Add commit-msg hook to tools to spare searching for it

commit-msg script adds change id at end of commit messages.
As this script is needed for Gerrit review system to work 
and every wireshark developer will need to download it from 
somewhere, it will be better if it is downloaded with Wireshark
sources and ready to copy to .git/hooks

Copied from AOSP Gerrit.

Change-Id: Ib3705abfedd2869462eef57690a2f430037f9cc1
Reviewed-on: https://code.wireshark.org/review/1008
Reviewed-by: Michael Mann <mmann78@netscape.net>

1 files changed, 181 insertions, 0 deletions

diff --git a/tools/commit-msg b/tools/commit-msg
new file mode 100755
index 0000000000..95a61e7806
--- /dev/null
+++ b/tools/commit-msg
@@ -0,0 +1,181 @@
+#!/bin/sh
+# From Gerrit Code Review 2.9-rc1-172-gd621a9e
+#
+# Part of Gerrit Code Review (http://code.google.com/p/gerrit/)
+#
+# Copyright (C) 2009 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+unset GREP_OPTIONS
+
+CHANGE_ID_AFTER="Bug|Issue"
+MSG="$1"
+
+# Check for, and add if missing, a unique Change-Id
+#
+add_ChangeId() {
+	clean_message=`sed -e '
+		/^diff --git .*/{
+			s///
+			q
+		}
+		/^Signed-off-by:/d
+		/^#/d
+	' "$MSG" | git stripspace`
+	if test -z "$clean_message"
+	then
+		return
+	fi
+
+	if test "false" = "`git config --bool --get gerrit.createChangeId`"
+	then
+		return
+	fi
+
+	# Does Change-Id: already exist? if so, exit (no change).
+	if grep -i '^Change-Id:' "$MSG" >/dev/null
+	then
+		return
+	fi
+
+	id=`_gen_ChangeId`
+	T="$MSG.tmp.$$"
+	AWK=awk
+	if [ -x /usr/xpg4/bin/awk ]; then
+		# Solaris AWK is just too broken
+		AWK=/usr/xpg4/bin/awk
+	fi
+
+	# How this works:
+	# - parse the commit message as (textLine+ blankLine*)*
+	# - assume textLine+ to be a footer until proven otherwise
+	# - exception: the first block is not footer (as it is the title)
+	# - read textLine+ into a variable
+	# - then count blankLines
+	# - once the next textLine appears, print textLine+ blankLine* as these
+	#   aren't footer
+	# - in END, the last textLine+ block is available for footer parsing
+	$AWK '
+	BEGIN {
+		# while we start with the assumption that textLine+
+		# is a footer, the first block is not.
+		isFooter = 0
+		footerComment = 0
+		blankLines = 0
+	}
+
+	# Skip lines starting with "#" without any spaces before it.
+	/^#/ { next }
+
+	# Skip the line starting with the diff command and everything after it,
+	# up to the end of the file, assuming it is only patch data.
+	# If more than one line before the diff was empty, strip all but one.
+	/^diff --git / {
+		blankLines = 0
+		while (getline) { }
+		next
+	}
+
+	# Count blank lines outside footer comments
+	/^$/ && (footerComment == 0) {
+		blankLines++
+		next
+	}
+
+	# Catch footer comment
+	/^\[[a-zA-Z0-9-]+:/ && (isFooter == 1) {
+		footerComment = 1
+	}
+
+	/]$/ && (footerComment == 1) {
+		footerComment = 2
+	}
+
+	# We have a non-blank line after blank lines. Handle this.
+	(blankLines > 0) {
+		print lines
+		for (i = 0; i < blankLines; i++) {
+			print ""
+		}
+
+		lines = ""
+		blankLines = 0
+		isFooter = 1
+		footerComment = 0
+	}
+
+	# Detect that the current block is not the footer
+	(footerComment == 0) && (!/^\[?[a-zA-Z0-9-]+:/ || /^[a-zA-Z0-9-]+:\/\//) {
+		isFooter = 0
+	}
+
+	{
+		# We need this information about the current last comment line
+		if (footerComment == 2) {
+			footerComment = 0
+		}
+		if (lines != "") {
+			lines = lines "\n";
+		}
+		lines = lines $0
+	}
+
+	# Footer handling:
+	# If the last block is considered a footer, splice in the Change-Id at the
+	# right place.
+	# Look for the right place to inject Change-Id by considering
+	# CHANGE_ID_AFTER. Keys listed in it (case insensitive) come first,
+	# then Change-Id, then everything else (eg. Signed-off-by:).
+	#
+	# Otherwise just print the last block, a new line and the Change-Id as a
+	# block of its own.
+	END {
+		unprinted = 1
+		if (isFooter == 0) {
+			print lines "\n"
+			lines = ""
+		}
+		changeIdAfter = "^(" tolower("'"$CHANGE_ID_AFTER"'") "):"
+		numlines = split(lines, footer, "\n")
+		for (line = 1; line <= numlines; line++) {
+			if (unprinted && match(tolower(footer[line]), changeIdAfter) != 1) {
+				unprinted = 0
+				print "Change-Id: I'"$id"'"
+			}
+			print footer[line]
+		}
+		if (unprinted) {
+			print "Change-Id: I'"$id"'"
+		}
+	}' "$MSG" > "$T" && mv "$T" "$MSG" || rm -f "$T"
+}
+_gen_ChangeIdInput() {
+	echo "tree `git write-tree`"
+	if parent=`git rev-parse "HEAD^0" 2>/dev/null`
+	then
+		echo "parent $parent"
+	fi
+	echo "author `git var GIT_AUTHOR_IDENT`"
+	echo "committer `git var GIT_COMMITTER_IDENT`"
+	echo
+	printf '%s' "$clean_message"
+}
+_gen_ChangeId() {
+	_gen_ChangeIdInput |
+	git hash-object -t commit --stdin
+}
+
+
+add_ChangeId