Merge branch 'jc/maint-filter-branch-epoch-date'

In 1.7.9 era, we taught "git rebase" about the raw timestamp format
but we did not teach the same trick to "filter-branch", which rolled
a similar logic on its own.  Because of this, "filter-branch" failed
to rewrite commits with ancient timestamps.

* jc/maint-filter-branch-epoch-date:
  t7003: add test to filter a branch with a commit at epoch
  date.c: Fix off by one error in object-header date parsing
  filter-branch: do not forget the '@' prefix to force git-timestamp

2 files changed, 13 insertions, 3 deletions

diff --git a/t/t7003-filter-branch.sh b/t/t7003-filter-branch.sh
index e0227730de..4d13e10de1 100755
--- a/t/t7003-filter-branch.sh
+++ b/t/t7003-filter-branch.sh
@@ -5,7 +5,8 @@ test_description='git filter-branch'
 
 test_expect_success 'setup' '
 	test_commit A &&
-	test_commit B &&
+	GIT_COMMITTER_DATE="@0 +0000" GIT_AUTHOR_DATE="@0 +0000" &&
+	test_commit --notick B &&
 	git checkout -b branch B &&
 	test_commit D &&
 	mkdir dir &&
diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 16397691d9..80daaca780 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -143,10 +143,19 @@ test_pause () {
 # Both <file> and <contents> default to <message>.
 
 test_commit () {
-	file=${2:-"$1.t"}
+	notick= &&
+	if test "z$1" = "z--notick"
+	then
+		notick=yes
+		shift
+	fi &&
+	file=${2:-"$1.t"} &&
 	echo "${3-$1}" > "$file" &&
 	git add "$file" &&
-	test_tick &&
+	if test -z "$notick"
+	then
+		test_tick
+	fi &&
 	git commit -m "$1" &&
 	git tag "$1"
 }