git-submodule foreach: Add $toplevel variable

[git.git] / Documentation / gitattributes.txt

diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index d892e642eded92fd0409e39fc34c005f88bc4a9b..0523a576989dfb717be06af04c4be22a5a8eafd6 100644 (file)
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -360,7 +360,7 @@ patterns are available:
 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
@@ -414,6 +414,26 @@ because it quickly conveys the changes you have made), you
 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
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~