Add hack to support git 1.6 in git_version.sh

This is needed now for people who are running the "master" branch of
git, which is currently in development for git version 1.6.0.

This is a kludge to support hyphenated git commands (i.e.,
git-diff-files), but this form is explicitly deprecated, and doesn't
work in git 1.6 unless you put git's execdir (obtained via git
--exec-path) in your PATH environment variable.  Even then, these
programs may no longer exist future versions of git.  It would be
better to change the script to use "git diff-files", et. al., but I
assume upstream had some vaguely justifiable reason for not writing
the script that way.  I'll let them decide when they are willing to
fix the script the right way, even if it means breaking compatibility
for some ancient version of git.  n.b., git 1.5.0 was released
February 2007, and git 1.4.0 was released June, 2006.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 23 insertions, 0 deletions

diff --git a/git_version.sh b/git_version.sh
index 5cf29437..50658970 100755
--- a/git_version.sh
+++ b/git_version.sh
@@ -155,6 +155,29 @@ cat<<EOF
 
 EOF
 
+# Backwards compatibility hack for git 1.6.0 (and people running the
+# latest pre-release version of git.) 
+#
+# For now, we'll do this to support git 1.6, with minimal changes to
+# the rest of this script, but no guarantees how long this will work.
+# The hyphenated git-foo-bar names really are deprecated, and may
+# disappear in the future as more of git gets rewritten as built-in C
+# programs.  Google summer of code students and other git developers
+# are hard at work doing this, in order to make git more
+# portable/usable for Windows users.  As a result, some of the
+# git-foo-bar programs, which will be moved to the exec-dir directory
+# in git 1.6, may disappear altogether in the future.  Hence the only
+# truly safe and future-compatible way of running commands such as
+# git-diff-files, git-rev-parse, etc., are "git diff-files" and 
+# "git rev-parse".  Here endeth the git portability sermon, which
+# I suspect will have as much effect as abstinence-only sex ed 
+# classes.  :-)   TYT, 2008-07-08
+
+execdir=$(git --exec-path 2> /dev/null)
+if test -n "$execdir"; then
+    PATH=$PATH:$execdir
+fi
+
 # Detect git tools (should work with old and new git versions)
 git_found=yes
 for git_tool in git-symbolic-ref git-rev-parse git-diff-files git-diff-index git