,11 @@ provided that its exit status is 0."
              (with-current-buffer stdin
                (buffer-string))))
           (process-send-eof apheleia--current-process))
-      (error (message "Failed to run %s: %s" name (error-message-string e))))))
+      (error
+       (unless (string-match-p
+                "process .+ no longer connected to pipe; closed it"
+                (error-message-string e))
+         (message "Failed to run %s: %s" name (error-message-string e)))))))
 
 (defun apheleia--write-region-silently
     (start end filename &optional