or (2) match B.
------------------------------------------------------------------
15 exists O==A O==B take B must match A if exists.
+ ------------------------------------------------------------------
+ 16 exists O==A O==B barf must match A if exists.
+ *multi* in one in another
-------------------------------------------------------------------
Note: if we want to implement 2ALT and 3ALT we need to be careful.
git-update-index --add NN &&
git-read-tree -m $tree_O $tree_A $tree_B"
+# #16
+test_expect_success \
+ '16 - A matches in one and B matches in another.' \
+ 'rm -f .git/index F16 &&
+ echo F16 >F16 &&
+ git-update-index --add F16 &&
+ tree0=`git-write-tree` &&
+ echo E16 >F16 &&
+ git-update-index F16 &&
+ tree1=`git-write-tree` &&
+ git-read-tree -m $tree0 $tree1 $tree1 $tree0 &&
+ git-ls-files --stage'
+
test_done