[PATCH] tests: A new test prereq for testing chmod -w as root

["Ævar Arnfjörð Bjarmason" <avarab@gmail.com>]

Some tests depend on not being able to read files after chmod -w. This
doesn't work when running the tests as root.

Change test-lib.sh to test if this works, and if so it sets a new
CHMOD_0000 test prerequisite. The tests that use this previously
failed when run under root.

There was already a test for this in t3600-rm.sh added by Junio C
Hamano in 2283645b85 in 2006. That check now uses the new CHMOD_0000
prerequisite.

There are also two other prerequisites, "POSIXPERM_AND_CHMOD_0000" and
"SYMLINKS_AND_CHMOD_0000". They're being used for tests that failed
and already depended on POSIXPERM or SYMLINKS. They're possibly
redundant, but I don't have access to a system without POSIX
permissions or symlinks so I couldn't test that.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
---
 t/t0001-init.sh             |    2 +-
 t/t0004-unwritable.sh       |    8 ++++----
 t/t1004-read-tree-m-u-wf.sh |    2 +-
 t/t3600-rm.sh               |   16 ----------------
 t/t3700-add.sh              |   10 +++++-----
 t/t7300-clean.sh            |    7 +++----
 t/t7508-status.sh           |    2 +-
 t/test-lib.sh               |   14 ++++++++++++++
 8 files changed, 29 insertions(+), 32 deletions(-)

diff --git a/t/t0001-init.sh b/t/t0001-init.sh
index 7c0a698..7c62582 100755
--- a/t/t0001-init.sh
+++ b/t/t0001-init.sh
@@ -301,7 +301,7 @@ test_expect_success 'init notices EEXIST (2)' '
 	)
 '
 
-test_expect_success POSIXPERM 'init notices EPERM' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'init notices EPERM' '
 	rm -fr newdir &&
 	(
 		mkdir newdir &&
diff --git a/t/t0004-unwritable.sh b/t/t0004-unwritable.sh
index 2342ac5..1299f52 100755
--- a/t/t0004-unwritable.sh
+++ b/t/t0004-unwritable.sh
@@ -15,7 +15,7 @@ test_expect_success setup '
 
 '
 
-test_expect_success POSIXPERM 'write-tree should notice unwritable repository' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'write-tree should notice unwritable repository' '
 
 	(
 		chmod a-w .git/objects .git/objects/?? &&
@@ -27,7 +27,7 @@ test_expect_success POSIXPERM 'write-tree should notice unwritable repository' '
 
 '
 
-test_expect_success POSIXPERM 'commit should notice unwritable repository' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'commit should notice unwritable repository' '
 
 	(
 		chmod a-w .git/objects .git/objects/?? &&
@@ -39,7 +39,7 @@ test_expect_success POSIXPERM 'commit should notice unwritable repository' '
 
 '
 
-test_expect_success POSIXPERM 'update-index should notice unwritable repository' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'update-index should notice unwritable repository' '
 
 	(
 		echo 6O >file &&
@@ -52,7 +52,7 @@ test_expect_success POSIXPERM 'update-index should notice unwritable repository'
 
 '
 
-test_expect_success POSIXPERM 'add should notice unwritable repository' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'add should notice unwritable repository' '
 
 	(
 		echo b >file &&
diff --git a/t/t1004-read-tree-m-u-wf.sh b/t/t1004-read-tree-m-u-wf.sh
index f19b4a2..ceb0fd4 100755
--- a/t/t1004-read-tree-m-u-wf.sh
+++ b/t/t1004-read-tree-m-u-wf.sh
@@ -177,7 +177,7 @@ test_expect_success SYMLINKS 'funny symlink in work tree' '
 
 '
 
-test_expect_success SYMLINKS 'funny symlink in work tree, un-unlink-able' '
+test_expect_success SYMLINKS_AND_CHMOD_0000 'funny symlink in work tree, un-unlink-able' '
 
 	rm -fr a b &&
 	git reset --hard &&
diff --git a/t/t3600-rm.sh b/t/t3600-rm.sh
index b514cbb..b26cabd 100755
--- a/t/t3600-rm.sh
+++ b/t/t3600-rm.sh
@@ -28,22 +28,6 @@ embedded' &&
      git commit -m 'add files with tabs and newlines'
 "
 
