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
~~~~~~~~~~~~~~~~~~~~
Customizing word diff
^^^^^^^^^^^^^^^^^^^^^
-You can customize the rules that `git diff --color-words` uses to
+You can customize the rules that `git diff --word-diff` uses to
split words in a line, by specifying an appropriate regular expression
in the "diff.*.wordRegex" configuration variable. For example, in TeX
a backslash followed by a sequence of letters forms a command, but
should generate it separately and send it as a comment _in
addition to_ the usual binary diff that you might send.
+Because text conversion can be slow, especially when doing a
+large number of them with `git log -p`, git provides a mechanism
+to cache the output and use it in future diffs. To enable
+caching, set the "cachetextconv" variable in your diff driver's
+config. For example:
+
+------------------------
+[diff "jpg"]
+ textconv = exif
+ cachetextconv = true
+------------------------
+
+This will cache the result of running "exif" on each blob
+indefinitely. If you change the textconv config variable for a
+diff driver, git will automatically invalidate the cache entries
+and re-run the textconv filter. If you want to invalidate the
+cache manually (e.g., because your version of "exif" was updated
+and now produces better output), you can remove the cache
+manually with `git update-ref -d refs/notes/textconv/jpg` (where
+"jpg" is the name of the diff driver, as in the example above).
Performing a three-way merge
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
version (`%A`) and the other branches' version (`%B`). These
three tokens are replaced with the names of temporary files that
hold the contents of these versions when the command line is
-built.
+built. Additionally, %L will be replaced with the conflict marker
+size (see below).
The merge driver is expected to leave the result of the merge in
the file named with `%A` by overwriting it, and exit with zero