Merge branch 'jk/sanity' into maint

The tests that wanted to see that file becomes unreadable after
running "chmod a-r file", and the tests that wanted to make sure it
is not run as root, we used "can we write into the / directory?" as
a cheap substitute, but on some platforms that is not a good
heuristics.  The tests and their prerequisites have been updated to
check what they really require.

* jk/sanity:
test-lib.sh: set prerequisite SANITY by testing what we really need
tests: correct misuses of POSIXPERM
t/lib-httpd: switch SANITY check for NOT_ROOT

diff --combined t/test-lib.sh
index bb1402de944de11ee54a73dab7c33441ae1450c5,446d8d5a1da02587fc4e21d4eb276e848a87333c..c09677802cce067a946a2550cdd2d8ef33434e81
--- 1/t/test-lib.sh
--- 2/t/test-lib.sh
+++ b/t/test-lib.sh
@@@ -140,9 -140,6 +140,9 @@@ els
        }
  fi
  
 +: ${ASAN_OPTIONS=detect_leaks=0}
 +export ASAN_OPTIONS
 +
  # Protect ourselves from common misconfiguration to export
  # CDPATH into the environment
  unset CDPATH
@@@ -184,8 -181,16 +184,8 @@@ export _x05 _x40 _z40 LF u200
  # This test checks if command xyzzy does the right thing...
  # '
  # . ./test-lib.sh
 -[ "x$ORIGINAL_TERM" != "xdumb" ] && (
 -              TERM=$ORIGINAL_TERM &&
 -              export TERM &&
 -              [ -t 1 ] &&
 -              tput bold >/dev/null 2>&1 &&
 -              tput setaf 1 >/dev/null 2>&1 &&
 -              tput sgr0 >/dev/null 2>&1
 -      ) &&
 -      color=t
  
 +unset color
  while test "$#" -ne 0
  do
        case "$1" in
@@@ -232,10 -237,6 +232,10 @@@
        --root=*)
                root=$(expr "z$1" : 'z[^=]*=\(.*\)')
                shift ;;
 +      -x)
 +              trace=t
 +              verbose=t
 +              shift ;;
        *)
                echo "error: unknown test option '$1'" >&2; exit 1 ;;
        esac
@@@ -250,6 -251,40 +250,6 @@@ the
        verbose=t
  fi
  
 -if test -n "$color"
 -then
 -      say_color () {
 -              (
 -              TERM=$ORIGINAL_TERM
 -              export TERM
 -              case "$1" in
 -              error)
 -                      tput bold; tput setaf 1;; # bold red
 -              skip)
 -                      tput setaf 4;; # blue
 -              warn)
 -                      tput setaf 3;; # brown/yellow
 -              pass)
 -                      tput setaf 2;; # green
 -              info)
 -                      tput setaf 6;; # cyan
 -              *)
 -                      test -n "$quiet" && return;;
 -              esac
 -              shift
 -              printf "%s" "$*"
 -              tput sgr0
 -              echo
 -              )
 -      }
 -else
 -      say_color() {
 -              test -z "$1" && test -n "$quiet" && return
 -              shift
 -              printf "%s\n" "$*"
 -      }
 -fi
 -
  error () {
        say_color error "error: $*"
        GIT_EXIT_OK=t
@@@ -486,39 -521,10 +486,39 @@@ maybe_setup_valgrind () 
        fi
  }
  
 +# This is a separate function because some tests use
 +# "return" to end a test_expect_success block early
 +# (and we want to make sure we run any cleanup like
 +# "set +x").
 +test_eval_inner_ () {
 +      # Do not add anything extra (including LF) after '$*'
 +      eval "
 +              test \"$trace\" = t && set -x
 +              $*"
 +}
 +
  test_eval_ () {
 -      # This is a separate function because some tests use
 -      # "return" to end a test_expect_success block early.
 -      eval </dev/null >&3 2>&4 "$*"
 +      # We run this block with stderr redirected to avoid extra cruft
 +      # during a "-x" trace. Once in "set -x" mode, we cannot prevent
 +      # the shell from printing the "set +x" to turn it off (nor the saving
 +      # of $? before that). But we can make sure that the output goes to
 +      # /dev/null.
 +      #
 +      # The test itself is run with stderr put back to &4 (so either to
 +      # /dev/null, or to the original stderr if --verbose was used).
 +      {
 +              test_eval_inner_ "$@" </dev/null >&3 2>&4
 +              test_eval_ret_=$?
 +              if test "$trace" = t
 +              then
 +                      set +x
 +                      if test "$test_eval_ret_" != 0
 +                      then
 +                              say_color error >&4 "error: last command exited with \$?=$test_eval_ret_"
 +                      fi
 +              fi
 +      } 2>/dev/null
 +      return $test_eval_ret_
  }
  
  test_run_ () {
@@@ -529,8 -535,7 +529,8 @@@
        eval_ret=$?
        teardown_malloc_check
  
