[sysadmin-bin: 1/168] Add upstream post-receive-email

[Andrea Veri <av src gnome org>]

commit bb72fbcda168d9adbe0985139d38d10700f47d1d
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Tue Jan 27 15:11:14 2009 -0500

    Add upstream post-receive-email
    
    Add the post-receive-email script from git contrib in preparation
    for hacking it into appropriate shape for GNOME.

 post-receive-email |  644 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 644 insertions(+), 0 deletions(-)
---
diff --git a/post-receive-email b/post-receive-email
new file mode 100644
index 0000000..4136895
--- /dev/null
+++ b/post-receive-email
@@ -0,0 +1,644 @@
+#!/bin/sh
+#
+# Copyright (c) 2007 Andy Parkins
+#
+# An example hook script to mail out commit update information.  This hook
+# sends emails listing new revisions to the repository introduced by the
+# change being reported.  The rule is that (for branch updates) each commit
+# will appear on one email and one email only.
+#
+# This hook is stored in the contrib/hooks directory.  Your distribution
+# will have put this somewhere standard.  You should make this script
+# executable then link to it in the repository you would like to use it in.
+# For example, on debian the hook is stored in
+# /usr/share/doc/git-core/contrib/hooks/post-receive-email:
+#
+#  chmod a+x post-receive-email
+#  cd /path/to/your/repository.git
+#  ln -sf /usr/share/doc/git-core/contrib/hooks/post-receive-email hooks/post-receive
+#
+# This hook script assumes it is enabled on the central repository of a
+# project, with all users pushing only to it and not between each other.  It
+# will still work if you don't operate in that style, but it would become
+# possible for the email to be from someone other than the person doing the
+# push.
+#
+# Config
+# ------
+# hooks.mailinglist
+#   This is the list that all pushes will go to; leave it blank to not send
+#   emails for every ref update.
+# hooks.announcelist
+#   This is the list that all pushes of annotated tags will go to.  Leave it
+#   blank to default to the mailinglist field.  The announce emails lists
+#   the short log summary of the changes since the last annotated tag.
+# hooks.envelopesender
+#   If set then the -f option is passed to sendmail to allow the envelope
+#   sender address to be set
+# hooks.emailprefix
+#   All emails have their subjects prefixed with this prefix, or "[SCM]"
+#   if emailprefix is unset, to aid filtering
+#
+# Notes
+# -----
+# All emails include the headers "X-Git-Refname", "X-Git-Oldrev",
+# "X-Git-Newrev", and "X-Git-Reftype" to enable fine tuned filtering and
+# give information for debugging.
+#
+
+# ---------------------------- Functions
+
+#
+# Top level email generation function.  This decides what type of update
+# this is and calls the appropriate body-generation routine after outputting
+# the common header
+#
+# Note this function doesn't actually generate any email output, that is
+# taken care of by the functions it calls:
+#  - generate_email_header
+#  - generate_create_XXXX_email
+#  - generate_update_XXXX_email
+#  - generate_delete_XXXX_email
+#  - generate_email_footer
+#
+generate_email()
+{
+	# --- Arguments
+	oldrev=$(git rev-parse $1)
+	newrev=$(git rev-parse $2)
+	refname="$3"
+
+	# --- Interpret
+	# 0000->1234 (create)
+	# 1234->2345 (update)
+	# 2345->0000 (delete)
+	if expr "$oldrev" : '0*$' >/dev/null
+	then
+		change_type="create"
+	else
+		if expr "$newrev" : '0*$' >/dev/null
+		then
+			change_type="delete"
+		else
+			change_type="update"
+		fi
+	fi
+
+	# --- Get the revision types
+	newrev_type=$(git cat-file -t $newrev 2> /dev/null)
+	oldrev_type=$(git cat-file -t "$oldrev" 2> /dev/null)
+	case "$change_type" in
+	create|update)
+		rev="$newrev"
+		rev_type="$newrev_type"
+		;;
+	delete)
+		rev="$oldrev"
+		rev_type="$oldrev_type"
+		;;
+	esac
+
+	# The revision type tells us what type the commit is, combined with
+	# the location of the ref we can decide between
+	#  - working branch
+	#  - tracking branch
+	#  - unannoted tag
+	#  - annotated tag
+	case "$refname","$rev_type" in
+		refs/tags/*,commit)
+			# un-annotated tag
+			refname_type="tag"
+			short_refname=${refname##refs/tags/}
+			;;
+		refs/tags/*,tag)
+			# annotated tag
+			refname_type="annotated tag"
+			short_refname=${refname##refs/tags/}
+			# change recipients
+			if [ -n "$announcerecipients" ]; then
+				recipients="$announcerecipients"
+			fi
+			;;
+		refs/heads/*,commit)
+			# branch
+			refname_type="branch"
+			short_refname=${refname##refs/heads/}
+			;;
+		refs/remotes/*,commit)
+			# tracking branch
+			refname_type="tracking branch"
+			short_refname=${refname##refs/remotes/}
+			echo >&2 "*** Push-update of tracking branch, $refname"
+			echo >&2 "***  - no email generated."
