Merge branch 'jk/test-chain-lint'

People often forget to chain the commands in their test together
with &&, leaving a failure from an earlier command in the test go
unnoticed.  The new GIT_TEST_CHAIN_LINT mechanism allows you to
catch such a mistake more easily.

* jk/test-chain-lint: (36 commits)
  t9001: drop save_confirm helper
  t0020: use test_* helpers instead of hand-rolled messages
  t: simplify loop exit-code status variables
  t: fix some trivial cases of ignored exit codes in loops
  t7701: fix ignored exit code inside loop
  t3305: fix ignored exit code inside loop
  t0020: fix ignored exit code inside loops
  perf-lib: fix ignored exit code inside loop
  t6039: fix broken && chain
  t9158, t9161: fix broken &&-chain in git-svn tests
  t9104: fix test for following larger parents
  t4104: drop hand-rolled error reporting
  t0005: fix broken &&-chains
  t7004: fix embedded single-quotes
  t0050: appease --chain-lint
  t9001: use test_when_finished
  t4117: use modern test_* helpers
  t6034: use modern test_* helpers
  t1301: use modern test_* helpers
  t0020: use modern test_* helpers
  ...

t/t6000-rev-list-misc.sh

@@ -42,7 +42,7 @@ test_expect_success 'rev-list --objects with pathspecs and copied files' '
 	test_tick &&
 	git commit -m that &&
 
-	ONE=$(git rev-parse HEAD:one)
+	ONE=$(git rev-parse HEAD:one) &&
 	git rev-list --objects HEAD two >output &&
 	grep "$ONE two/three" output &&
 	! grep one output
@@ -85,7 +85,7 @@ test_expect_success 'rev-list can show index objects' '
 	#   - we do not show the root tree; since we updated the index, it
 	#     does not have a valid cache tree
 	#
-	cat >expect <<-\EOF
+	cat >expect <<-\EOF &&
 	8e4020bb5a8d8c873b25de15933e75cc0fc275df one
 	d9d3a7417b9605cfd88ee6306b28dadc29e6ab08 only-in-index
 	9200b628cf9dc883a85a7abc8d6e6730baee589c two