Git 2.12.3

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/RelNotes/2.12.3.txt

@@ -54,4 +54,11 @@ Fixes since v2.12.2
    turn revealed incorrect expectations the tests make. These tests
    have been updated.
 
+ * "git-shell" rejects a request to serve a repository whose name
+   begins with a dash, which makes it no longer possible to get it
+   confused into spawning service programs like "git-upload-pack" with
+   an option like "--help", which in turn would spawn an interactive
+   pager, instead of working with the repository user asked to access
+   (i.e. the one whose name is "--help").
+
 Also contains various documentation updates and code clean-ups.