1 files changed, 50 insertions, 0 deletions
diff --git a/builtin/skew.c b/builtin/skew.c
new file mode 100644
index 0000000000..1046f5f546
--- /dev/null
+++ b/builtin/skew.c
@@ -0,0 +1,50 @@
+#include "cache.h"
+#include "commit.h"
+#include "diff.h"
+#include "revision.h"
+
+unsigned long worst_skew = 0;
+
+static void check_skew_recurse(struct commit *c, unsigned long when)
+{
+	struct commit_list *p;
+
+	if (c->object.flags & SEEN)
+		return;
+	c->object.flags |= SEEN;
+
+	if (parse_commit(c) < 0)
+		return;
+
+	if (c->date > when) {
+		unsigned long skew = c->date - when;
+		if (skew > worst_skew)
+			worst_skew = skew;
+	}
+
+	for (p = c->parents; p; p = p->next)
+		check_skew_recurse(p->item, c->date < when ? c->date : when);
+}
+
+static void check_skew(struct commit *c)
+{
+	check_skew_recurse(c, time(NULL));
+}
+
+int cmd_skew(int argc, const char **argv, const char *prefix) {
+	struct rev_info revs;
+	int i;
+
+	git_config(git_default_config, NULL);
+	init_revisions(&revs, prefix);
+	argc = setup_revisions(argc, argv, &revs, NULL);
+
+	for (i = 0; i < revs.pending.nr; i++) {
+		struct object *o = revs.pending.objects[i].item;
+		if (o->type == OBJ_COMMIT)
+			check_skew((struct commit *)o);
+	}
+
+	printf("%lu\n", worst_skew);
+	return 0;
+}