`os.write` with `createFolders = true` does not work if `perms` doesn't contain executable permission

[kiendang]

os.write(
  os.pwd / "folder/out.txt",
  "asdf",
  perms = os.PermSet.fromString("rw-r--r--"),
  createFolders = true
)

would result in

java.nio.file.AccessDeniedException: .../folder/out.txt
  sun.nio.fs.UnixException.translateToIOException(UnixException.java:90)
  sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:106)
  sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:111)
  sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:219)
  java.nio.file.Files.newByteChannel(Files.java:380)
  os.write$.write(ReadWriteOps.scala:65)
  os.write$.apply(ReadWriteOps.scala:78)
  ammonite.$sess.cmd9$.<clinit>(cmd9.sc:1)

because perms is also applied to os.makeDir.all

os-lib/os/src/ReadWriteOps.scala

Line 79 in 60d334d

if (createFolders) makeDir.all(target / RelPath.up, perms)

and directories require executable permission to be accessible. Thus writing to a non-executable file with createFolders = true like in the example doesn't work.

This affects write.outputStream, write.append, write.append.outputStream, write.over, write.over.outputStream as well.

perms should be omitted from os.makeDir.all.

[kiendang]

happy to submit a PR for this

[Avimitin]

Similar to this issue, os.copy will fall into java.nio.file.AccessDeniedException when copying directory and source directory is read-only. os-lib will copy a read-only directory as destination then try to copy file from source and write to that read-only directory.

[lefou]

I guess the perms parameter is underspecified. We need to decide whether it should also apply to createFolders or not.

If the answer is yes, we need to create special code to create the dirs and adapt the permissions afterward. If no, we should not forward the perms parameter to os.makeDir.all.

In any case, we also need to document it.