Re: [RFC PATCH v2] Allow aliases that include other aliases

> On Wed, Sep 5, 2018 at 10:56 AM Tim Schumacher <timschumi@gmx.de> wrote:
>>
>> Aliases can only contain non-alias git commands and their
>> arguments, not other user-defined aliases. Resolving further
>> (nested) aliases is prevented by breaking the loop after the
>> first alias was processed. Git then fails with a command-not-found
>> error.
>>
>> Allow resolving nested aliases by not breaking the loop in
>> run_argv() after the first alias was processed. Instead, continue
>> incrementing `done_alias` until `handle_alias()` fails, which means that
>> there are no further aliases that can be processed. Prevent looping
>> aliases by storing substituted commands in `cmd_list` and checking if
>> a command has been substituted previously.
>> ---
>>
>> This is what I've come up with to prevent looping aliases. I'm not too
>> happy with the number of indentations needed, but this seemed to be the
>> easiest way to search an array for a value.
> 
> You can just make all the new code a separate function, which reduces
> indentation.

> 
> There's another thing I wanted (but probably a wrong thing to want):
> if I define alias 'foo' in ~/.gitconfig, then I'd like to modify it in
> some project by redefining it as alias.foo='foo --something' in
> $GIT_DIR/config. This results in alias loop, but the loop is broken by
> looking up 'foo' from a higher level config file instead.
> 
> This is not easy to do, and as I mentioned, I'm not even sure if it's
> a sane thing to do.

> 
>> +               /* Increase the array size and add the current
>> +                * command to it.
>> +                */
> 
> I think this is pretty clear from the code, you don't need to add a
> comment to explain how the next few lines work. Same comment for the
> next comment block.

> 
>> +               cmd_list_alloc += strlen(*argv[0]) + 1;
>> +               REALLOC_ARRAY(cmd_list, cmd_list_alloc);
>> +               cmd_list[done_alias] = *argv[0];
>> +
>> +               /* Search the array for occurrences of that command,
>> +                * abort if something has been found.
>> +                */
>> +               for (int i = 0; i < done_alias; i++) {
>> +                       if (!strcmp(cmd_list[i], *argv[0])) {
>> +                               die("loop alias: %s is called twice",
> 
> Please wrap the string in _() so that it can be translated in
> different languages.

> 
>> +                                   cmd_list[done_alias]);
>> +                       }
>> +               }
>> +