On Thu, Oct 18 2018, Ævar Arnfjörð Bjarmason wrote:
> +static void init_cmd_history(struct strbuf *env, struct string_list *cmd_list)
> +{
> + const char *old = getenv(COMMAND_HISTORY_ENVIRONMENT);
> + struct strbuf **cmd_history, **ptr;
> +
> + if (!old || !*old)
> + return;
> +
> + strbuf_addstr(env, old);
> + strbuf_rtrim(env);
> +
> + cmd_history = strbuf_split_buf(old, strlen(old), ' ', 0);
> + for (ptr = cmd_history; *ptr; ptr++) {
> + strbuf_rtrim(*ptr);
> + string_list_append(cmd_list, (*ptr)->buf);
> + }
> + strbuf_list_free(cmd_history);
> +}
> +
> +static void add_cmd_history(struct strbuf *env, struct string_list *cmd_list,
> + const char *cmd)
> +{
> + string_list_append(cmd_list, cmd);
> + if (env->len)
> + strbuf_addch(env, ' ');
> + strbuf_addstr(env, cmd);
> + setenv(COMMAND_HISTORY_ENVIRONMENT, env->buf, 1);
> +}
> +
> static int run_argv(int *argcp, const char ***argv)
> {
> int done_alias = 0;
> - struct string_list cmd_list = STRING_LIST_INIT_NODUP;
> + struct string_list cmd_list = STRING_LIST_INIT_DUP;
> struct string_list_item *seen;
> + struct strbuf env = STRBUF_INIT;
>
> + init_cmd_history(&env, &cmd_list);
> while (1) {
> /*
> * If we tried alias and futzed with our environment,
> @@ -711,7 +742,7 @@ static int run_argv(int *argcp, const char ***argv)
> " not terminate:%s"), cmd_list.items[0].string, sb.buf);
> }
>
> - string_list_append(&cmd_list, *argv[0]);
> + add_cmd_history(&env, &cmd_list, *argv[0]);
>
> /*
> * It could be an alias -- this works around the insanity
Just to sanity check an assumption of mine: One thing I didn't do is use
sq_quote_buf() and sq_dequote_to_argv() like we do for
CONFIG_DATA_ENVIRONMENT. This is because in the case of config we need
to deal with:
$ git config alias.cfgdump
!env
$ git -c x.y=z -c "foo.bar='baz'" cfgdump|grep baz
GIT_CONFIG_PARAMETERS='x.y=z' 'foo.bar='\''baz'\'''
But in this case I don't see how a command-name would ever contain
whitespace. So we skip quoting and just delimit by space.
There's also nothing stopping you from doing e.g.:
$ GIT_COMMAND_HISTORY='foo bar' ~/g/git/git --exec-path=$PWD one
fatal: alias loop detected: expansion of 'foo' does not terminate:
foo
bar
one
two <==
three
four
five ==>
Or even confuse the code by adding a whitespace at the beginning:
$ GIT_COMMAND_HISTORY=' foo bar' ~/g/git/git --exec-path=$PWD one
fatal: alias loop detected: expansion of '' does not terminate:
foo
bar
one
two <==
three
four
five ==>
I thought none of this was worth dealing with. Worst case someone's
screwing with this, but I don't see how it would happen accidentally,
and even then we detect the infinite loop and just degrade to confusing
error messages because you decided to screw with git's GIT_* env vars.
