trailer: add new .cmd config option

The `trailer.<token>.command` configuration variable
specifies a command (run via the shell, so it does not have
to be a single name or path to the command, but can be a
shell script), and the first occurrence of substring $ARG is
replaced with the value given to the `interpret-trailer`
command for the token in a '--trailer <token>=<value>' argument.

This has three downsides:

* The use of $ARG in the mechanism misleads the users that
the value is passed in the shell variable, and tempt them
to use $ARG more than once, but that would not work, as
the second and subsequent $ARG are not replaced.

* Because $ARG is textually replaced without regard to the
shell language syntax, even '$ARG' (inside a single-quote
pair), which a user would expect to stay intact, would be
replaced, and worse, if the value had an unmatched single
quote (imagine a name like "O'Connor", substituted into
NAME='$ARG' to make it NAME='O'Connor'), it would result in
a broken command that is not syntactically correct (or
worse).

* The first occurrence of substring `$ARG` will be replaced
with the empty string, in the command when the command is
first called to add a trailer with the specified <token>.
This is a bad design, the nature of automatic execution
causes it to add a trailer that we don't expect.

Introduce a new `trailer.<token>.cmd` configuration that
takes higher precedence to deprecate and eventually remove
`trailer.<token>.command`, which passes the value as an
argument to the command.  Instead of "$ARG", users can
refer to the value as positional argument, $1, in their
scripts. At the same time, in order to allow
`git interpret-trailers` to better simulate the behavior
of `git command -s`, 'trailer.<token>.cmd' will not
automatically execute.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: ZheNing Hu <adlternative@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
ZheNing Hu 2021-05-03 15:41:05 +00:00 committed by Junio C Hamano
parent 57dcb6575b
commit c364b7ef51
3 changed files with 175 additions and 19 deletions

View File

@ -232,6 +232,20 @@ trailer.<token>.ifmissing::
that option for trailers with the specified <token>.
trailer.<token>.command::
This option behaves in the same way as 'trailer.<token>.cmd', except
that it doesn't pass anything as argument to the specified command.
Instead the first occurrence of substring $ARG is replaced by the
value that would be passed as argument.
+
The 'trailer.<token>.command' option has been deprecated in favor of
'trailer.<token>.cmd' due to the fact that $ARG in the user's command is
only replaced once and that the original way of replacing $ARG is not safe.
+
When both 'trailer.<token>.cmd' and 'trailer.<token>.command' are given
for the same <token>, 'trailer.<token>.cmd' is used and
'trailer.<token>.command' is ignored.
trailer.<token>.cmd::
This option can be used to specify a shell command that will be called:
once to automatically add a trailer with the specified <token>, and then
each time a '--trailer <token>=<value>' argument to modify the <value> of
@ -247,15 +261,9 @@ leading and trailing whitespace trimmed off.
If some '--trailer <token>=<value>' arguments are also passed
on the command line, the command is called again once for each
of these arguments with the same <token>. And the <value> part
of these arguments, if any, will be used to replace the first
occurrence of substring `$ARG` in the command. This way the
command can produce a <value> computed from the <value> passed
in the '--trailer <token>=<value>' argument.
+
For consistency, the first occurrence of substring `$ARG` is
also replaced, this time with the empty string, in the command
when the command is first called to add a trailer with the
specified <token>.
of these arguments, if any, will be passed to the command as its
first argument. This way the command can produce a <value> computed
from the <value> passed in the '--trailer <token>=<value>' argument.
EXAMPLES
--------
@ -338,6 +346,55 @@ subject
Fix #42
------------
* Configure a 'help' trailer with a cmd use a script `glog-find-author`
which search specified author identity from git log in git repository
and show how it works:
+
------------
$ cat ~/bin/glog-find-author
#!/bin/sh
test -n "$1" && git log --author="$1" --pretty="%an <%ae>" -1 || true
$ git config trailer.help.key "Helped-by: "
$ git config trailer.help.ifExists "addIfDifferentNeighbor"
$ git config trailer.help.cmd "~/bin/glog-find-author"
$ git interpret-trailers --trailer="help:Junio" --trailer="help:Couder" <<EOF
> subject
>
> message
>
> EOF
subject
message
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Christian Couder <christian.couder@gmail.com>
------------
* Configure a 'ref' trailer with a cmd use a script `glog-grep`
to grep last relevant commit from git log in the git repository
and show how it works:
+
------------
$ cat ~/bin/glog-grep
#!/bin/sh
test -n "$1" && git log --grep "$1" --pretty=reference -1 || true
$ git config trailer.ref.key "Reference-to: "
$ git config trailer.ref.ifExists "replace"
$ git config trailer.ref.cmd "~/bin/glog-grep"
$ git interpret-trailers --trailer="ref:Add copyright notices." <<EOF
> subject
>
> message
>
> EOF
subject
message
Reference-to: 8bc9a0c769 (Add copyright notices., 2005-04-07)
------------
* Configure a 'see' trailer with a command to show the subject of a
commit that is related, and show how it works:
+