+			exit 0
+			;;
+		*)
+			# Anything else (is there anything else?)
+			echo >&2 "*** Unknown type of update to $refname ($rev_type)"
+			echo >&2 "***  - no email generated"
+			exit 1
+			;;
+	esac
+
+	# Check if we've got anyone to send to
+	if [ -z "$recipients" ]; then
+		case "$refname_type" in
+			"annotated tag")
+				config_name="hooks.announcelist"
+				;;
+			*)
+				config_name="hooks.mailinglist"
+				;;
+		esac
+		echo >&2 "*** $config_name is not set so no email will be sent"
+		echo >&2 "*** for $refname update $oldrev->$newrev"
+		exit 0
+	fi
+
+	# Email parameters
+	# The email subject will contain the best description of the ref
+	# that we can build from the parameters
+	describe=$(git describe $rev 2>/dev/null)
+	if [ -z "$describe" ]; then
+		describe=$rev
+	fi
+
+	generate_email_header
+
+	# Call the correct body generation function
+	fn_name=general
+	case "$refname_type" in
+	"tracking branch"|branch)
+		fn_name=branch
+		;;
+	"annotated tag")
+		fn_name=atag
+		;;
+	esac
+	generate_${change_type}_${fn_name}_email
+
+	generate_email_footer
+}
+
+generate_email_header()
+{
+	# --- Email (all stdout will be the email)
+	# Generate header
+	cat <<-EOF
+	To: $recipients
+	Subject: ${emailprefix}$projectdesc $refname_type, $short_refname, ${change_type}d. $describe
+	X-Git-Refname: $refname
+	X-Git-Reftype: $refname_type
+	X-Git-Oldrev: $oldrev
+	X-Git-Newrev: $newrev
+
+	This is an automated email from the git hooks/post-receive script. It was
+	generated because a ref change was pushed to the repository containing
+	the project "$projectdesc".
+
+	The $refname_type, $short_refname has been ${change_type}d
+	EOF
+}
+
+generate_email_footer()
+{
+	SPACE=" "
+	cat <<-EOF
+
+
+	hooks/post-receive
+	--${SPACE}
+	$projectdesc
+	EOF
+}
+
+# --------------- Branches
+
+#
+# Called for the creation of a branch
+#
+generate_create_branch_email()
+{
+	# This is a new branch and so oldrev is not valid
+	echo "        at  $newrev ($newrev_type)"
+	echo ""
+
+	echo $LOGBEGIN
+	# This shows all log entries that are not already covered by
+	# another ref - i.e. commits that are now accessible from this
+	# ref that were previously not accessible
+	# (see generate_update_branch_email for the explanation of this
+	# command)
+	git rev-parse --not --branches | grep -v $(git rev-parse $refname) |
+	git rev-list --pretty --stdin $newrev
+	echo $LOGEND
+}
+
+#
+# Called for the change of a pre-existing branch
+#
+generate_update_branch_email()
+{
+	# Consider this:
+	#   1 --- 2 --- O --- X --- 3 --- 4 --- N
+	#
+	# O is $oldrev for $refname
+	# N is $newrev for $refname
+	# X is a revision pointed to by some other ref, for which we may
+	#   assume that an email has already been generated.
