add test_requires readline

Author: rolandwalker

test/tools/libtest.sh

@@ -593,6 +593,22 @@ require_git_version()
 	fi
 }
 
+has_readline()
+{
+	# Test functionality, since there isn't a good way to inspect the binary.
+	# bug: no timeout
+	readline_exit_status=1
+	file readline_guard.script <<-EOF
+	:quit
+	EOF
+
+	TIG_NO_DISPLAY=1 TIG_SCRIPT=readline_guard.script tig status </dev/null >/dev/null 2>&1 || true
+	test -e .tig_history && readline_exit_status=0
+	rm -f -- readline_guard.script .tig_history
+
+	return "$readline_exit_status"
+}
+
 test_require()
 {
 	while [ $# -gt 0 ]; do
@@ -622,6 +638,11 @@ test_require()
 				test_skip "The test requires a '$feature' executable"
 			fi
 			;;
+		readline)
+			if ! has_readline; then
+				test_skip "The test requires a tig compiled with readline"
+			fi
+			;;
 		*)
 			test_skip "Unknown feature requirement: $feature"
 		esac