Merge branch 'ab/test-env'

Many GIT_TEST_* environment variables control various aspects of
how our tests are run, but a few followed "non-empty is true, empty
or unset is false" while others followed the usual "there are a few
ways to spell true, like yes, on, etc., and also ways to spell
false, like no, off, etc." convention.

* ab/test-env:
  env--helper: mark a file-local symbol as static
  tests: make GIT_TEST_FAIL_PREREQS a boolean
  tests: replace test_tristate with "git env--helper"
  tests README: re-flow a previously changed paragraph
  tests: make GIT_TEST_GETTEXT_POISON a boolean
  t6040 test: stop using global "script" variable
  config.c: refactor die_bad_number() to not call gettext() early
  env--helper: new undocumented builtin wrapping git_env_*()
  config tests: simplify include cycle test

1 files changed, 8 insertions, 50 deletions

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 7308f67922..27b81276fc 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -309,7 +309,7 @@ test_unset_prereq () {
 }
 
 test_set_prereq () {
-	if test -n "$GIT_TEST_FAIL_PREREQS"
+	if test -n "$GIT_TEST_FAIL_PREREQS_INTERNAL"
 	then
 		case "$1" in
 		# The "!" case is handled below with
@@ -1050,62 +1050,20 @@ perl () {
 	command "$PERL_PATH" "$@" 2>&7
 } 7>&2 2>&4
 
-# Is the value one of the various ways to spell a boolean true/false?
-test_normalize_bool () {
-	git -c magic.variable="$1" config --bool magic.variable 2>/dev/null
-}
-
-# Given a variable $1, normalize the value of it to one of "true",
-# "false", or "auto" and store the result to it.
-#
-#     test_tristate GIT_TEST_HTTPD
-#
-# A variable set to an empty string is set to 'false'.
-# A variable set to 'false' or 'auto' keeps its value.
-# Anything else is set to 'true'.
-# An unset variable defaults to 'auto'.
-#
-# The last rule is to allow people to set the variable to an empty
-# string and export it to decline testing the particular feature
-# for versions both before and after this change.  We used to treat
-# both unset and empty variable as a signal for "do not test" and
-# took any non-empty string as "please test".
-
-test_tristate () {
-	if eval "test x\"\${$1+isset}\" = xisset"
-	then
-		# explicitly set
-		eval "
-			case \"\$$1\" in
-			'')	$1=false ;;
-			auto)	;;
-			*)	$1=\$(test_normalize_bool \$$1 || echo true) ;;
-			esac
-		"
-	else
-		eval "$1=auto"
-	fi
-}
-
 # Exit the test suite, either by skipping all remaining tests or by
-# exiting with an error. If "$1" is "auto", we then we assume we were
-# opportunistically trying to set up some tests and we skip. If it is
-# "true", then we report a failure.
+# exiting with an error. If our prerequisite variable $1 falls back
+# on a default assume we were opportunistically trying to set up some
+# tests and we skip. If it is explicitly "true", then we report a failure.
 #
 # The error/skip message should be given by $2.
 #
 test_skip_or_die () {
-	case "$1" in
-	auto)
+	if ! git env--helper --type=bool --default=false --exit-code $1
+	then
 		skip_all=$2
 		test_done
-		;;
-	true)
-		error "$2"
-		;;
-	*)
-		error "BUG: test tristate is '$1' (real error: $2)"
-	esac
+	fi
+	error "$2"
 }
 
 # The following mingw_* functions obey POSIX shell syntax, but are actually