+	# In this case we want to issue an email containing only revisions
+	# 3, 4, and N.  Given (almost) by
+	#
+	#  git rev-list N ^O --not --all
+	#
+	# The reason for the "almost", is that the "--not --all" will take
+	# precedence over the "N", and effectively will translate to
+	#
+	#  git rev-list N ^O ^X ^N
+	#
+	# So, we need to build up the list more carefully.  git rev-parse
+	# will generate a list of revs that may be fed into git rev-list.
+	# We can get it to make the "--not --all" part and then filter out
+	# the "^N" with:
+	#
+	#  git rev-parse --not --all | grep -v N
+	#
+	# Then, using the --stdin switch to git rev-list we have effectively
+	# manufactured
+	#
+	#  git rev-list N ^O ^X
+	#
+	# This leaves a problem when someone else updates the repository
+	# while this script is running.  Their new value of the ref we're
+	# working on would be included in the "--not --all" output; and as
+	# our $newrev would be an ancestor of that commit, it would exclude
+	# all of our commits.  What we really want is to exclude the current
+	# value of $refname from the --not list, rather than N itself.  So:
+	#
+	#  git rev-parse --not --all | grep -v $(git rev-parse $refname)
+	#
+	# Get's us to something pretty safe (apart from the small time
+	# between refname being read, and git rev-parse running - for that,
+	# I give up)
+	#
+	#
+	# Next problem, consider this:
+	#   * --- B --- * --- O ($oldrev)
+	#          \
+	#           * --- X --- * --- N ($newrev)
+	#
+	# That is to say, there is no guarantee that oldrev is a strict
+	# subset of newrev (it would have required a --force, but that's
+	# allowed).  So, we can't simply say rev-list $oldrev..$newrev.
+	# Instead we find the common base of the two revs and list from
+	# there.
+	#
+	# As above, we need to take into account the presence of X; if
+	# another branch is already in the repository and points at some of
+	# the revisions that we are about to output - we don't want them.
+	# The solution is as before: git rev-parse output filtered.
+	#
+	# Finally, tags: 1 --- 2 --- O --- T --- 3 --- 4 --- N
+	#
+	# Tags pushed into the repository generate nice shortlog emails that
+	# summarise the commits between them and the previous tag.  However,
+	# those emails don't include the full commit messages that we output
+	# for a branch update.  Therefore we still want to output revisions
+	# that have been output on a tag email.
+	#
+	# Luckily, git rev-parse includes just the tool.  Instead of using
+	# "--all" we use "--branches"; this has the added benefit that
+	# "remotes/" will be ignored as well.
+
+	# List all of the revisions that were removed by this update, in a
+	# fast forward update, this list will be empty, because rev-list O
+	# ^N is empty.  For a non fast forward, O ^N is the list of removed
+	# revisions
+	fast_forward=""
+	rev=""
+	for rev in $(git rev-list $newrev..$oldrev)
+	do
+		revtype=$(git cat-file -t "$rev")
+		echo "  discards  $rev ($revtype)"
+	done
+	if [ -z "$rev" ]; then
+		fast_forward=1
+	fi
+
+	# List all the revisions from baserev to newrev in a kind of
+	# "table-of-contents"; note this list can include revisions that
+	# have already had notification emails and is present to show the
+	# full detail of the change from rolling back the old revision to
+	# the base revision and then forward to the new revision
+	for rev in $(git rev-list $oldrev..$newrev)
+	do
+		revtype=$(git cat-file -t "$rev")
+		echo "       via  $rev ($revtype)"
+	done
+
+	if [ "$fast_forward" ]; then
+		echo "      from  $oldrev ($oldrev_type)"
+	else
+		#  1. Existing revisions were removed.  In this case newrev
+		#     is a subset of oldrev - this is the reverse of a
+		#     fast-forward, a rewind
+		#  2. New revisions were added on top of an old revision,
+		#     this is a rewind and addition.
+
+		# (1) certainly happened, (2) possibly.  When (2) hasn't
+		# happened, we set a flag to indicate that no log printout
+		# is required.
+
+		echo ""
+
+		# Find the common ancestor of the old and new revisions and
+		# compare it with newrev
+		baserev=$(git merge-base $oldrev $newrev)
+		rewind_only=""
+		if [ "$baserev" = "$newrev" ]; then
+			echo "This update discarded existing revisions and left the branch pointing at"
+			echo "a previous point in the repository history."
