smudge = cat
------------------------
+For best results, `clean` should not alter its output further if it is
+run twice ("clean->clean" should be equivalent to "clean"), and
+multiple `smudge` commands should not alter `clean`'s output
+("smudge->smudge->clean" should be equivalent to "clean"). See the
+section on merging below.
+
+The "indent" filter is well-behaved in this regard: it will not modify
+input that is already correctly indented. In this case, the lack of a
+smudge filter means that the clean filter _must_ accept its own output
+without modifying it.
+
Interaction between checkin/checkout attributes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
with `text`, and then `ident` and fed to `filter`.
+Merging branches with differing checkin/checkout attributes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+If you have added attributes to a file that cause the canonical
+repository format for that file to change, such as adding a
+clean/smudge filter or text/eol/ident attributes, merging anything
+where the attribute is not in place would normally cause merge
+conflicts.
+
+To prevent these unnecessary merge conflicts, git can be told to run a
+virtual check-out and check-in of all three stages of a file when
+resolving a three-way merge by setting the `merge.renormalize`
+configuration variable. This prevents changes caused by check-in
+conversion from causing spurious merge conflicts when a converted file
+is merged with an unconverted file.
+
+As long as a "smudge->clean" results in the same output as a "clean"
+even on files that are already smudged, this strategy will
+automatically resolve all filter-related conflicts. Filters that do
+not act in this way may cause additional merge conflicts that must be
+resolved manually.
+
+
Generating diff text
~~~~~~~~~~~~~~~~~~~~