* lib/Automake/VarDef.pm (append): Turn VAR_ASIS variables into VAR_PRETTY variables to work around make implementation with limited line length, such as OSF1/Tru64 make. * tests/longline.test: New file. * tests/Makefile.am (TESTS): Add it. * tests/pluseq3.test, tests/pluseq8.test: Adjust. Report from Simon Josefsson.