Replace fixed-size character length of I/O lines to allocatable arrays

[perazz]

Description

fpm/src/fpm_filesystem.F90

Line 19 in 11e0a98

integer, parameter :: LINE_BUFFER_LEN = 1000

fpm's I/O routines depend on a 1000-sized character string, which is easily exceeded for example when large environment variables such as PATH are queried from the system.

An example of failed case CI action to this issue is https://github.com/fortran-lang/fpm/actions/runs/4948404487/jobs/8849071110

I propose replacing this approach with routines that only employ allocatable lenght character variables, so that lines with arbitrary size can be loaded without occurring in buffer overflows.

Expected Behaviour

Should never SEGFAULT

Version of fpm

0.8.1

Platform and Architecture

Windows

Additional Information

No response

[urbanjost]

Had some issues with github/git so need to confirm the intended PR is there; but it will be shortly if not. I think this removes the limit in the READs and clarifies a few other issues where the same variable was being used as a buffer size, a length limit on I/O, the maximum length of a filename, and was public in a few cases where it was not representing a global value; so I am pretty sure it resolves the limit you referred to and a few others.