Add function to read all entries in a group

Use that to extend xdg-desktop-read-file.  Also fix a bug where all
entries in all groups were read and returned by xdg-desktop-read-file.
* lisp/xdg.el (xdg-desktop-read-group): New function.
(xdg-desktop-read-file): Use it.
* test/data/xdg/malformed.desktop: New file.
* test/data/xdg/test.desktop: Add another section.
* test/lisp/xdg-tests.el (xdg-desktop-parsing): Test presence of a key
in another group.  Test reading a prescribed group.  Test detecting a
malformed key=value.

3 files changed, 18 insertions, 4 deletions

diff --git a/test/data/xdg/malformed.desktop b/test/data/xdg/malformed.desktop
new file mode 100644
index 00000000000..144a3f719d5
--- /dev/null
+++ b/test/data/xdg/malformed.desktop
@@ -0,0 +1,4 @@
+# unacceptable key=value format
+[Desktop Entry]
+Key=value
+aowef faoweif of
diff --git a/test/data/xdg/test.desktop b/test/data/xdg/test.desktop
index b6dda62774a..b848cef5b0f 100644
--- a/test/data/xdg/test.desktop
+++ b/test/data/xdg/test.desktop
@@ -1,3 +1,5 @@
 # this is a comment
 [Desktop Entry]
 Name=Test
+[Another Section]
+Exec=frobnicate
diff --git a/test/lisp/xdg-tests.el b/test/lisp/xdg-tests.el
index 59c850b07af..4822a05c1e4 100644
--- a/test/lisp/xdg-tests.el
+++ b/test/lisp/xdg-tests.el
@@ -32,12 +32,20 @@
 
 (ert-deftest xdg-desktop-parsing ()
   "Test `xdg-desktop-read-file' parsing of .desktop files."
-  (let ((tab (xdg-desktop-read-file
-              (expand-file-name "test.desktop" xdg-tests-data-dir))))
-    (should (equal (gethash "Name" tab) "Test")))
+  (let ((tab1 (xdg-desktop-read-file
+               (expand-file-name "test.desktop" xdg-tests-data-dir)))
+        (tab2 (xdg-desktop-read-file
+               (expand-file-name "test.desktop" xdg-tests-data-dir)
+               "Another Section")))
+    (should (equal (gethash "Name" tab1) "Test"))
+    (should (eq 'default (gethash "Exec" tab1 'default)))
+    (should (equal "frobnicate" (gethash "Exec" tab2))))
   (should-error
    (xdg-desktop-read-file
-    (expand-file-name "wrong.desktop" xdg-tests-data-dir))))
+    (expand-file-name "wrong.desktop" xdg-tests-data-dir)))
+  (should-error
+   (xdg-desktop-read-file
+    (expand-file-name "malformed.desktop" xdg-tests-data-dir))))
 
 (ert-deftest xdg-desktop-strings-type ()
   "Test desktop \"string(s)\" type: strings delimited by \";\"."