Include src/tests in the distribution tarball

and add a configure option for building them (default: off).
This patch fixes an error when configuring the tarball, where configure complained it cannot find
src/tests/Makefile.in.

configure.in

@@ -308,6 +308,22 @@ AC_ARG_ENABLE(debug,
 AC_SUBST(DEBUG)
 CXXFLAGS="$CXXFLAGS $DEBUG"
 
+dnl Check whether to build test programs
+AC_MSG_CHECKING([whether to build test programs])
+AC_ARG_ENABLE(test,
+  [  --enable-test           build programs used in testing fluxbox ([default=no])],
+  if test x$enableval = "xyes"; then
+    AC_MSG_RESULT([yes])
+    TEST=yes
+  else
+    AC_MSG_RESULT([no])
+    TEST=no
+  fi,
+  AC_MSG_RESULT([no])
+  TEST=no
+)
+AM_CONDITIONAL(TEST, test x$TEST = xyes)
+
 dnl Check whether to include native language support (i18n)
 AC_MSG_CHECKING([whether to include NLS support])
 AC_ARG_ENABLE(nls,

src/Makefile.am

@@ -23,7 +23,11 @@
 # DEALINGS IN THE SOFTWARE.
 
 
-SUBDIRS= FbTk
+if TEST
+BUILD_TEST= tests
+endif
+SUBDIRS= FbTk $(BUILD_TEST)
+
 DEFAULT_MENU=@DEFAULT_MENU@
 DEFAULT_STYLE=@DEFAULT_STYLE@
 DEFAULT_KEYSFILE=@DEFAULT_KEYS@