bug#30785: Man pages truncated, repeated

[Ludovic Courtès]

Danny Milosavljevic <address@hidden> skribis:

> On Mon, 14 Jan 2019 18:48:53 +0100
> Danny Milosavljevic <address@hidden> wrote:
>
>> set_current_prefix() searches for the current program executable file in 
>> $PATH,
>> and it can fail and return 0. 
>> 
>> In that case, relocatep will probably segfault at the location marked below:
>> 
>> >   char *relocated_path = new char[curr_prefix_len + relative_path_len + 1];
>> >   strcpy(relocated_path, curr_prefix);  
>>                            ^^^^^^^^^^^
>
> This probably happens when argv[0] is not an absolute path, but still the 
> program
> somehow got started, but it is not found in $PATH either.

The ‘set_current_prefix’ logic is extremely fragile; it should readlink
from /proc/self/exe on GNU/Linux.

But in our case, no relocation happens, so we can just patch it to do:

  void set_current_prefix (void)
  {
    curr_prefix = "/gnu/store/…";
  }

Ludo’.