[PATCH] WIP: provide relative lastmod sexp queries

[David Bremner <david@tethera.net>]

---

I haven't looked carefully at how much work it would be to add to the
infix parser yet. I suspect it means adding a new RangeProcessor class
modelled on ParseTimeRangeProcessor. Maybe some of the logic from
_parse_sexp_range could be shared with the other parser.

 lib/parse-sexp.cc              | 6 ++++++
 test/T570-revision-tracking.sh | 8 ++++++++
 2 files changed, 14 insertions(+)

diff --git a/lib/parse-sexp.cc b/lib/parse-sexp.cc
index 0f14d8b7..e9ef4268 100644
--- a/lib/parse-sexp.cc
+++ b/lib/parse-sexp.cc
@@ -575,6 +575,9 @@ _sexp_parse_range (notmuch_database_t *notmuch,  const _sexp_prefix_t *prefix,
 	    return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 	}
 
+	if (from_idx < 0)
+	    from_idx += notmuch_database_get_revision (notmuch, NULL);
+
 	try {
 	    if (EMPTY_STRING (to))
 		to_idx = LONG_MAX;
@@ -585,6 +588,9 @@ _sexp_parse_range (notmuch_database_t *notmuch,  const _sexp_prefix_t *prefix,
 	    return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 	}
 
+	if (to_idx < 0)
+	    to_idx += notmuch_database_get_revision (notmuch, NULL);
+
 	output = Xapian::Query (Xapian::Query::OP_VALUE_RANGE, NOTMUCH_VALUE_LAST_MOD,
 				Xapian::sortable_serialise (from_idx),
 				Xapian::sortable_serialise (to_idx));
diff --git a/test/T570-revision-tracking.sh b/test/T570-revision-tracking.sh
index e1cc684d..aaa45468 100755
--- a/test/T570-revision-tracking.sh
+++ b/test/T570-revision-tracking.sh
@@ -95,4 +95,12 @@ subtotal=$(notmuch count lastmod:..$lastmod)
 result=$(($subtotal == $total-1))
 test_expect_equal 1 "$result"
 
+if [ $NOTMUCH_HAVE_SFSEXP -eq 1 ]; then
+    test_begin_subtest 'exclude one message using negative lastmod (sexp)'
+    total=$(notmuch count '*')
+    notmuch tag +${RANDOM} id:4EFC743A.3060609@april.org
+    count=$(notmuch count --query=sexp '(lastmod -1 *)')
+    test_expect_equal 1 "$count"
+fi
+
 test_done
-- 
2.35.2