When parsing the "key", "command", and "cmd" trailer config, we just make a copy of the value string. If we see an implicit bool like: [trailer "foo"] key we'll segfault trying to copy a NULL pointer. We can fix this with the usual config_error_nonbool() check. I split this out from the other vanilla cases, because at first glance it looks like a better fix here would be to move the NULL check out of the switch statement. But it would change the behavior of other keys like trailer.*.ifExists, where an implicit bool is interpreted as EXISTS_DEFAULT. Signed-off-by: Jeff King <peff@xxxxxxxx> --- trailer.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/trailer.c b/trailer.c index b0e2ec224a..e4b08ed267 100644 --- a/trailer.c +++ b/trailer.c @@ -553,16 +553,22 @@ static int git_trailer_config(const char *conf_key, const char *value, case TRAILER_KEY: if (conf->key) warning(_("more than one %s"), conf_key); + if (!value) + return config_error_nonbool(conf_key); conf->key = xstrdup(value); break; case TRAILER_COMMAND: if (conf->command) warning(_("more than one %s"), conf_key); + if (!value) + return config_error_nonbool(conf_key); conf->command = xstrdup(value); break; case TRAILER_CMD: if (conf->cmd) warning(_("more than one %s"), conf_key); + if (!value) + return config_error_nonbool(conf_key); conf->cmd = xstrdup(value); break; case TRAILER_WHERE: -- 2.43.0.664.ga12c899002