Fix typo in duplicate removal on archive, per discussion at http://tech.groups.yahoo.com/group/todotxt/message/3775

tests/t1900-archive.sh

@@ -0,0 +1,34 @@
+#!/bin/sh
+
+test_description='archive functionality
+
+Ensure we can append items successfully.
+'
+. ./test-lib.sh
+
+cat >> todo.txt<<EOF
+one
+two
+three
+one
+x done
+four
+EOF
+
+test_todo_session 'archive with duplicates' <<EOF
+>>> todo.sh archive
+x done
+TODO: $HOME/todo.txt archived.
+EOF
+
+test_todo_session 'list after archive' <<EOF
+>>> todo.sh ls
+4 four
+1 one
+3 three
+2 two
+--
+TODO: 4 of 4 tasks shown
+EOF
+
+test_done