Add a wrapper script as git pre-commit hook

When developer mode is enabled, the wrapper script
"script/git-hooks/pre-commit-hook" gets installed as

  .git/hooks/pre-commit

and calls "script/git-hooks/pre-commit-script".

This way we can later modify the "script/git-hooks/pre-commit-script"
without the need to ever change the installed commit hook itself.

Signed-off-by: Ralph Boehme <slow at samba.org>
Reviewed-by: Martin Schwenke <martin at meltin.net>
Reviewed-by: Jeremy Allison <jra at samba.org>

script/git-hooks/pre-commit-hook

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+set -eu
+
+gitdir=$(git rev-parse --show-toplevel)
+if [ $? -ne 0 ] ; then
+    echo "git rev-parse --show-toplevel failed"
+    exit 1
+fi
+
+if [ ! -f ${gitdir}/script/git-hooks/pre-commit-script ] ; then
+    exit 0
+fi
+
+${gitdir}/script/git-hooks/pre-commit-script || exit $?
+
+exit 0

script/git-hooks/pre-commit-script

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+set -eu
+
+#
+# make emacs/magit work, cf
+# https://github.com/magit/magit/issues/3419
+#
+unset GIT_LITERAL_PATHSPECS
+
+gitdir=$(git rev-parse --show-toplevel)
+if [ $? -ne 0 ] ; then
+    echo "git rev-parse --show-toplevel failed"
+    exit 1
+fi
+
+exit 0

wscript

@@ -10,7 +10,7 @@ import sys, os, tempfile
 sys.path.insert(0, srcdir+"/buildtools/wafsamba")
 import wafsamba, Options, samba_dist, samba_git, Scripting, Utils, samba_version
 import Logs, samba_utils
-
+import shutil
 
 samba_dist.DIST_DIRS('.')
 samba_dist.DIST_BLACKLIST('.gitignore .bzrignore source4/selftest/provisions')
@@ -106,6 +106,13 @@ def configure(conf):
     if Options.options.developer:
         conf.ADD_CFLAGS('-DDEVELOPER -DDEBUG_PASSWORD')
         conf.env.DEVELOPER = True
+        # if we are in a git tree without a pre-commit hook, install a
+        # simple default.
+        pre_commit_hook = os.path.join(srcdir, '.git/hooks/pre-commit')
+        if (os.path.isdir(os.path.dirname(pre_commit_hook)) and
+            not os.path.exists(pre_commit_hook)):
+            shutil.copy(os.path.join(srcdir, 'script/git-hooks/pre-commit-hook'),
+                        pre_commit_hook)
 
     conf.ADD_EXTRA_INCLUDES('#include/public #source4 #lib #source4/lib #source4/include #include #lib/replace')