-# Determine rm behavior
-# Later we will try removing an unremovable path to make sure
-# git rm barfs, but if the test is run as root that cannot be
-# arranged.
-: >test-file
-chmod a-w .
-rm -f test-file 2>/dev/null
-if test -f test-file
-then
-	test_set_prereq RO_DIR
-else
-	skip_all='skipping removal failure test (perhaps running as root?)'
-fi
-chmod 775 .
-rm -f test-file
-
 test_expect_success \
     'Pre-check that foo exists and is in index before git rm foo' \
     '[ -f foo ] && git ls-files --error-unmatch foo'
diff --git a/t/t3700-add.sh b/t/t3700-add.sh
index 7d7140d..a0f3e7c 100755
--- a/t/t3700-add.sh
+++ b/t/t3700-add.sh
@@ -179,7 +179,7 @@ test_expect_success 'git add --refresh' '
 	test -z "`git diff-index HEAD -- foo`"
 '
 
-test_expect_success POSIXPERM 'git add should fail atomically upon an unreadable file' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'git add should fail atomically upon an unreadable file' '
 	git reset --hard &&
 	date >foo1 &&
 	date >foo2 &&
@@ -190,7 +190,7 @@ test_expect_success POSIXPERM 'git add should fail atomically upon an unreadable
 
 rm -f foo2
 
-test_expect_success POSIXPERM 'git add --ignore-errors' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'git add --ignore-errors' '
 	git reset --hard &&
 	date >foo1 &&
 	date >foo2 &&
@@ -201,7 +201,7 @@ test_expect_success POSIXPERM 'git add --ignore-errors' '
 
 rm -f foo2
 
-test_expect_success POSIXPERM 'git add (add.ignore-errors)' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'git add (add.ignore-errors)' '
 	git config add.ignore-errors 1 &&
 	git reset --hard &&
 	date >foo1 &&
@@ -212,7 +212,7 @@ test_expect_success POSIXPERM 'git add (add.ignore-errors)' '
 '
 rm -f foo2
 
-test_expect_success POSIXPERM 'git add (add.ignore-errors = false)' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'git add (add.ignore-errors = false)' '
 	git config add.ignore-errors 0 &&
 	git reset --hard &&
 	date >foo1 &&
@@ -223,7 +223,7 @@ test_expect_success POSIXPERM 'git add (add.ignore-errors = false)' '
 '
 rm -f foo2
 
-test_expect_success POSIXPERM '--no-ignore-errors overrides config' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 '--no-ignore-errors overrides config' '
        git config add.ignore-errors 1 &&
        git reset --hard &&
        date >foo1 &&
diff --git a/t/t7300-clean.sh b/t/t7300-clean.sh
index 7d8ed68..5533973 100755
--- a/t/t7300-clean.sh
+++ b/t/t7300-clean.sh
@@ -388,16 +388,15 @@ test_expect_success 'core.excludesfile' '
 
 '
 
-test_expect_success 'removal failure' '
+test_expect_success CHMOD_0000 'removal failure' '
 
 	mkdir foo &&
 	touch foo/bar &&
 	(exec <foo/bar &&
 	 chmod 0 foo &&
-	 test_must_fail git clean -f -d)
-
+	 test_must_fail git clean -f -d &&
+	 chmod 755 foo)
 '
-chmod 755 foo
 
 test_expect_success 'nested git work tree' '
 	rm -fr foo bar &&
diff --git a/t/t7508-status.sh b/t/t7508-status.sh
index a72fe3a..4f85db5 100755
--- a/t/t7508-status.sh
+++ b/t/t7508-status.sh
@@ -793,7 +793,7 @@ test_expect_success 'commit --dry-run submodule summary (--amend)' '
 	test_cmp expect output
 '
 
-test_expect_success POSIXPERM 'status succeeds in a read-only repository' '
+test_expect_success POSIXPERM_AND_CHMOD_0000 'status succeeds in a read-only repository' '
 	(
 		chmod a-w .git &&
 		# make dir1/tracked stat-dirty
diff --git a/t/test-lib.sh b/t/test-lib.sh
index e8f21d5..41052fb 100644
--- a/t/test-lib.sh
+++ b/t/test-lib.sh
@@ -886,3 +886,17 @@ test -z "$NO_PYTHON" && test_set_prereq PYTHON
 # test whether the filesystem supports symbolic links
 ln -s x y 2>/dev/null && test -h y 2>/dev/null && test_set_prereq SYMLINKS
 rm -f y
+
+# test whether we can make read-only files
+mkdir hla
+chmod -w hla
+touch hla/gh >/dev/null 2>&1
+if ! test -f hla/gh
+then
+    test_set_prereq CHMOD_0000
+    # A hack around not being able to supply more than one
+    # prerequisite in the test_* functions.
+    test_have_prereq POSIXPERM && test_set_prereq POSIXPERM_AND_CHMOD_0000
+    test_have_prereq SYMLINKS  && test_set_prereq SYMLINKS_AND_CHMOD_0000
+fi
+rm -rf hla
-- 
1.7.1