From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: git@vger.kernel.org
Cc: Junio C Hamano <gitster@pobox.com>, Jeff King <peff@peff.net>,
Tim Schumacher <timschumi@gmx.de>, Duy Nguyen <pclouds@gmail.com>
Subject: Re: [PATCH] alias: detect loops in mixed execution mode
Date: Fri, 19 Oct 2018 10:28:22 +0200 [thread overview]
Message-ID: <87pnw6cpcp.fsf@evledraar.gmail.com> (raw)
In-Reply-To: <20181018225739.28857-1-avarab@gmail.com>
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.
next prev parent reply other threads:[~2018-10-19 8:28 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-05 8:54 [RFC PATCH v2] Allow aliases that include other aliases Tim Schumacher
2018-09-05 15:48 ` Duy Nguyen
2018-09-05 19:02 ` Tim Schumacher
2018-09-05 17:12 ` Junio C Hamano
2018-09-05 19:12 ` Tim Schumacher
2018-09-05 17:34 ` Jeff King
2018-09-05 20:02 ` Tim Schumacher
2018-09-06 13:38 ` Ævar Arnfjörð Bjarmason
2018-09-06 14:17 ` Ævar Arnfjörð Bjarmason
2018-10-18 22:57 ` [PATCH] alias: detect loops in mixed execution mode Ævar Arnfjörð Bjarmason
2018-10-19 8:28 ` Ævar Arnfjörð Bjarmason [this message]
2018-10-19 22:09 ` Jeff King
2018-10-20 10:52 ` Ævar Arnfjörð Bjarmason
2018-10-19 22:07 ` Jeff King
2018-10-20 11:14 ` Ævar Arnfjörð Bjarmason
2018-10-20 18:58 ` Jeff King
2018-10-20 19:18 ` Ævar Arnfjörð Bjarmason
2018-10-22 21:15 ` Jeff King
2018-10-22 21:28 ` Ævar Arnfjörð Bjarmason
2018-10-22 1:23 ` Junio C Hamano
2018-10-26 8:39 ` Jeff King
2018-10-26 12:44 ` Ævar Arnfjörð Bjarmason
2018-10-29 3:44 ` Junio C Hamano
2018-10-29 14:17 ` Jeff King
2018-09-05 21:51 ` [RFC PATCH v2] Allow aliases that include other aliases Junio C Hamano
2018-09-06 10:16 ` [PATCH v3] " Tim Schumacher
2018-09-06 14:01 ` Ævar Arnfjörð Bjarmason
2018-09-06 14:57 ` Jeff King
2018-09-06 15:10 ` Ævar Arnfjörð Bjarmason
2018-09-06 16:18 ` Jeff King
2018-09-06 19:05 ` Tim Schumacher
2018-09-06 19:17 ` Jeff King
2018-09-06 14:59 ` Jeff King
2018-09-06 18:40 ` Junio C Hamano
2018-09-06 19:05 ` Jeff King
2018-09-06 19:31 ` Tim Schumacher
2018-09-07 22:44 ` [RFC PATCH v4 1/3] Add support for nested aliases Tim Schumacher
2018-09-07 22:44 ` [RFC PATCH v4 2/3] Show the call history when an alias is looping Tim Schumacher
2018-09-08 13:34 ` Duy Nguyen
2018-09-08 16:29 ` Jeff King
2018-09-07 22:44 ` [RFC PATCH v4 3/3] t0014: Introduce alias testing suite Tim Schumacher
2018-09-07 23:38 ` Eric Sunshine
2018-09-14 23:12 ` Tim Schumacher
2018-09-16 7:21 ` Eric Sunshine
2018-09-08 13:28 ` [RFC PATCH v4 1/3] Add support for nested aliases Duy Nguyen
2018-09-16 7:46 ` Tim Schumacher
2018-09-17 15:37 ` Junio C Hamano
2018-09-21 12:45 ` Tim Schumacher
2018-09-21 15:59 ` Junio C Hamano
2018-09-16 7:50 ` [PATCH v5 " Tim Schumacher
2018-09-16 7:50 ` [PATCH v5 2/3] Show the call history when an alias is looping Tim Schumacher
2018-09-16 7:50 ` [PATCH v5 3/3] t0014: Introduce an alias testing suite Tim Schumacher
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