Previously, we'd try to put the stdout temp file in the same dir as the
target, if that dir exists. Otherwise we'd walk up the directory tree
looking for a good place. But this would go wrong if the directory we
chose got *deleted* during the run of the .do file.
Instead, we switch to an entirely new design: we use mkstemp() to
generate a temp file in the standard temp file location (probably
/tmp), then open it and immediately delete it, so the .do file can't
cause any unexpected behaviour. After the .do file exits, we use our
still-open fd to the stdout file to read the content back out.
In the old implementation, we also put the $3 in the "adjusted"
location that depended whether the target dir already existed, just for
consistency. But that was never necessary: we didn't create the $3
file, and if the .do script wants to write to $3, it should create the
target dir first anyway. So change it to *always* use a $3 temp
filename in the target dir, which is much simpler and so has fewer edge
cases.
Add t/202-del/deltest4 with some tests for all these edge cases.
Reported-by: Jeff Stearns <jeff.stearns@gmail.com>
d95277d121