+			echo ""
+			echo " * -- * -- N ($newrev)"
+			echo "            \\"
+			echo "             O -- O -- O ($oldrev)"
+			echo ""
+			echo "The removed revisions are not necessarilly gone - if another reference"
+			echo "still refers to them they will stay in the repository."
+			rewind_only=1
+		else
+			echo "This update added new revisions after undoing existing revisions.  That is"
+			echo "to say, the old revision is not a strict subset of the new revision.  This"
+			echo "situation occurs when you --force push a change and generate a repository"
+			echo "containing something like this:"
+			echo ""
+			echo " * -- * -- B -- O -- O -- O ($oldrev)"
+			echo "            \\"
+			echo "             N -- N -- N ($newrev)"
+			echo ""
+			echo "When this happens we assume that you've already had alert emails for all"
+			echo "of the O revisions, and so we here report only the revisions in the N"
+			echo "branch from the common base, B."
+		fi
+	fi
+
+	echo ""
+	if [ -z "$rewind_only" ]; then
+		echo "Those revisions listed above that are new to this repository have"
+		echo "not appeared on any other notification email; so we list those"
+		echo "revisions in full, below."
+
+		echo ""
+		echo $LOGBEGIN
+		git rev-parse --not --branches | grep -v $(git rev-parse $refname) |
+		git rev-list --pretty --stdin $oldrev..$newrev
+
+		# XXX: Need a way of detecting whether git rev-list actually
+		# outputted anything, so that we can issue a "no new
+		# revisions added by this update" message
+
+		echo $LOGEND
+	else
+		echo "No new revisions were added by this update."
+	fi
+
+	# The diffstat is shown from the old revision to the new revision.
+	# This is to show the truth of what happened in this change.
+	# There's no point showing the stat from the base to the new
+	# revision because the base is effectively a random revision at this
+	# point - the user will be interested in what this revision changed
+	# - including the undoing of previous revisions in the case of
+	# non-fast forward updates.
+	echo ""
+	echo "Summary of changes:"
+	git diff-tree --stat --summary --find-copies-harder $oldrev..$newrev
+}
+
+#
+# Called for the deletion of a branch
+#
+generate_delete_branch_email()
+{
+	echo "       was  $oldrev"
+	echo ""
+	echo $LOGEND
+	git show -s --pretty=oneline $oldrev
+	echo $LOGEND
+}
+
+# --------------- Annotated tags
+
+#
+# Called for the creation of an annotated tag
+#
+generate_create_atag_email()
+{
+	echo "        at  $newrev ($newrev_type)"
+
+	generate_atag_email
+}
+
+#
+# Called for the update of an annotated tag (this is probably a rare event
+# and may not even be allowed)
+#
+generate_update_atag_email()
+{
+	echo "        to  $newrev ($newrev_type)"
+	echo "      from  $oldrev (which is now obsolete)"
+
+	generate_atag_email
+}
+
+#
+# Called when an annotated tag is created or changed
+#
+generate_atag_email()
+{
+	# Use git for-each-ref to pull out the individual fields from the
+	# tag
+	eval $(git for-each-ref --shell --format='
+	tagobject=%(*objectname)
+	tagtype=%(*objecttype)
+	tagger=%(taggername)
+	tagged=%(taggerdate)' $refname
+	)
+
+	echo "   tagging  $tagobject ($tagtype)"
+	case "$tagtype" in
+	commit)
+
+		# If the tagged object is a commit, then we assume this is a
+		# release, and so we calculate which tag this tag is
+		# replacing
+		prevtag=$(git describe --abbrev=0 $newrev^ 2>/dev/null)
+
+		if [ -n "$prevtag" ]; then
+			echo "  replaces  $prevtag"
+		fi
+		;;
+	*)
+		echo "    length  $(git cat-file -s $tagobject) bytes"
+		;;
+	esac
+	echo " tagged by  $tagger"
+	echo "        on  $tagged"
+
+	echo ""
+	echo $LOGBEGIN
+
+	# Show the content of the tag message; this might contain a change
+	# log or release notes so is worth displaying.