View File

@ -51,6 +51,69 @@ test_expect_success 'setup' '
EOF
'
test_expect_success 'with cmd' '
test_when_finished "git config --remove-section trailer.bug" &&
git config trailer.bug.key "Bug-maker: " &&
git config trailer.bug.ifExists "add" &&
git config trailer.bug.cmd "echo \"maybe is\"" &&
cat >expected2 <<-EOF &&
Bug-maker: maybe is him
Bug-maker: maybe is me
EOF
git interpret-trailers --trailer "bug: him" --trailer "bug:me" \
>actual2 &&
test_cmp expected2 actual2
'
test_expect_success 'with cmd and $1' '
test_when_finished "git config --remove-section trailer.bug" &&
git config trailer.bug.key "Bug-maker: " &&
git config trailer.bug.ifExists "add" &&
git config trailer.bug.cmd "echo \"\$1\" is" &&
cat >expected2 <<-EOF &&
Bug-maker: him is him
Bug-maker: me is me
EOF
git interpret-trailers --trailer "bug: him" --trailer "bug:me" \
>actual2 &&
test_cmp expected2 actual2
'
test_expect_success 'with cmd and $1 with sh -c' '
test_when_finished "git config --remove-section trailer.bug" &&
git config trailer.bug.key "Bug-maker: " &&
git config trailer.bug.ifExists "replace" &&
git config trailer.bug.cmd "sh -c \"echo who is \"\$1\"\"" &&
cat >expected2 <<-EOF &&
Bug-maker: who is me
EOF
git interpret-trailers --trailer "bug: him" --trailer "bug:me" \
>actual2 &&
test_cmp expected2 actual2
'
test_expect_success 'with cmd and $1 with shell script' '
test_when_finished "git config --remove-section trailer.bug" &&
git config trailer.bug.key "Bug-maker: " &&
git config trailer.bug.ifExists "replace" &&
git config trailer.bug.cmd "./echoscript" &&
cat >expected2 <<-EOF &&
Bug-maker: who is me
EOF
cat >echoscript <<-EOF &&
#!/bin/sh
echo who is "\$1"
EOF
chmod +x echoscript &&
git interpret-trailers --trailer "bug: him" --trailer "bug:me" \
>actual2 &&
test_cmp expected2 actual2
'
test_expect_success 'without config' '
sed -e "s/ Z\$/ /" >expected <<-\EOF &&
@ -1274,6 +1337,27 @@ test_expect_success 'setup a commit' '
git commit -m "Add file a.txt"
'
test_expect_success 'cmd takes precedence over command' '
test_when_finished "git config --unset trailer.fix.cmd" &&
git config trailer.fix.ifExists "replace" &&
git config trailer.fix.cmd "test -n \"\$1\" && git log -1 --oneline --format=\"%h (%aN)\" \
--abbrev-commit --abbrev=14 \"\$1\" || true" &&
git config trailer.fix.command "git log -1 --oneline --format=\"%h (%s)\" \
--abbrev-commit --abbrev=14 \$ARG" &&
FIXED=$(git log -1 --oneline --format="%h (%aN)" --abbrev-commit --abbrev=14 HEAD) &&
cat complex_message_body >expected2 &&
sed -e "s/ Z\$/ /" >>expected2 <<-EOF &&
Fixes: $FIXED
Acked-by= Z
Reviewed-by:
Signed-off-by: Z
Signed-off-by: A U Thor <author@example.com>
EOF
git interpret-trailers --trailer "review:" --trailer "fix=HEAD" \
<complex_message >actual2 &&
test_cmp expected2 actual2
'
test_expect_success 'with command using $ARG' '
git config trailer.fix.ifExists "replace" &&
git config trailer.fix.command "git log -1 --oneline --format=\"%h (%s)\" --abbrev-commit --abbrev=14 \$ARG" &&

