Fix expr error in Solaris 10 when using gcc.

diff --git a/configure.ac b/configure.ac
index 2941cd7..4754c03 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -269,11 +269,13 @@ if test "x$GCC" = "xyes"; then
        if $CC $CFLAGS -c -fpic -fexceptions -o conftest.o conftest.c > /dev/null 2>&1; then
            objdump -h conftest.o > conftest.dump 2>&1
            libffi_eh_frame_line=`grep -n eh_frame conftest.dump | cut -d: -f 1`
-           libffi_test_line=`expr $libffi_eh_frame_line + 1`p
-           sed -n $libffi_test_line conftest.dump > conftest.line
-           if grep READONLY conftest.line > /dev/null; then
-               libffi_cv_ro_eh_frame=yes
-           fi
+           if test "x$libffi_eh_frame_line" != "x"; then
+               libffi_test_line=`expr $libffi_eh_frame_line + 1`p
+               sed -n $libffi_test_line conftest.dump > conftest.line
+               if grep READONLY conftest.line > /dev/null; then
+                   libffi_cv_ro_eh_frame=yes
+               fi
+           fi
        fi
        rm -f conftest.*
       ])