Re: [PATCH for-5.1 5/8] qemu-option: Fix has_help_option()'s sloppy parsing

[Eric Blake <eblake@redhat.com>]

On 4/9/20 10:30 AM, Markus Armbruster wrote:
> has_help_option() uses its own parser.  It's inconsistent with
> qemu_opts_parse(), as demonstrated by test-qemu-opts case
> /qemu-opts/has_help_option.  Fix by reusing the common parser.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>   tests/test-qemu-opts.c |  2 +-
>   util/qemu-option.c     | 39 +++++++++++++++++++--------------------
>   2 files changed, 20 insertions(+), 21 deletions(-)
> 
> diff --git a/tests/test-qemu-opts.c b/tests/test-qemu-opts.c
> index 27c24bb1a2..58a4ea2408 100644
> --- a/tests/test-qemu-opts.c
> +++ b/tests/test-qemu-opts.c
> @@ -744,7 +744,7 @@ static void test_has_help_option(void)
>           { "a,help", true, true, true },
>           { "a=0,help,b", true, true, true },
>           { "help,b=1", true, true, false },
> -        { "a,b,,help", false /* BUG */, true, true },
> +        { "a,b,,help", true, true, true },

Okay, this revisits my question from 1/8.

I guess the argument is that since 'b,help' is NOT a valid option name 
(only as an option value), that we are instead parsing three separate 
options 'b', '', and 'help', and whether or not the empty option is 
valid, the face that 'help' is valid is what makes this return true?


> +++ b/util/qemu-option.c
> @@ -165,26 +165,6 @@ void parse_option_size(const char *name, const char *value,
>       *ret = size;
>   }
>   
> -bool has_help_option(const char *param)
> -{
> -    const char *p = param;
> -    bool result = false;
> -
> -    while (*p && !result) {
> -        char *value;
> -
> -        p = get_opt_value(p, &value);
> -        if (*p) {
> -            p++;
> -        }
> -
> -        result = is_help_option(value);

Old code: both 'help' and '?' are accepted.

> +bool has_help_option(const char *params)
> +{
> +    const char *p;
> +    char *name, *value;
> +    bool ret;
> +
> +    for (p = params; *p;) {
> +        p = get_opt_name_value(p, NULL, &name, &value);
> +        ret = !strcmp(name, "help");

New code: only 'help' is accepted.  Is the loss of '?' intentional?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org