t/test_lib: avoid naked bash arrays in file_lineno

662f9cf (tests: when run in Bash, annotate test failures with file
name/line number, 2020-04-11), introduces a way to report the location
(file:lineno) of a failed test case by traversing the bash callstack.

The implementation requires bash and uses shell arrays and is therefore
protected by a guard but NetBSD sh will still have to parse the function
and therefore will result in:

  ** t0000-basic.sh ***
  ./test-lib.sh: 681: Syntax error: Bad substitution

Enclose the bash specific code inside an eval to avoid parsing errors in
the same way than 5826b7b (test-lib: check Bash version for '-x'
without using shell arrays, 2019-01-03)

Signed-off-by: Carlo Marcelo Arenas Belón <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: carenas

t/test-lib.sh

@@ -677,14 +677,16 @@ die () {
 
 file_lineno () {
 	test -z "$GIT_TEST_FRAMEWORK_SELFTEST" && test -n "$BASH" || return 0
-	local i
-	for i in ${!BASH_SOURCE[*]}
-	do
-		case $i,"${BASH_SOURCE[$i]##*/}" in
-		0,t[0-9]*.sh) echo "t/${BASH_SOURCE[$i]}:$LINENO: ${1+$1: }"; return;;
-		*,t[0-9]*.sh) echo "t/${BASH_SOURCE[$i]}:${BASH_LINENO[$(($i-1))]}: ${1+$1: }"; return;;
-		esac
-	done
+	eval '
+		local i
+		for i in ${!BASH_SOURCE[*]}
+		do
+			case $i,"${BASH_SOURCE[$i]##*/}" in
+			0,t[0-9]*.sh) echo "t/${BASH_SOURCE[$i]}:$LINENO: ${1+$1: }"; return;;
+			*,t[0-9]*.sh) echo "t/${BASH_SOURCE[$i]}:${BASH_LINENO[$(($i-1))]}: ${1+$1: }"; return;;
+			esac
+		done
+	'
 }
 
 GIT_EXIT_OK=