filter-branch: use git-sh-setup's ident parsing functions

This saves us some code, but it also reduces the number of
processes we start for each filtered commit. Since we can
parse both author and committer in the same sed invocation,
we save one process. And since the new interface avoids tr,
we save 4 processes.

It also avoids using "tr", which has had some odd
portability problems reported with from Solaris's xpg6
version.

We also tweak one of the tests in t7003 to double-check that
we are properly exporting the variables (because test-lib.sh
exports GIT_AUTHOR_NAME, it will be automatically exported
in subprograms. We override this to make sure that
filter-branch handles it properly itself).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-filter-branch.sh

@@ -64,37 +64,19 @@ EOF
 
 eval "$functions"
 
-# When piped a commit, output a script to set the ident of either
-# "author" or "committer
+finish_ident() {
+	# Ensure non-empty id name.
+	echo "case \"\$GIT_$1_NAME\" in \"\") GIT_$1_NAME=\"\${GIT_$1_EMAIL%%@*}\" && export GIT_$1_NAME;; esac"
+	# And make sure everything is exported.
+	echo "export GIT_$1_NAME"
+	echo "export GIT_$1_EMAIL"
+	echo "export GIT_$1_DATE"
+}
 
 set_ident () {
-	lid="$(echo "$1" | tr "[A-Z]" "[a-z]")"
-	uid="$(echo "$1" | tr "[a-z]" "[A-Z]")"
-	pick_id_script='
-		/^'$lid' /{
-			s/'\''/'\''\\'\'\''/g
-			h
-			s/^'$lid' \([^<]*\) <[^>]*> .*$/\1/
-			s/'\''/'\''\'\'\''/g
-			s/.*/GIT_'$uid'_NAME='\''&'\''; export GIT_'$uid'_NAME/p
-
-			g
-			s/^'$lid' [^<]* <\([^>]*\)> .*$/\1/
-			s/'\''/'\''\'\'\''/g
-			s/.*/GIT_'$uid'_EMAIL='\''&'\''; export GIT_'$uid'_EMAIL/p
-
-			g
-			s/^'$lid' [^<]* <[^>]*> \(.*\)$/@\1/
-			s/'\''/'\''\'\'\''/g
-			s/.*/GIT_'$uid'_DATE='\''&'\''; export GIT_'$uid'_DATE/p
-
-			q
-		}
-	'
-
-	LANG=C LC_ALL=C sed -ne "$pick_id_script"
-	# Ensure non-empty id name.
-	echo "case \"\$GIT_${uid}_NAME\" in \"\") GIT_${uid}_NAME=\"\${GIT_${uid}_EMAIL%%@*}\" && export GIT_${uid}_NAME;; esac"
+	parse_ident_from_commit author AUTHOR committer COMMITTER
+	finish_ident AUTHOR
+	finish_ident COMMITTER
 }
 
 USAGE="[--env-filter <command>] [--tree-filter <command>]
@@ -320,10 +302,8 @@ while read commit parents; do
 	git cat-file commit "$commit" >../commit ||
 		die "Cannot read commit $commit"
 
-	eval "$(set_ident AUTHOR <../commit)" ||
-		die "setting author failed for commit $commit"
-	eval "$(set_ident COMMITTER <../commit)" ||
-		die "setting committer failed for commit $commit"
+	eval "$(set_ident <../commit)" ||
+		die "setting author/committer failed for commit $commit"
 	eval "$filter_env" < /dev/null ||
 		die "env filter failed: $filter_env"
 

t/t7003-filter-branch.sh

@@ -167,10 +167,11 @@ test_expect_success 'author information is preserved' '
 	test_tick &&
 	GIT_AUTHOR_NAME="B V Uips" git commit -m bvuips &&
 	git branch preserved-author &&
-	git filter-branch -f --msg-filter "cat; \
+	(sane_unset GIT_AUTHOR_NAME &&
+	 git filter-branch -f --msg-filter "cat; \
 			test \$GIT_COMMIT != $(git rev-parse master) || \
 			echo Hallo" \
-		preserved-author &&
+		preserved-author) &&
 	test 1 = $(git rev-list --author="B V Uips" preserved-author | wc -l)
 '