Merge branch 'nd/maint-sparse-errors'

* nd/maint-sparse-errors:
  Add explanation why we do not allow to sparse checkout to empty working tree
  sparse checkout: show error messages when worktree shaping fails

diff --cc t/t1011-read-tree-sparse-checkout.sh
index 018c3546b6f05228a20dfb5ec9364d0a1575e4ff,efcd8abd2f97458cfe06900d1723910bc59ac6dc..5c0053a20bf2fbf1dd466ace5dc933e38ce3544d
--- 1/t/t1011-read-tree-sparse-checkout.sh
--- 2/t/t1011-read-tree-sparse-checkout.sh
+++ b/t/t1011-read-tree-sparse-checkout.sh
@@@ -234,4 -234,19 +234,20 @@@ test_expect_success 'read-tree --reset 
        test_cmp empty result
  '
  
+ test_expect_success 'print errors when failed to update worktree' '
+       echo sub >.git/info/sparse-checkout &&
+       git checkout -f init &&
+       mkdir sub &&
+       touch sub/added sub/addedtoo &&
+       test_must_fail git checkout top 2>actual &&
+       cat >expected <<\EOF &&
+ error: The following untracked working tree files would be overwritten by checkout:
+       sub/added
+       sub/addedtoo
+ Please move or remove them before you can switch branches.
++Aborting
+ EOF
+       test_cmp expected actual
+ '
+ 
  test_done

diff --cc unpack-trees.c
Simple merge