+dnl Check to see if lseek64() is declared in unistd.h. Glibc's header files
+dnl are so convoluted that I can't tell whether it will always be defined,
+dnl and if it isn't defined while lseek64 is defined in the library,
+dnl disaster will strike.
+dnl
+dnl Warning! Use of --enable-gcc-wall may throw off this test.
+dnl
+dnl
+AC_MSG_CHECKING(whether lseek64 declared in unistd.h)
+AC_CACHE_VAL(e2fsprogs_cv_have_lseek64_prototype,
+ AC_TRY_COMPILE(
+[#define _LARGEFILE_SOURCE
+#define _LARGEFILE64_SOURCE
+#include <unistd.h>], [extern int lseek64(int);],
+ [e2fsprogs_cv_have_lseek64_prototype=no],
+ [e2fsprogs_cv_have_lseek64_prototype=yes]))
+AC_MSG_RESULT($e2fsprogs_cv_have_lseek64_prototype)
+if test "$e2fsprogs_cv_have_lseek64_prototype" = yes; then
+ AC_DEFINE(HAVE_LSEEK64_PROTOTYPE)
+fi
+dnl