Merge branch 'tb/local-clone-race-doc' into maint

Doc update.

* tb/local-clone-race-doc:
  Documentation/git-clone.txt: document race with --local

Documentation/git-clone.txt

@@ -57,6 +57,10 @@ repository is specified as a URL, then this flag is ignored (and we
 never use the local optimizations).  Specifying `--no-local` will
 override the default when `/path/to/repo` is given, using the regular
 Git transport instead.
++
+*NOTE*: this operation can race with concurrent modification to the
+source repository, similar to running `cp -r src dst` while modifying
+`src`.
 
 --no-hardlinks::
 	Force the cloning process from a repository on a local