Fail if the Ruby specified with --with-baseruby is too old

If the baseruby is explicitly specified, fail because the option is
not accepted if it does not meet the requirements.  If the option is
not specified, just display the warning and continue, in the hope that
it is not needed.

Follow up rubyGH-15809

Author: nobu

configure.ac

@@ -83,9 +83,17 @@ AC_ARG_WITH(baseruby,
 	],
 	[
 		AC_PATH_PROG([BASERUBY], [ruby], [false])
+		HAVE_BASERUBY=
 	])
-AS_IF([test "$HAVE_BASERUBY" != no], [
-    RUBYOPT=- $BASERUBY --disable=gems "${tooldir}/missing-baseruby.bat" --verbose || HAVE_BASERUBY=no
+AS_IF([test "$HAVE_BASERUBY" = no], [
+    # --without-baseruby
+], [error=`RUBYOPT=- $BASERUBY --disable=gems "${tooldir}/missing-baseruby.bat" --verbose 2>&1`], [
+    HAVE_BASERUBY=yes
+], [test "$HAVE_BASERUBY" = ""], [ # no --with-baseruby option
+    AC_MSG_WARN($error)            # just warn and continue
+    HAVE_BASERUBY=no
+], [                               # the ruby given by --with-baseruby is too old
+    AC_MSG_ERROR($error)           # bail out
 ])
 AS_IF([test "${HAVE_BASERUBY:=no}" != no], [
     AS_CASE(["$build_os"], [mingw*], [

win32/configure.bat

@@ -208,7 +208,7 @@ goto :loop ;
   shift
 goto :loop ;
 :baseruby
-  echo>> %config_make% HAVE_BASERUBY =
+  echo>> %config_make% HAVE_BASERUBY = yes
   echo>> %config_make% BASERUBY = %~2
   echo>>%confargs%  %1=%2 \
   shift

win32/setup.mak

@@ -24,6 +24,9 @@ MAKEFILE = Makefile
 CPU = PROCESSOR_LEVEL
 CC = $(CC) -nologo -source-charset:utf-8
 CPP = $(CC) -EP
+!if "$(HAVE_BASERUBY)" != "no" && "$(BASERUBY)" == ""
+BASERUBY = ruby
+!endif
 
 all: -prologue- -generic- -epilogue-
 i386-mswin32: -prologue- -i386- -epilogue-
@@ -46,8 +49,8 @@ prefix = $(prefix:\=/)
 <<
 	@type $(config_make) >>$(MAKEFILE)
 	@del $(config_make) > nul
-!if "$(HAVE_BASERUBY)" != "no" && "$(BASERUBY)" != ""
-	$(BASERUBY:/=\) "$(srcdir)/tool/missing-baseruby.bat" --verbose
+!if "$(HAVE_BASERUBY)" != "no"
+	@$(BASERUBY:/=\) "$(srcdir)/tool/missing-baseruby.bat" --verbose $(HAVE_BASERUBY:yes=|| exit )|| exit 0
 !endif
 !if "$(WITH_GMP)" != "no"
 	@($(CC) $(XINCFLAGS) <<conftest.c -link $(XLDFLAGS) gmp.lib > nul && (echo USE_GMP = yes) || exit /b 0) >>$(MAKEFILE)