fix(tvix): Use copy constructor to add strings to protos r/1886

Passing a string directly to add_paths like this causes the proto class
to take ownership over the string, meaning when it is destructed it
will *explicitly* free the string. When the string's actual owner (the
derivation struct) then goes out of scope it'll get freed again, causing
a double-free. This fixes that to instead use the copy constructor to
assign to a pointer to a new path, and covers the whole to_proto method
with a rapidcheck test.

Fixes: b/64
Change-Id: I84235bed9104ff430a0acf686d4a96f1e2e9a897
Reviewed-on: https://cl.tvl.fyi/c/depot/+/2106
Reviewed-by: tazjin <mail@tazj.in>
Tested-by: BuildkiteCI

0 files changed, 0 insertions, 0 deletions