+
Version 4 performs a simple pathname compression that reduces index
size by 30%-50% on large repositories, which results in faster load
-time. Version 4 is relatively young (first released in in 1.8.0 in
+time. Version 4 is relatively young (first released in 1.8.0 in
October 2012). Other Git implementations such as JGit and libgit2
may not support it yet.
are used, the untracked cache is immediately added to or removed from
the index.
+Before 2.17, the untracked cache had a bug where replacing a directory
+with a symlink to another directory could cause it to incorrectly show
+files tracked by git as untracked. See the "status: add a failing test
+showing a core.untrackedCache bug" commit to git.git. A workaround for
+that is (and this might work for other undiscovered bugs in the
+future):
+
+----------------
+$ git -c core.untrackedCache=false status
+----------------
+
+This bug has also been shown to affect non-symlink cases of replacing
+a directory with a file when it comes to the internal structures of
+the untracked cache, but no case has been reported where this resulted in
+wrong "git status" output.
+
+There are also cases where existing indexes written by git versions
+before 2.17 will reference directories that don't exist anymore,
+potentially causing many "could not open directory" warnings to be
+printed on "git status". These are new warnings for existing issues
+that were previously silently discarded.
+
+As with the bug described above the solution is to one-off do a "git
+status" run with `core.untrackedCache=false` to flush out the leftover
+bad data.
+
File System Monitor
-------------------