Fix the size() method to return the size of the file on Unix, not the

size of the mapped area.  This seems to be what the Windows version does.
This change requires keeping around the fd of the mapped file.

Modules/mmapmodule.c

@@ -29,6 +29,7 @@
 #ifdef UNIX
 #include <unistd.h>
 #include <sys/mman.h>
+#include <sys/stat.h>
 #endif
 
 #include <string.h>
@@ -49,7 +50,7 @@ typedef struct {
 #endif
 
 #ifdef UNIX
-  /* No Unix-specific information at this point in time */
+        int fd;
 #endif
 } mmap_object;
 
@@ -210,7 +211,7 @@ mmap_find_method (mmap_object *self,
 
 static PyObject *
 mmap_write_method (mmap_object * self,
-		       PyObject * args)
+		   PyObject * args)
 {
 	long length;
 	char * data;
@@ -264,7 +265,14 @@ mmap_size_method (mmap_object * self,
 #endif /* MS_WIN32 */
 
 #ifdef UNIX
-	return (Py_BuildValue ("l", self->size) );
+	{
+		struct stat buf;
+		if (-1 == fstat(self->fd, &buf)) {
+			PyErr_SetFromErrno(mmap_module_error);
+			return NULL;
+		}
+		return (Py_BuildValue ("l", buf.st_size) );
+	}
 #endif /* UNIX */
 }
 
@@ -717,6 +725,7 @@ new_mmap_object (PyObject * self, PyObject * args, PyObject *kwdict)
 	if (m_obj == NULL) {return NULL;}
 	m_obj->size = (size_t) map_size;
 	m_obj->pos = (size_t) 0;
+	m_obj->fd = fd;
 	m_obj->data = mmap(NULL, map_size, 
 			   prot, flags,
 			   fd, 0);