+	git cat-file tag $newrev | sed -e '1,/^$/d'
+
+	echo ""
+	case "$tagtype" in
+	commit)
+		# Only commit tags make sense to have rev-list operations
+		# performed on them
+		if [ -n "$prevtag" ]; then
+			# Show changes since the previous release
+			git rev-list --pretty=short "$prevtag..$newrev" | git shortlog
+		else
+			# No previous tag, show all the changes since time
+			# began
+			git rev-list --pretty=short $newrev | git shortlog
+		fi
+		;;
+	*)
+		# XXX: Is there anything useful we can do for non-commit
+		# objects?
+		;;
+	esac
+
+	echo $LOGEND
+}
+
+#
+# Called for the deletion of an annotated tag
+#
+generate_delete_atag_email()
+{
+	echo "       was  $oldrev"
+	echo ""
+	echo $LOGEND
+	git show -s --pretty=oneline $oldrev
+	echo $LOGEND
+}
+
+# --------------- General references
+
+#
+# Called when any other type of reference is created (most likely a
+# non-annotated tag)
+#
+generate_create_general_email()
+{
+	echo "        at  $newrev ($newrev_type)"
+
+	generate_general_email
+}
+
+#
+# Called when any other type of reference is updated (most likely a
+# non-annotated tag)
+#
+generate_update_general_email()
+{
+	echo "        to  $newrev ($newrev_type)"
+	echo "      from  $oldrev"
+
+	generate_general_email
+}
+
+#
+# Called for creation or update of any other type of reference
+#
+generate_general_email()
+{
+	# Unannotated tags are more about marking a point than releasing a
+	# version; therefore we don't do the shortlog summary that we do for
+	# annotated tags above - we simply show that the point has been
+	# marked, and print the log message for the marked point for
+	# reference purposes
+	#
+	# Note this section also catches any other reference type (although
+	# there aren't any) and deals with them in the same way.
+
+	echo ""
+	if [ "$newrev_type" = "commit" ]; then
+		echo $LOGBEGIN
+		git show --no-color --root -s --pretty=medium $newrev
+		echo $LOGEND
+	else
+		# What can we do here?  The tag marks an object that is not
+		# a commit, so there is no log for us to display.  It's
+		# probably not wise to output git cat-file as it could be a
+		# binary blob.  We'll just say how big it is
+		echo "$newrev is a $newrev_type, and is $(git cat-file -s $newrev) bytes long."
+	fi
+}
+
+#
+# Called for the deletion of any other type of reference
+#
+generate_delete_general_email()
+{
+	echo "       was  $oldrev"
+	echo ""
+	echo $LOGEND
+	git show -s --pretty=oneline $oldrev
+	echo $LOGEND
+}
+
+send_mail()
+{
+	if [ -n "$envelopesender" ]; then
+		/usr/sbin/sendmail -t -f "$envelopesender"
+	else
+		/usr/sbin/sendmail -t
+	fi
+}
+
+# ---------------------------- main()
+
+# --- Constants
+LOGBEGIN="- Log -----------------------------------------------------------------"
+LOGEND="-----------------------------------------------------------------------"
+
+# --- Config
+# Set GIT_DIR either from the working directory, or from the environment
+# variable.
+GIT_DIR=$(git rev-parse --git-dir 2>/dev/null)
+if [ -z "$GIT_DIR" ]; then
+	echo >&2 "fatal: post-receive: GIT_DIR not set"
+	exit 1
+fi
+
+projectdesc=$(sed -ne '1p' "$GIT_DIR/description")
+# Check if the description is unchanged from it's default, and shorten it to
+# a more manageable length if it is
+if expr "$projectdesc" : "Unnamed repository.*$" >/dev/null
+then
+	projectdesc="UNNAMED PROJECT"
+fi
+
+recipients=$(git config hooks.mailinglist)
+announcerecipients=$(git config hooks.announcelist)
+envelopesender=$(git config hooks.envelopesender)
+emailprefix=$(git config hooks.emailprefix || echo '[SCM] ')
+
+# --- Main loop
+# Allow dual mode: run from the command line just like the update hook, or
+# if no arguments are given then run as a hook script
+if [ -n "$1" -a -n "$2" -a -n "$3" ]; then
+	# Output to the terminal in command line mode - if someone wanted to
+	# resend an email; they could redirect the output to sendmail
+	# themselves
+	PAGER= generate_email $2 $3 $1
+else
+	while read oldrev newrev refname
+	do
+		generate_email $oldrev $newrev $refname | send_mail
+	done
+fi