git-rebase is ignoring working-tree-encoding

["Adrián Gimeno Balaguer" <adrigibal@gmail.com>]

I’m attempting to perform fixups via git-rebase of UTF-16 LE files
(the project I’m working on requires that exact encoding on certain
files). When the rebase is complete, Git changes that file’s encoding
to UTF-16 BE. I have been using the newer working-tree-encoding
attribute in .gitattributes. I’m using Git for Windows.

$ git version
git version 2.19.1.windows.1

Here is a sample UTF-16 LE file (with BOM and LF endings) with
following atributes in .gitattributes:

test.txt eol=lf -text working-tree-encoding=UTF-16

I put eol=lf and -text to tell Git to not change the encoding of the
file on checkout, but that doesn’t even help. Asides, the newer
working-tree-encoding allows me to view human-readable diffs of that
file (in GitHub Desktop and Git Bash). Now, note that doing for
example consecutive commits to the same file does not affect the
UTF-16 LE encoding. And before I discovered this attribute, the whole
thing was even worse when squash/fixup rebasing, as Git would modify
the file with Chinese characters (when manually setting it as text via
.gitattributes).

So, again the problem with the exposed .gitattributes line is that
after fixup rebasing, UTF-16 LE files encoding change to UTF-16 BE.

For long, I have been working with the involved UTF-16 LE files set as
binary via .gitattributes (e.g. “test.txt binary”), so that Git would
not modify the file encoding, but this doesn’t allow me to view the
diffs upon changes in GitHub Desktop, which I want (and neither via
git diff).