in update_history(), add a check to make sure the parameter we pass to

renumber() isn't NULL, and update related comments


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@2979 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

src/files.c

@@ -449,7 +449,7 @@ void read_file(FILE *f, const char *filename)
     if (fileptr == NULL)
 	open_buffer("");
 
-    /* Did we try to insert a file of 0 bytes? */
+    /* Did we try to insert a file of zero bytes? */
     if (num_lines != 0) {
 	if (openfile->current != NULL) {
 	    fileptr->next = openfile->current;