Merge branch 'jk/commit-dates-parsing-fix'

Tighten codepaths that parse timestamps in commit objects.

* jk/commit-dates-parsing-fix:
  show_ident_date: fix tz range check
  log: do not segfault on gmtime errors
  log: handle integer overflow in timestamps
  date: check date overflow against time_t
  fsck: report integer overflow in author timestamps
  t4212: test bogus timestamps with git-log

2 files changed, 59 insertions, 0 deletions

diff --git a/t/t1450-fsck.sh b/t/t1450-fsck.sh
index d730734fd..8c739c961 100755
--- a/t/t1450-fsck.sh
+++ b/t/t1450-fsck.sh
@@ -142,6 +142,20 @@ test_expect_success '> in name is reported' '
 	grep "error in commit $new" out
 '
 
+# date is 2^64 + 1
+test_expect_success 'integer overflow in timestamps is reported' '
+	git cat-file commit HEAD >basis &&
+	sed "s/^\\(author .*>\\) [0-9]*/\\1 18446744073709551617/" \
+		<basis >bad-timestamp &&
+	new=$(git hash-object -t commit -w --stdin <bad-timestamp) &&
+	test_when_finished "remove_object $new" &&
+	git update-ref refs/heads/bogus "$new" &&
+	test_when_finished "git update-ref -d refs/heads/bogus" &&
+	git fsck 2>out &&
+	cat out &&
+	grep "error in commit $new.*integer overflow" out
+'
+
 test_expect_success 'tag pointing to nonexistent' '
 	cat >invalid-tag <<-\EOF &&
 	object ffffffffffffffffffffffffffffffffffffffff
diff --git a/t/t4212-log-corrupt.sh b/t/t4212-log-corrupt.sh
index 93c7c366c..3fa171541 100755
--- a/t/t4212-log-corrupt.sh
+++ b/t/t4212-log-corrupt.sh
@@ -44,4 +44,49 @@ test_expect_success 'git log --format with broken author email' '
 	test_cmp expect.err actual.err
 '
 
+munge_author_date () {
+	git cat-file commit "$1" >commit.orig &&
+	sed "s/^\(author .*>\) [0-9]*/\1 $2/" <commit.orig >commit.munge &&
+	git hash-object -w -t commit commit.munge
+}
+
+test_expect_success 'unparsable dates produce sentinel value' '
+	commit=$(munge_author_date HEAD totally_bogus) &&
+	echo "Date:   Thu Jan 1 00:00:00 1970 +0000" >expect &&
+	git log -1 $commit >actual.full &&
+	grep Date <actual.full >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'unparsable dates produce sentinel value (%ad)' '
+	commit=$(munge_author_date HEAD totally_bogus) &&
+	echo >expect &&
+	git log -1 --format=%ad $commit >actual
+	test_cmp expect actual
+'
+
+# date is 2^64 + 1
+test_expect_success 'date parser recognizes integer overflow' '
+	commit=$(munge_author_date HEAD 18446744073709551617) &&
+	echo "Thu Jan 1 00:00:00 1970 +0000" >expect &&
+	git log -1 --format=%ad $commit >actual &&
+	test_cmp expect actual
+'
+
+# date is 2^64 - 2
+test_expect_success 'date parser recognizes time_t overflow' '
+	commit=$(munge_author_date HEAD 18446744073709551614) &&
+	echo "Thu Jan 1 00:00:00 1970 +0000" >expect &&
+	git log -1 --format=%ad $commit >actual &&
+	test_cmp expect actual
+'
+
+# date is within 2^63-1, but enough to choke glibc's gmtime
+test_expect_success 'absurdly far-in-future dates produce sentinel' '
+	commit=$(munge_author_date HEAD 999999999999999999) &&
+	echo "Thu Jan 1 00:00:00 1970 +0000" >expect &&
+	git log -1 --format=%ad $commit >actual &&
+	test_cmp expect actual
+'
+
 test_done