Issue 3925: lilypond -d leads to weird output

Issue 3925: lilypond -d leads to weird output

C++ string manipulation is a fragile bolt-on onto the type system.

"-" + 'd'

evaluates to a pointer 100 bytes after a constant string "-" in the data
section.  This fixes this bug, and also changes the fixed message from

    lilypond: option `-d, `--define-default'' requires an argument

to

    lilypond: option `-d, --define-default' requires an argument

In general, it does not appear to make sense quoting the long options
while not quoting the short options.

[lemzwerg, 2014-06-01 16:00:24]

Mhmm, having quotes like

  `-foo', `--bar'     ,

or maybe

  '-foo', '--bar'     ,

to follow the latest GNU coding standard, is the correct way IMHO – the comma is
definitely *not* part of the expression.

[dak, 2014-06-01 16:23:30]

On 2014/06/01 16:00:24, lemzwerg wrote:
> Mhmm, having quotes like
> 
>   `-foo', `--bar'     ,
> 
> or maybe
> 
>   '-foo', '--bar'     ,
> 
> to follow the latest GNU coding standard, is the correct way IMHO – the comma
is
> definitely *not* part of the expression.

The Usage reference states

Basic command line options for LilyPond
---------------------------------------

The following options are supported:

‘-d, --define-default=VAR=VAL’
     See *note Advanced command line options for LilyPond::.

‘-e, --evaluate=EXPR’
[...]

and I don't see the point in diverging from this.  lilypond --help says

Options:
  -d, --define-default=SYM[=VAL]      set Scheme option SYM to VAL (default:
#t).
                                        Use -dhelp for help.
  -e, --evaluate=EXPR                 evaluate scheme code

without quotes at all, instead using formatting.  Arguably, `-d, --...' are also
formatted as one itentity here.

[lemzwerg, 2014-06-01 22:00:17]

OK, I have admittedly not looked at lilypond's help message.  I agree that it is
useful to harmonize quoting – given that

  '-f, --foo'

is not correct, I vote for *not* using any quotes, as is done e.g. with the
output of `grep --help'.  In lilypond's info manual, it should also be done as
in grep's info manual.

[dak, 2014-06-02 07:42:02]

On 2014/06/01 22:00:17, lemzwerg wrote:
> OK, I have admittedly not looked at lilypond's help message.

The help message does not use quoting.  It uses block formatting, and "-d,
--define-var" is formatted as one block.

> I agree that it is
> useful to harmonize quoting – given that
> 
>   '-f, --foo'
> 
> is not correct, I vote for *not* using any quotes, as is done e.g. with the
> output of `grep --help'.  In lilypond's info manual, it should also be done as
> in grep's info manual.

This issue is not a documentation reformatting issue.  It fixes the command line
error message bug.  If you want to file a documentation enhancement request
(which would touch quite a bit more code and ultimately all translations), feel
free to do so.

However, the current option formatting in the manual has been the result of
various issues and discussions already.  The quotes are not actually generated
explicitly, but are in the info manual incidentally because of the formatting

    @table @code

    @item -d, --define-default=@var{var}=@var{val}
[...]

In the web version, we have
<URL:http://lilypond.org/doc/v2.18/Documentation/usage/command_002dline-usage#basic-command-line-options-for-lilypond>
namely no quote characters but a font change.

We are talking here, in this issue, about an error message putting quote marks
around the option and its variant in question.

I am not going to engage in bike shedding in this issue.  Either it goes in as
`-d, --define-default' as the minimal sanity change I added on top of the bug
fix, or it goes in without the sanity fix as `-d, `--define-default'' as the
original code would do.  I'd also be willing to entertain `-d',
`--define-default' as a best guess that it was rather this which was intended by
the original code, but since this is the target of a to_string call, it would
mean that this call can output one _or_ two comma-separated quoted items, making
it harder to pick the right grammar for embedding the output.

In the light of that, I prefer erring on the safe side and returning, as
previously, a single quoted item, just removing the insane inner quote.

I repeat: this is a bug fix issue, not a reformatting issue.  Before engaging in
any endless discussion, I will rather keep this at `-d, `--define-default'' and
let someone who cares to do the work and discussion do the respective issue.