tests: fix a spurious failure with older flex versions

See automake bug#11524 and bug#12836.

* t/lex-header.sh: Here, we use flex option '--header-file',
but that option is not supported by some older flex versions.
Simply skip this test if such an old flex version is detected.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/t/lex-header.sh b/t/lex-header.sh
index f8d7333e64e77f91acab6f488abc65fc73c4ea48..ad2976e35ef510a7e3bd54ef881d7300fde24775 100755 (executable)
--- a/t/lex-header.sh
+++ b/t/lex-header.sh
@@ -20,6 +20,12 @@
 required='cc flex'
 . ./defs || exit 1
 
+# Here, we need to use the use flex option '--header-file', but some
+# older flex versions don't support is (see automake bug#11524 and
+# bug#12836).  Skip this test if such an old flex version is detected.
+$LEX --help | grep '.*--header-file' \
+  || skip_ "flex doesn't support the --header-file' option"
+
 cat >> configure.ac << 'END'
 AC_PROG_CC
 AC_PROG_LEX