2521. [bug] Improve epoll cross compilation support. [RT #19047]

CHANGES

+2521.	[bug]		Improve epoll cross compilation support. [RT #19047]
+
 2520.	[bug]		Update xml statistics version number to 2.0 as change
 			#2388 made the schema incompatible to the previous
 			version. [RT #19080]

configure.in

@@ -18,7 +18,7 @@ AC_DIVERT_PUSH(1)dnl
 esyscmd([sed "s/^/# /" COPYRIGHT])dnl
 AC_DIVERT_POP()dnl
 
-AC_REVISION($Revision: 1.461 $)
+AC_REVISION($Revision: 1.462 $)
 
 AC_INIT(lib/dns/name.c)
 AC_PREREQ(2.59)
@@ -367,10 +367,10 @@ AC_SUBST(ISC_PLATFORM_HAVEKQUEUE)
 # so we need to try running the code, not just test its existence.
 #
 AC_ARG_ENABLE(epoll,
-	[  --enable-epoll          use Linux epoll when available [[default=yes]]],
-	      want_epoll="$enableval",  want_epoll="yes")
+[  --enable-epoll          use Linux epoll when available [[default=auto]]],
+	      want_epoll="$enableval",  want_epoll="auto")
 case $want_epoll in
-yes)
+auto)
 	AC_MSG_CHECKING(epoll support)
 	AC_TRY_RUN([
 #include <sys/epoll.h>
@@ -385,6 +385,9 @@ int main() {
 	[AC_MSG_RESULT(no)
 	ISC_PLATFORM_HAVEEPOLL="#undef ISC_PLATFORM_HAVEEPOLL"])
 	;;
+yes)
+	ISC_PLATFORM_HAVEEPOLL="#define ISC_PLATFORM_HAVEEPOLL 1"
+	;;
 *)
 	ISC_PLATFORM_HAVEEPOLL="#undef ISC_PLATFORM_HAVEEPOLL"
 	;;