thodg/libgit2

diff --git a/src/config_file.c b/src/config_file.c
index 0f4eb0e..c95ad67 100644
--- a/src/config_file.c
+++ b/src/config_file.c
@@ -1075,6 +1075,10 @@ static int read_on_variable(
 	GIT_UNUSED(line);
 	GIT_UNUSED(line_len);
 
+	if (!current_section) {
+		giterr_set(GITERR_CONFIG, "no section for key: %s", var_name);
+		return -1;
+	}
 	git__strtolower(var_name);
 	git_buf_printf(&buf, "%s.%s", current_section, var_name);
 	git__free(var_name);