[PATCH 1/4] maint: Saner diff output

[Eric Blake]

Gnulib's bootstrap script is already set up to prefer the use of
git-merge-changelog as long as we hand-maintain that file (until we
follow through with the thread of switching to gnulib's
gitlog-to-changelog script to autogenerate ChangeLog from our git
history).

Meanwhile, providing some hints to git makes our diff output easier to
parse, with nicer chunk support for *.texi and with nicer overall
patch ordering.

* .gitattributes: New file.
* etc/git.orderfile: New file.
* bootstrap.conf (bootstrap_post_import_hook): Set it up.
---
 .gitattributes    |  4 ++++
 ChangeLog         |  7 +++++++
 bootstrap.conf    |  5 +++++
 etc/git.orderfile | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 69 insertions(+)
 create mode 100644 .gitattributes
 create mode 100644 etc/git.orderfile

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 00000000..68d2d121
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,4 @@
+# See ./bootstrap for some helpful ~/.gitconfig or .git/config settings
+# needed for using these attributes effectively.
+ChangeLog merge=merge-changelog
+*.texi* diff=texinfo
diff --git a/ChangeLog b/ChangeLog
index 67847c20..5797cb0f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2020-02-25  Eric Blake  <address@hidden>
+
+       maint: Saner diff output
+       * .gitattributes: New file.
+       * etc/git.orderfile: New file.
+       * bootstrap.conf (bootstrap_post_import_hook): Set it up.
+
 2020-02-25  Eric Blake  <address@hidden>

        * .gitignore: Allow './configure -C'.
diff --git a/bootstrap.conf b/bootstrap.conf
index 2a3417e2..c9e959b1 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -138,4 +138,9 @@ bootstrap_post_import_hook ()
   done
   IFS=$oIFS
   die 'Cannot find pkg.m4; perhaps you need to install pkg-config'
+
+  # Set up saner diff order
+  if ! (git config --get diff.orderFile) >/dev/null 2>&1; then
+     git config diff.orderFile etc/git.orderfile
+  fi
 }
diff --git a/etc/git.orderfile b/etc/git.orderfile
new file mode 100644
index 00000000..55db71ed
--- /dev/null
+++ b/etc/git.orderfile
@@ -0,1 +1,54 @@
+# Saner diff output for GNU poke
+# Copyright (C) 2020 Eric Blake
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# You can use this to change the ordering of files within patches to
+# make them easier to follow.
+#
+# Use:
+#   git diff -O etc/git.orderfile
+#
+# Or make the change permanently by doing:
+#   git config diff.orderFile etc/git.orderfile
+
+# Documentation.
+docs/*
+HACKING
+NEWS
+README
+TODO
+
+# Build files.
+configure.ac
+Makefile.am
+bootstrap.conf
+build-aux/*
+cfg.mk
+m4/*
+
+# Source files.
+src/*.h
+src/*.c
+src/*.pk
+src/*
+run.in
+
+# Pickle files.
+pickles/*
+
+# Testsuite.
+testsuite/*
+
+# Anything else last.
-- 
2.24.1