Secondary compile check for libevent min version = 1.4.3

ac/fpm_libevent.m4

@@ -1,4 +1,4 @@
-dnl @synopsis AC_LIB_EVENT([MINIMUM-VERSION])
+dnl @synopsis AC_LIB_EVENT([MINIMUM-VERSION],[REQUIRED-VERSION])
 dnl
 dnl Test for the libevent library of a particular version (or newer).
 dnl Source: http://svn.apache.org/repos/asf/incubator/thrift/trunk/aclocal/ax_lib_event.m4
@@ -142,13 +142,12 @@ PHP_ARG_WITH(libevent,,
 [  --with-libevent[=PATH]  Path to the libevent, needed for fpm SAPI [/usr/local]], yes, yes)
 
 if test "$PHP_LIBEVENT" != "no"; then
-	WANT_LIBEVENT_VERSION=ifelse([$1], ,1.2,$1)
+    LIBEVENT_MIN_VERSION=ifelse([$1], ,1.4.3,$1)
+    LIBEVENT_REQ_VERSION=ifelse([$2], ,1.4.11,$2)
 
 	# Default library search paths ($sys_lib_search_path_spec)
 	AC_LIBTOOL_SYS_DYNAMIC_LINKER
 
-	AC_MSG_CHECKING(for libevent >= $WANT_LIBEVENT_VERSION)
-
 	libevent_prefix=$ac_default_prefix
 	if test $prefix != "NONE" -a $prefix != "" -a $prefix != "no" ; then 
 		libevent_prefix=$prefix
@@ -158,12 +157,36 @@ if test "$PHP_LIBEVENT" != "no"; then
 		PHP_LIBEVENT=$libevent_prefix
     fi
 
+    AC_MSG_CHECKING(for libevent >= $LIBEVENT_REQ_VERSION)
     for ac_libevent_path in "" $PHP_LIBEVENT /usr /usr/local /opt /opt/local /opt/libevent ; do
+	  WANT_LIBEVENT_VERSION="$LIBEVENT_REQ_VERSION"
       AC_LIB_EVENT_DO_CHECK
       if test "$success" = "yes"; then
         break;
       fi
     done
+    if test "$success" = "no"; then
+
+		AC_MSG_RESULT(no)
+		AC_MSG_WARN([Could not find libevent $LIBEVENT_REQ_VERSION.])
+		AC_MSG_WARN([The use of earlier versions of libevent is not recommended])
+		AC_MSG_WARN([and can result in unspecified or unsupported behaviour.])
+
+        AC_MSG_CHECKING(for minimum libevent version >= $LIBEVENT_MIN_VERSION)
+        for ac_libevent_path in "" $PHP_LIBEVENT /usr /usr/local /opt /opt/local /opt/libevent ; do
+		  WANT_LIBEVENT_VERSION="$LIBEVENT_MIN_VERSION"
+	      AC_LIB_EVENT_DO_CHECK
+          if test "$success" = "yes"; then
+            break;
+          fi
+        done
+        if test "$success" = "no"; then
+		  AC_MSG_RESULT(no)
+          LIBEVENT_LIBS=""
+		  ac_have_libevent=no
+          AC_MSG_ERROR([Libevent minimum version >= $LIBEVENT_MIN_VERSION could not be found.])
+        fi
+	fi
 
 	if test "$ext_shared" = "yes"; then
 		if test -n "$ac_libevent_path"; then
@@ -190,11 +213,7 @@ if test "$PHP_LIBEVENT" != "no"; then
 		fi
 	fi
 
-	if test "$success" != "yes" ; then
-		AC_MSG_RESULT(no)
-		ac_have_libevent=no
-		AC_MSG_ERROR([Libevent $WANT_LIBEVENT_VERSION could not be found])
-	else
+	if test "$success" = "yes" ; then
 		AC_MSG_RESULT(yes)
 		ac_have_libevent=yes
 		AC_DEFINE(HAVE_LIBEVENT, 1, [define if libevent is available])

config.m4

@@ -10,7 +10,7 @@ if test "$PHP_FPM" != "no"; then
 	PHP_CONFIGURE_PART(Configuring fpm)
 
 	sinclude(sapi/fpm/ac/fpm_libevent.m4)
-		AC_LIB_EVENT([1.4.11])
+		AC_LIB_EVENT([1.4.3],[1.4.11])
 
 	sinclude(sapi/fpm/ac/fpm_checks.m4)
 		AC_FPM_CHECKS