Re: [PATCH 06/14] pull: support pull.ff config

diff --git a/builtin/pull.c b/builtin/pull.c
index 8982fdf..b305a47 100644
--- a/builtin/pull.c
+++ b/builtin/pull.c

@@ -209,6 +209,28 @@ static void argv_push_force(struct argv_array *arr)
 		argv_array_push(arr, "-f");
 }
 
+/**
+ * If pull.ff is "true", returns "--ff". If pull.ff is "false", returns
+ * "--no-ff". If pull.ff is "only", returns "--ff-only". Otherwise, returns
+ * NULL.
+ */
+static const char *config_get_ff(void)
+{
+	const char *value;
+
+	if (git_config_get_value("pull.ff", &value))
+		return NULL;
+	switch (git_config_maybe_bool("pull.ff", value)) {
+		case 0:
+			return "--no-ff";
+		case 1:
+			return "--ff";
+	}
+	if (!strcmp("pull.ff", "only"))