Clean up file-size-function

It is now called `byte-count-to-string-function', and used instead of
calling `file-size-human-readable' directly where appropriate.

* lisp/files.el (file-size-human-readable-iec): New.
(file-size-function): Rename to byte-count-to-string-function.  Better
default value.  Eliminate lambda.  Better default for custom choice.
Put in group `files'.  More descriptive doc string.  Move.
(out-of-memory-warning-percentage, warn-maybe-out-of-memory)
(get-free-disk-space):
* lisp/dired.el (dired-number-of-marked-files):
* lisp/url/url-http.el (url-http-simple-after-change-function)
(url-http-content-length-after-change-function):
Use byte-count-to-string-function.
* test/lisp/files-test.el (files-test-file-size-human-readable):
Test file-size-human-readable-iec.

1 files changed, 6 insertions, 1 deletions

diff --git a/test/lisp/files-tests.el b/test/lisp/files-tests.el
index df2c3f47ae0..ed23f7675cc 100644
--- a/test/lisp/files-tests.el
+++ b/test/lisp/files-tests.el
@@ -1280,7 +1280,12 @@ renaming only, rather than modified in-place."
   (should (equal (file-size-human-readable 4294967296 'iec " ") "4 GiB"))
   (should (equal (file-size-human-readable 10000 nil " " "bit") "9.8 kbit"))
   (should (equal (file-size-human-readable 10000 'si " " "bit") "10 kbit"))
-  (should (equal (file-size-human-readable 10000 'iec " " "bit") "9.8 Kibit")))
+  (should (equal (file-size-human-readable 10000 'iec " " "bit") "9.8 Kibit"))
+
+  (should (equal (file-size-human-readable-iec 0) "0 B"))
+  (should (equal (file-size-human-readable-iec 1) "1 B"))
+  (should (equal (file-size-human-readable-iec 9621) "9.4 KiB"))
+  (should (equal (file-size-human-readable-iec 72528034765) "67.5 GiB")))
 
 (ert-deftest files-test-magic-mode-alist-re-baseline ()
   "Test magic-mode-alist with RE, expected behaviour for match."