maintainer-makefile: prohibit test x == x

* top/maint.mk (sc_prohibit_test_double_equal): New rule.
Based on a report by Matthias Bolte.

Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/ChangeLog b/ChangeLog
index 8a9d7b6..21677e2 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2010-11-12  Eric Blake  <eblake@redhat.com>
 
+       maintainer-makefile: prohibit test x == x
+       * top/maint.mk (sc_prohibit_test_double_equal): New rule.
+       Based on a report by Matthias Bolte.
+
        bootstrap: allow FreeBSD gzip
        * build-aux/bootstrap (get_version): Parse FreeBSD gzip version,
        which has no '.' and goes to stderr.

diff --git a/top/maint.mk b/top/maint.mk
index 181a96f..d51944b 100644 (file)
--- a/top/maint.mk
+++ b/top/maint.mk
@@ -817,6 +817,12 @@ sc_prohibit_test_minus_ao:
        halt='$(_ptm1); $(_ptm2)'                                       \
          $(_sc_search_regexp)
 
+# Avoid a test bashism.
+sc_prohibit_test_double_equal:
+       @prohibit='(\<test| \[+) .+ == '                                \
+       halt='use "test x = x", not "test x =''= x"'                    \
+         $(_sc_search_regexp)
+
 # Each program that uses proper_name_utf8 must link with one of the
 # ICONV libraries.  Otherwise, some ICONV library must appear in LDADD.
 # The perl -0777 invocation below extracts the possibly-multi-line