After fix of bug#25192, load_defaults() will add an args separator
to distinguish options loaded from configure files from that provided
in the command line. One problem of this is that the args separator
would be added no matter the application need it or not.
Fixed the problem by adding an option:
bool my_getopt_use_args_separator;
to control whether the separator will be added or not. And also
added functions:
bool my_getopt_is_args_separator(const char* arg);
to check if the argument is the separator or not.
Options loaded from config files were added before command line
arguments, and they were parsed together, which could interprete
the following:
option-a
option-b
as --option-a=--option-b if 'option-a' requires a value, and
caused confusing.
Because all options that requires a value are always given in
the form '--option=value', so it's an error if there is no
'=value' part for such an option read from config file.
This patch added a separator to separate the arguments from
config files and that from command line, so that they can be
handled differently. And report an error for options loaded
from config files that requires a value and is not given in the
form '--option=value'.