tests: avoid false-positive "make check" failure when perl is missing

* doc/Makefile.am (sc-lower-case-var): Skip this test when $(PERL)
is not usable.  Reported by Bruno Haible.

diff --git a/doc/Makefile.am b/doc/Makefile.am
index 6f466c58d5ca9fe74e3a3feb20d4af1b0a3defe4..888048396513c804abb6d84213f99adeea3b7c1d 100644 (file)
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -128,7 +128,7 @@ find_upper_case_var =               \
      }                         \
    END {$$m and (warn "$(ME): do not use upper case in \@var{...}\n"), exit 1}'
 sc-lower-case-var:
-       $(AM_V_GEN)$(PERL) -e 1 \
-         && $(PERL) -lne $(find_upper_case_var) $(srcdir)/*.texi
+       $(AM_V_GEN)$(PERL) -e 1 || { echo $@: skipping test; exit 0; }; \
+         $(PERL) -lne $(find_upper_case_var) $(srcdir)/*.texi
 
 check: check-texinfo