pj_open_lib_ex() doesn't size check name

[abellgithub]

pj_open_lib_ex() references *name without checking that name is not null. It also attempts to read name[1] without checking that it's accessible.

[rouault]

I don't see this as a bug. This is part of the contract of the function that name must not be null. Like it is undefined behaviour if you do fopen(NULL, mode).
I've added an extra comment in the doc of pj_find_file() regarding that

[abellgithub]

That's fine. Also note that there's an issue with a null string ("").

[rouault]

there's an issue with a null string ("").

Ah, right, I missed initially the case of || (name[1] == ':' && strchr(dir_chars,name[2])) ). Will fix