Re: [PATCH v3 3/3] config: add '--show-origin' option to print the origin of a config value

> On Sat, Feb 13, 2016 at 03:24:16PM +0100, larsxschneider@gmail.com wrote:
> 
>> From: Lars Schneider <larsxschneider@gmail.com>
>> 
>> If config values are queried using 'git config' (e.g. via --get,
>> --get-all, --get-regexp, or --list flag) then it is sometimes hard to
>> find the configuration file where the values were defined.
>> 
>> Teach 'git config' the '--show-origin' option to print the source
>> configuration file for every printed value.
> 
> Thanks, I think this version fixes the correctness issues I mentioned
> earlier. I do still have nits to pick (of course :) ), that we may or
> may not want to deal with.
> 
>> +static void show_config_origin(struct strbuf *buf)
>> +{
>> +	const char term = end_null ? '\0' : '\t';
>> +	const char *type;
>> +	const char *name;
>> +
>> +	current_config_type_name(&type, &name);
> 
> This double out-parameter feels like a clunky interface.
> 
> I was tempted to suggest that we simply make the "struct config_source"
> available to builtin/config.c (which is already pretty intimate with the
> rest of the config code), and then it can pick out what it wants. But
> there _is_ some logic in the function to convert the NULL "cf" into
> "cmdline".
> 
> Perhaps it would be simpler to just have two accessor functions, and do:
> 
>  strbuf_addstr(buf, current_config_type());
>  ...
>  strbuf_addstr(buf, current_config_name());
> 
> I admit it is a pretty minor point, though.

> 
>> static int show_all_config(const char *key_, const char *value_, void *cb)
>> {
>> +	if (show_origin) {
>> +       struct strbuf buf = STRBUF_INIT;
>> +       show_config_origin(&buf);
>> +       fwrite(buf.buf, 1, buf.len, stdout);
>> +       strbuf_release(&buf);
>> +	}
> 
> The indentation is funky here.

> 
> The use of fwrite() to catch the embedded NULs is subtle enough that it
> might be worth a comment.
> 
> It also made me wonder how format_config() handles this. It looks like
> we send the result eventually to fwrite() there, so it all works (and it
> does _not_ have the comment I mentioned :) ).

> 
>> +test_expect_success '--show-origin' '
>> +	>.git/config &&
>> +	>"$HOME"/.gitconfig &&
>> +	INCLUDE_DIR="$HOME/include" &&
>> +	mkdir -p "$INCLUDE_DIR" &&
>> +	cat >"$INCLUDE_DIR"/absolute.include <<-EOF &&
>> +		[user]
>> +			absolute = include
>> +	EOF
>> +	cat >"$INCLUDE_DIR"/relative.include <<-EOF &&
>> +		[user]
>> +			relative = include
>> +	EOF
>> +	test_config_global user.global "true" &&
>> +	test_config_global user.override "global" &&
>> +	test_config_global include.path "$INCLUDE_DIR"/absolute.include &&
>> +	test_config include.path ../include/relative.include &&
>> +	test_config user.local "true" &&
>> +	test_config user.override "local" &&
>> +
>> +	cat >expect <<-EOF &&
>> +		file:$HOME/.gitconfig	user.global=true
>> +		file:$HOME/.gitconfig	user.override=global
>> +		file:$HOME/.gitconfig	include.path=$INCLUDE_DIR/absolute.include
>> +		file:$INCLUDE_DIR/absolute.include	user.absolute=include
>> +		file:.git/config	include.path=../include/relative.include
>> +		file:.git/../include/relative.include	user.relative=include
>> +		file:.git/config	user.local=true
>> +		file:.git/config	user.override=local
>> +		cmdline:	user.cmdline=true
>> +	EOF
>> +	git -c user.cmdline=true config --list --show-origin >output &&
>> +	test_cmp expect output &&
>> +
>> +	cat >expect <<-EOF &&
>> +		file:$HOME/.gitconfigQuser.global
>> +		trueQfile:$HOME/.gitconfigQuser.override
>> +		globalQfile:$HOME/.gitconfigQinclude.path
>> +		$INCLUDE_DIR/absolute.includeQfile:$INCLUDE_DIR/absolute.includeQuser.absolute
>> +		includeQfile:.git/configQinclude.path
>> +		../include/relative.includeQfile:.git/../include/relative.includeQuser.relative
>> +		includeQfile:.git/configQuser.local
>> +		trueQfile:.git/configQuser.override
>> +		localQcmdline:Quser.cmdline
>> +		trueQ
>> +	EOF
> 
> I see you split this up more, but there's still quite a bit going on in
> this one block. IMHO, it would be more customary in our tests to put the
> setup into one test_expect_success block, then each of these
> expect-run-cmp blocks into their own test_expect_success.
> 
> It does mean that the setup mutates the global test state for further
> tests (and you should stop using test_config_*, which clean up at the
> end of the block), but I think that's the right thing here. The point of
> test_config is "flip on this switch just for a moment, so we can test
> its effect without hurting further tests". But these are config tests in
> the first place, and it is OK for them to show a progression of
> mutations of the config (you'll note that like the other tests in this
> script, you are clearing out .git/config in the first place).
>