Re: git with custom diff for commits

[Matthieu Moy <Matthieu.Moy@imag.fr>]

"Gerald Gutierrez" <ggmlfs@gmail.com> writes:

> if (user_redefined_changed)
>   if (user_defn_of_changed(work, head)) commit(work);
> else
>   if (builtin_changed(work, head)) commit(work);

That would lead to even less intuitive semantics.

Suppose your working tree has two changes, like

--- a/file
+++ b/file
@@ ... @@
-old ignored line
+new ignored line
@@ ... @@
-this is relevant
+change

What would git be supposed to do if you ignore anything containing
"ignored"?

If git commits, it will commit both changes. People checking-out the
new revision will get "new ignored line" in the file. So, a portion of
the diff that you wanted to ignore has actually gone into the
repository. IOW, whether "new ignored line" would go into the
repository depends on the presence of another unrelated change.

Perhaps you would have expected this, but I wouldn't, and I bet many
other users wouldn't either. And usually, when you can't have people
agree on a common reasonable semantics, the answer is "don't put it in
git, let people script the semantics they want".


Take another example : I use an external diff tool to work with
OpenDocument files. It converts them into text, and calls "git diff"
on them. My diff driver therefore ignores formatting changes. If I
made only content changes, I get no change with this diff driver.
Still, if I commit, I expect git to record my new formatting.

-- 
Matthieu