Build: Disable xzdec, lzmadec, and lzmainfo when they cannot be built.
They all need decoder support and if that isn't available,
there's no point trying to build them.
diff --git a/configure.ac b/configure.ac
index 4ed12b4..6b4a810 100644
--- a/configure.ac
+++ b/configure.ac
@@ -416,18 +416,21 @@
AC_ARG_ENABLE([xzdec], [AS_HELP_STRING([--disable-xzdec],
[do not build xzdec])],
[], [enable_xzdec=yes])
+test "x$enable_decoders" = xno && enable_xzdec=no
AM_CONDITIONAL([COND_XZDEC], [test x$enable_xzdec != xno])
AC_ARG_ENABLE([lzmadec], [AS_HELP_STRING([--disable-lzmadec],
[do not build lzmadec
(it exists primarily for LZMA Utils compatibility)])],
[], [enable_lzmadec=yes])
+test "x$enable_decoder_lzma1" = xno && enable_lzmadec=no
AM_CONDITIONAL([COND_LZMADEC], [test x$enable_lzmadec != xno])
AC_ARG_ENABLE([lzmainfo], [AS_HELP_STRING([--disable-lzmainfo],
[do not build lzmainfo
(it exists primarily for LZMA Utils compatibility)])],
[], [enable_lzmainfo=yes])
+test "x$enable_decoder_lzma1" = xno && enable_lzmainfo=no
AM_CONDITIONAL([COND_LZMAINFO], [test x$enable_lzmainfo != xno])
AC_ARG_ENABLE([lzma-links], [AS_HELP_STRING([--disable-lzma-links],
