Create a sysconfdir variable, and use it for ETC_GITCONFIG

ETC_GITCONFIG defaults to $(prefix)/etc/gitconfig, so if you just set
prefix=/usr, you end up with a git that looks in /usr/etc/gitconfig, rather
than /etc/gitconfig as specified by the FHS.  Furthermore, setting
ETC_GITCONFIG does not fix the paths to any future system-wide configuration
files.

Factor out the path to the system-wide configuration directory into a variable
sysconfdir, normally set to $(prefix)/etc, but set to /etc when prefix=/usr .
This fixes the prefix=/usr problem for ETC_GITCONFIG, and allows centralized
configuration of any future system-wide configuration files without requiring
further action from package maintainers or other people building and
installing git.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Makefile

@@ -133,7 +133,12 @@ prefix = $(HOME)
 bindir = $(prefix)/bin
 gitexecdir = $(bindir)
 template_dir = $(prefix)/share/git-core/templates/
-ETC_GITCONFIG = $(prefix)/etc/gitconfig
+ifeq ($(prefix),/usr)
+sysconfdir = /etc
+else
+sysconfdir = $(prefix)/etc
+endif
+ETC_GITCONFIG = $(sysconfdir)/gitconfig
 # DESTDIR=
 
 # default configuration for gitweb
@@ -152,7 +157,7 @@ GITWEB_FAVICON = git-favicon.png
 GITWEB_SITE_HEADER =
 GITWEB_SITE_FOOTER =
 
-export prefix bindir gitexecdir template_dir
+export prefix bindir gitexecdir template_dir sysconfdir
 
 CC = gcc
 AR = ar