 -      if test -z "$immediate" || test $eval_ret = 0 || test -n "$expecting_failure"
 +      if test -z "$immediate" || test $eval_ret = 0 ||
 +         test -n "$expecting_failure" && test "$test_cleanup" != ":"
        then
                setup_malloc_check
                test_eval_ "$test_cleanup"
@@@ -642,7 -647,7 +642,7 @@@ test_done () 
                then
                        error "Can't use skip_all after running some tests"
                fi
 -              [ -z "$skip_all" ] || skip_all=" # SKIP $skip_all"
 +              test -z "$skip_all" || skip_all=" # SKIP $skip_all"
  
                if test $test_external_has_tap -eq 0
                then
@@@ -812,54 -817,7 +812,54 @@@ rm -fr "$TRASH_DIRECTORY" || 
  }
  
  HOME="$TRASH_DIRECTORY"
 -export HOME
 +GNUPGHOME="$HOME/gnupg-home-not-used"
 +export HOME GNUPGHOME
 +
 +# run the tput tests *after* changing HOME (in case ncurses needs
 +# ~/.terminfo for $TERM)
 +test -n "${color+set}" || test "x$ORIGINAL_TERM" != "xdumb" && (
 +              TERM=$ORIGINAL_TERM &&
 +              export TERM &&
 +              test -t 1 &&
 +              tput bold >/dev/null 2>&1 &&
 +              tput setaf 1 >/dev/null 2>&1 &&
 +              tput sgr0 >/dev/null 2>&1
 +      ) &&
 +      color=t
 +
 +if test -n "$color"
 +then
 +      say_color () {
 +              (
 +              TERM=$ORIGINAL_TERM
 +              export TERM
 +              case "$1" in
 +              error)
 +                      tput bold; tput setaf 1;; # bold red
 +              skip)
 +                      tput setaf 4;; # blue
 +              warn)
 +                      tput setaf 3;; # brown/yellow
 +              pass)
 +                      tput setaf 2;; # green
 +              info)
 +                      tput setaf 6;; # cyan
 +              *)
 +                      test -n "$quiet" && return;;
 +              esac
 +              shift
 +              printf "%s" "$*"
 +              tput sgr0
 +              echo
 +              )
 +      }
 +else
 +      say_color() {
 +              test -z "$1" && test -n "$quiet" && return
 +              shift
 +              printf "%s\n" "$*"
 +      }
 +fi
  
  if test -z "$TEST_NO_CREATE_REPO"
  then
@@@ -916,7 -874,7 +916,7 @@@ case $(uname -s) i
        # backslashes in pathspec are converted to '/'
        # exec does not inherit the PID
        test_set_prereq MINGW
 -      test_set_prereq NOT_CYGWIN
 +      test_set_prereq NATIVE_CRLF
        test_set_prereq SED_STRIPS_CR
        test_set_prereq GREP_STRIPS_CR
        GIT_TEST_CMP=mingw_test_cmp
@@@ -924,6 -882,7 +924,6 @@@
  *CYGWIN*)
        test_set_prereq POSIXPERM
        test_set_prereq EXECKEEPSPID
 -      test_set_prereq NOT_MINGW
        test_set_prereq CYGWIN
        test_set_prereq SED_STRIPS_CR
        test_set_prereq GREP_STRIPS_CR
@@@ -932,6 -891,8 +932,6 @@@
        test_set_prereq POSIXPERM
        test_set_prereq BSLASHPSPEC
        test_set_prereq EXECKEEPSPID
 -      test_set_prereq NOT_MINGW
 -      test_set_prereq NOT_CYGWIN
        ;;
  esac
  
@@@ -1031,9 -992,33 +1031,33 @@@ test_lazy_prereq USR_BIN_TIME 
        test -x /usr/bin/time
  '
  
- # When the tests are run as root, permission tests will report that
- # things are writable when they shouldn't be.
- test -w / || test_set_prereq SANITY
+ test_lazy_prereq NOT_ROOT '
+       uid=$(id -u) &&
+       test "$uid" != 0
+ '
+ 
+ # On a filesystem that lacks SANITY, a file can be deleted even if
+ # the containing directory doesn't have write permissions, or a file
+ # can be accessed even if the containing directory doesn't have read
+ # or execute permissions, causing our tests that validate that Git
+ # works sensibly in such situations.
+ test_lazy_prereq SANITY '
+       mkdir SANETESTD.1 SANETESTD.2 &&
+ 
+       chmod +w SANETESTD.1 SANETESTD.2 &&
+       >SANETESTD.1/x 2>SANETESTD.2/x &&
+       chmod -w SANETESTD.1 &&
+       chmod -rx SANETESTD.2 ||
+       error "bug in test sript: cannot prepare SANETESTD"
+ 
+       ! rm SANETESTD.1/x && ! test -f SANETESTD.2/x
+       status=$?
+ 
+       chmod +rwx SANETESTD.1 SANETESTD.2 &&
+       rm -rf SANETESTD.1 SANETESTD.2 ||
+       error "bug in test sript: cannot clean SANETESTD"
+       return $status
+ '
  
  GIT_UNZIP=${GIT_UNZIP:-unzip}
  test_lazy_prereq UNZIP '