--- configure.orig	2010-01-06 15:31:47.000000000 +0900
+++ configure	2010-01-06 15:34:50.000000000 +0900
@@ -3784,7 +3784,7 @@
   fi
 else
   if test "$GCC" = yes; then
-    CFLAGS="-O2"
+    CFLAGS="$CFLAGS"
   else
     CFLAGS=
   fi
@@ -5002,7 +5002,7 @@
 
 
 if test "x$GCC" = xyes; then
-	CFLAGS="-O2"
+	CFLAGS="$CFLAGS"
 fi
 # Check whether --enable-debug was given.
 if test "${enable_debug+set}" = set; then :
@@ -5259,7 +5259,7 @@
   fi
 else
   if test "$GXX" = yes; then
-    CXXFLAGS="-O2"
+    CXXFLAGS="$CXXFLAGS"
   else
     CXXFLAGS=
   fi
@@ -5399,7 +5399,7 @@
 
 
 if test "x$GXX" = xyes; then
-	CXXFLAGS="-O2"
+	CXXFLAGS="$CXXFLAGS"
 fi
 # Check whether --enable-debug was given.
 if test "${enable_debug+set}" = set; then :
@@ -8211,7 +8211,7 @@
   fi
 else
   if test "$GXX" = yes; then
-    CXXFLAGS="-O2"
+    CXXFLAGS="$CXXFLAGS"
   else
     CXXFLAGS=
   fi
@@ -15920,7 +15920,7 @@
 fi
 
 
-if test "x${ac_cv_have_x:0:10}" != "xhave_x=yes"; then
+if test "x${ac_cv_have_x+set}" = set; then
 	as_fn_error "X11 is missing but required." "$LINENO" 5
 fi