i18n.txt

At the core level, git is character encoding agnostic.

 - The pathnames recorded in the index and in the tree objects
 are treated as uninterpreted sequences of non-NUL bytes.
 What readdir(2) returns are what are recorded and compared
 with the data git keeps track of, which in turn are expected
 to be what lstat(2) and creat(2) accepts. There is no such
 thing as pathname encoding translation.

 - The contents of the blob objects are uninterpreted sequence
 of bytes. There is no encoding translation at the core
 level.

 - The commit log messages are uninterpreted sequence of non-NUL
 bytes.

Although we encourage that the commit log messages are encoded
in UTF-8, both the core and git Porcelain are designed not to
force UTF-8 on projects. If all participants of a particular
project find it more convenient to use legacy encodings, git
does not forbid it. However, there are a few things to keep in
mind.

. `git-commit-tree` (hence, `git-commit` which uses it) issues
 an warning if the commit log message given to it does not look
 like a valid UTF-8 string, unless you explicitly say your
 project uses a legacy encoding. The way to say this is to
 have i18n.commitencoding in `.git/config` file, like this:
+
------------
[i18n]
commitencoding = ISO-8859-1
------------
+
Commit objects created with the above setting record the value
of `i18n.commitencoding` in its `encoding` header. This is to
help other people who look at them later. Lack of this header
implies that the commit log message is encoded in UTF-8.

. `git-log`, `git-show` and friends looks at the `encoding`
 header of a commit object, and tries to re-code the log
 message into UTF-8 unless otherwise specified. You can
 specify the desired output encoding with
 `i18n.logoutputencoding` in `.git/config` file, like this:
+
------------
[i18n]
logoutputencoding = ISO-8859-1
------------
+
If you do not have this configuration variable, the value of
`i18n.commitencoding` is used instead.

Note that we deliberately chose not to re-code the commit log
message when a commit is made to force UTF-8 at the commit
object level, because re-coding to UTF-8 is not necessarily a
reversible operation.