Merge branch 'ks/branch-set-upstream'

A test title has been reworded to clarify it.

* ks/branch-set-upstream:
  t3200: clarify description of --set-upstream test

t/t3200-branch.sh

@@ -885,7 +885,7 @@ test_expect_success 'test --unset-upstream on a particular branch' '
 	test_must_fail git config branch.my14.merge
 '
 
-test_expect_success '--set-upstream fails' '
+test_expect_success 'disabled option --set-upstream fails' '
     test_must_fail git branch --set-upstream origin/master
 '