[PATCH for comments] configure: install a whitespace checking pre-commit hook for developers

[Ralph Böhme]

On Tue, Apr 10, 2018 at 08:20:55AM +0200, Ralph Böhme via samba-technical wrote:
> On Tue, Apr 10, 2018 at 12:35:07AM +1200, Douglas Bagnall via samba-technical wrote:
> > Martin wrote:
> > 
> > > The problem is that the *initial* proposal is not for a checkpatch
> > > script that people can run *before* submitting their patch.  The
> > > proposal is for something that runs at the submission gate.
> > 
> > This patch shows a third way, still quite authoritarian but sort of
> > opt-out-able and entirely local. It makes it harder to *create*
> > patches that break the rules, not to submit them.
> > 
> > It will also (I think) make it harder to `git am` a patch series that
> > contains whitespace errors, and will possibly annoy people who make a
> > lot of private WIP patches.
> 
> [slow at kazak scratch]$ git am ~/patches/0001-configure-install-a-whitespace-checking-pre-commit-h.patch
> Applying: configure: install a whitespace checking pre-commit hook for developers
> .git/rebase-apply/patch:46: trailing whitespace.
>         # simple default.
> warning: 1 line adds whitespace errors.
> [slow at kazak scratch]$
> 
> :)))

besides that, this is really, really nice. Thanks Douglas!

Updated patch with fixed whitespace attached.

-slow

-- 
Ralph Boehme, Samba Team       https://samba.org/
Samba Developer, SerNet GmbH   https://sernet.de/en/samba/
GPG Key Fingerprint:           FAE2 C608 8A24 2520 51C5
                               59E4 AA1E 9B71 2639 9E46
-------------- next part --------------
From b52690ded76b0d09847f44b6ec29e4c8f741c9b6 Mon Sep 17 00:00:00 2001
From: Douglas Bagnall <douglas.bagnall at catalyst.net.nz>
Date: Tue, 10 Apr 2018 00:03:55 +1200
Subject: [PATCH] configure: install a whitespace checking pre-commit hook for
 developers

If you don't already have a pre-commit git hook,

  configure --enable-developer

will give you one that checks for whitespace errors in changed lines
of Python, Perl and C.

Signed-off-by: Douglas Bagnall <douglas.bagnall at catalyst.net.nz>
Reviewed-by: Ralph Boehme <slow at samba.org>
---
 examples/git-hooks/pre-commit | 15 +++++++++++++++
 wscript                       |  9 ++++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)
 create mode 100755 examples/git-hooks/pre-commit

diff --git a/examples/git-hooks/pre-commit b/examples/git-hooks/pre-commit
new file mode 100755
index 00000000000..68c6150cde6
--- /dev/null
+++ b/examples/git-hooks/pre-commit
@@ -0,0 +1,15 @@
+#!/bin/sh
+
+git diff-index --check  HEAD -- :/*.[ch] :/*.p[ylm]
+
+if [ $? != 0 ]; then
+    echo
+    echo "The commit failed because it seems to introduce trailing whitespace"
+    echo "into C, Perl, or Python code."
+    echo
+    echo "If you are sure you want to do this, repeat the commit with the "
+    echo "--no-verify, like this:"
+    echo
+    echo "   git commit --no-verify"
+    exit 1
+fi
diff --git a/wscript b/wscript
index 0985aa94867..ce0b6f91e6e 100644
--- a/wscript
+++ b/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')
@@ -105,6 +105,13 @@ default_prefix = Options.default_prefix = '/usr/local/samba'
     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, 'examples/git-hooks/pre-commit'),
+                        pre_commit_hook)
 
     conf.ADD_EXTRA_INCLUDES('#include/public #source4 #lib #source4/lib #source4/include #include #lib/replace')
 
-- 
2.13.6