View File

@ -14,6 +14,7 @@ struct conf_info {
char *name;
char *key;
char *command;
char *cmd;
enum trailer_where where;
enum trailer_if_exists if_exists;
enum trailer_if_missing if_missing;
@ -127,6 +128,7 @@ static void free_arg_item(struct arg_item *item)
free(item->conf.name);
free(item->conf.key);
free(item->conf.command);
free(item->conf.cmd);
free(item->token);
free(item->value);
free(item);
@ -216,18 +218,24 @@ static int check_if_different(struct trailer_item *in_tok,
return 1;
}
static char *apply_command(const char *command, const char *arg)
static char *apply_command(struct conf_info *conf, const char *arg)
{
struct strbuf cmd = STRBUF_INIT;
struct strbuf buf = STRBUF_INIT;
struct child_process cp = CHILD_PROCESS_INIT;
char *result;
strbuf_addstr(&cmd, command);
if (arg)
strbuf_replace(&cmd, TRAILER_ARG_STRING, arg);
strvec_push(&cp.args, cmd.buf);
if (conf->cmd) {
strbuf_addstr(&cmd, conf->cmd);
strvec_push(&cp.args, cmd.buf);
if (arg)
strvec_push(&cp.args, arg);
} else if (conf->command) {
strbuf_addstr(&cmd, conf->command);
if (arg)
strbuf_replace(&cmd, TRAILER_ARG_STRING, arg);
strvec_push(&cp.args, cmd.buf);
}
cp.env = local_repo_env;
cp.no_stdin = 1;
cp.use_shell = 1;
@ -247,7 +255,7 @@ static char *apply_command(const char *command, const char *arg)
static void apply_item_command(struct trailer_item *in_tok, struct arg_item *arg_tok)
{
if (arg_tok->conf.command) {
if (arg_tok->conf.command || arg_tok->conf.cmd) {
const char *arg;
if (arg_tok->value && arg_tok->value[0]) {
arg = arg_tok->value;
@ -257,7 +265,7 @@ static void apply_item_command(struct trailer_item *in_tok, struct arg_item *arg
else
arg = xstrdup("");
}
arg_tok->value = apply_command(arg_tok->conf.command, arg);
arg_tok->value = apply_command(&arg_tok->conf, arg);
free((char *)arg);
}
}
@ -430,6 +438,7 @@ static void duplicate_conf(struct conf_info *dst, const struct conf_info *src)
dst->name = xstrdup_or_null(src->name);
dst->key = xstrdup_or_null(src->key);
dst->command = xstrdup_or_null(src->command);
dst->cmd = xstrdup_or_null(src->cmd);
}
static struct arg_item *get_conf_item(const char *name)
@ -454,8 +463,8 @@ static struct arg_item *get_conf_item(const char *name)
return item;
}
enum trailer_info_type { TRAILER_KEY, TRAILER_COMMAND, TRAILER_WHERE,
TRAILER_IF_EXISTS, TRAILER_IF_MISSING };
enum trailer_info_type { TRAILER_KEY, TRAILER_COMMAND, TRAILER_CMD,
TRAILER_WHERE, TRAILER_IF_EXISTS, TRAILER_IF_MISSING };
static struct {
const char *name;
@ -463,6 +472,7 @@ static struct {
} trailer_config_items[] = {
{ "key", TRAILER_KEY },
{ "command", TRAILER_COMMAND },
{ "cmd", TRAILER_CMD },
{ "where", TRAILER_WHERE },
{ "ifexists", TRAILER_IF_EXISTS },
{ "ifmissing", TRAILER_IF_MISSING }
@ -542,6 +552,11 @@ static int git_trailer_config(const char *conf_key, const char *value, void *cb)
warning(_("more than one %s"), conf_key);
conf->command = xstrdup(value);
break;
case TRAILER_CMD:
if (conf->cmd)
warning(_("more than one %s"), conf_key);
conf->cmd = xstrdup(value);
break;
case TRAILER_WHERE:
if (trailer_set_where(&conf->where, value))
warning(_("unknown value '%s' for key '%s'"), value, conf_key);