test_cmp expected actual
'
+test_expect_success 'diff --submodule with objects referenced by alternates' '
+ mkdir sub_alt &&
+ (cd sub_alt &&
+ git init &&
+ echo a >a &&
+ git add a &&
+ git commit -m a
+ ) &&
+ mkdir super &&
+ (cd super &&
+ git clone -s ../sub_alt sub &&
+ git init &&
+ git add sub &&
+ git commit -m "sub a"
+ ) &&
+ (cd sub_alt &&
+ sha1_before=$(git rev-parse --short HEAD)
+ echo b >b &&
+ git add b &&
+ git commit -m b
+ sha1_after=$(git rev-parse --short HEAD)
+ echo "Submodule sub $sha1_before..$sha1_after:
+ > b" >../expected
+ ) &&
+ (cd super &&
+ (cd sub &&
+ git fetch &&
+ git checkout origin/master
+ ) &&
+ git diff --submodule > ../actual
+ )
+ test_cmp expected actual
+'
+
test_done