Fix some minor gravatar.el issues

For discussion, see the following thread:
https://lists.gnu.org/archive/html/emacs-devel/2019-07/msg00528.html
* lisp/image/gravatar.el (gravatar-hash): Trim leading and trailing
whitespace in given address, as per the Gravatar docs.
(gravatar-retrieve-synchronously): Silence call to
url-retrieve-synchronously for consistency with gravatar-retrieve.
(gravatar-retrieved): Only cache buffer on successful retrieval.
* test/lisp/image/gravatar-tests.el: New file.

1 files changed, 34 insertions, 0 deletions

diff --git a/test/lisp/image/gravatar-tests.el b/test/lisp/image/gravatar-tests.el
new file mode 100644
index 00000000000..e6239da0084
--- /dev/null
+++ b/test/lisp/image/gravatar-tests.el
@@ -0,0 +1,34 @@
+;;; gravatar-tests.el --- tests for gravatar.el -*- lexical-binding: t -*-
+
+;; Copyright (C) 2019 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+(require 'gravatar)
+
+(ert-deftest gravatar-hash ()
+  "Test `gravatar-hash'."
+  (should (equal (gravatar-hash "") "d41d8cd98f00b204e9800998ecf8427e"))
+  (let ((hash "acbd18db4cc2f85cedef654fccc4a4d8"))
+    (should (equal (gravatar-hash "foo") hash))
+    (should (equal (gravatar-hash "foo ") hash))
+    (should (equal (gravatar-hash " foo") hash))
+    (should (equal (gravatar-hash " foo ") hash))))
+
+;;; gravatar-tests.el ends here