[repacker] add a couple more complex isolation tests.

src/hb-repacker.hh

@@ -865,7 +865,8 @@ static bool _process_overflows (const hb_vector_t<graph_t::overflow_record_t>& o
 inline void
 hb_resolve_overflows (const hb_vector_t<hb_serialize_context_t::object_t *>& packed,
                       hb_tag_t table_tag,
-                      hb_serialize_context_t* c) {
+                      hb_serialize_context_t* c,
+                      unsigned max_rounds = 10) {
   // Kahn sort is ~twice as fast as shortest distance sort and works for many fonts
   // so try it first to save time.
   graph_t sorted_graph (packed);
@@ -894,7 +895,7 @@ hb_resolve_overflows (const hb_vector_t<hb_serialize_context_t::object_t *>& pac
   // TODO(garretrieger): select a good limit for max rounds.
   while (!sorted_graph.in_error ()
          && sorted_graph.will_overflow (&overflows)
-         && round++ < 10) {
+         && round++ < max_rounds) {
     DEBUG_MSG (SUBSET_REPACK, nullptr, "=== Overflow resolution round %d ===", round);
     sorted_graph.print_overflows (overflows);
 

src/test-repacker.cc

@@ -143,6 +143,70 @@ populate_serializer_with_isolation_overflow (hb_serialize_context_t* c)
   c->end_serialize();
 }
 
+static void
+populate_serializer_with_isolation_overflow_complex (hb_serialize_context_t* c)
+{
+  std::string large_string(70000, 'a');
+  c->start_serialize<char> ();
+
+  unsigned obj_f = add_object ("f", 1, c);
+
+  start_object ("e", 1, c);
+  add_offset (obj_f, c);
+  unsigned obj_e = c->pop_pack ();
+
+  start_object ("c", 1, c);
+  add_offset (obj_e, c);
+  unsigned obj_c = c->pop_pack ();
+
+  start_object ("d", 1, c);
+  add_offset (obj_e, c);
+  unsigned obj_d = c->pop_pack ();
+
+  start_object (large_string.c_str(), 60000, c);
+  add_offset (obj_c, c);
+  add_offset (obj_d, c);
+  unsigned obj_b = c->pop_pack ();
+
+  start_object (large_string.c_str(), 10000, c);
+  add_offset (obj_d, c);
+  unsigned obj_g = c->pop_pack ();
+
+  start_object ("a", 1, c);
+  add_wide_offset (obj_b, c);
+  add_offset (obj_g, c);
+  c->pop_pack ();
+
+  c->end_serialize();
+}
+
+
+static void
+populate_serializer_with_isolation_overflow_spaces (hb_serialize_context_t* c)
+{
+  std::string large_string(70000, 'a');
+  c->start_serialize<char> ();
+
+  unsigned obj_d = add_object ("f", 1, c);
+  unsigned obj_e = add_object ("f", 1, c);
+
+  start_object (large_string.c_str(), 60000, c);
+  add_offset (obj_d, c);
+  unsigned obj_b = c->pop_pack ();
+
+  start_object (large_string.c_str(), 60000, c);
+  add_offset (obj_e, c);
+  unsigned obj_c = c->pop_pack ();
+
+
+  start_object ("a", 1, c);
+  add_wide_offset (obj_b, c);
+  add_wide_offset (obj_c, c);
+  c->pop_pack ();
+
+  c->end_serialize();
+}
+
 static void
 populate_serializer_complex_1 (hb_serialize_context_t* c)
 {
@@ -509,7 +573,7 @@ static void test_resolve_overflows_via_isolation ()
   hb_serialize_context_t out (out_buffer, buffer_size);
 
   assert (c.offset_overflow ());
-  hb_resolve_overflows (c.object_graph (), HB_TAG ('G', 'S', 'U', 'B'), &out);
+  hb_resolve_overflows (c.object_graph (), HB_TAG ('G', 'S', 'U', 'B'), &out, 0);
   assert (!out.offset_overflow ());
   hb_bytes_t result = out.copy_bytes ();
   assert (result.length == (1 + 10000 + 60000 + 1 + 1
@@ -520,11 +584,57 @@ static void test_resolve_overflows_via_isolation ()
   free (out_buffer);
 }
 
-// TODO(grieger): test for recursively duplicated nodes during isolation.
-// TODO(grieger): test that isolated subgraphs are packed tightly within the subgraph.
+static void test_resolve_overflows_via_isolation_with_recursive_duplication ()
+{
+  size_t buffer_size = 160000;
+  void* buffer = malloc (buffer_size);
+  hb_serialize_context_t c (buffer, buffer_size);
+  populate_serializer_with_isolation_overflow_complex (&c);
+  graph_t graph (c.object_graph ());
+
+  void* out_buffer = malloc (buffer_size);
+  hb_serialize_context_t out (out_buffer, buffer_size);
+
+  assert (c.offset_overflow ());
+  hb_resolve_overflows (c.object_graph (), HB_TAG ('G', 'S', 'U', 'B'), &out, 0);
+  assert (!out.offset_overflow ());
+  hb_bytes_t result = out.copy_bytes ();
+
+  unsigned expected_length = 8 + 10000 + 60000; // objects
+  expected_length += 4 + 2 * 9; // links
+  assert (result.length == expected_length);
+
+  result.fini ();
+  free (buffer);
+  free (out_buffer);
+}
+
+static void test_resolve_overflows_via_isolation_spaces ()
+{
+  size_t buffer_size = 160000;
+  void* buffer = malloc (buffer_size);
+  hb_serialize_context_t c (buffer, buffer_size);
+  populate_serializer_with_isolation_overflow_spaces (&c);
+  graph_t graph (c.object_graph ());
+
+  void* out_buffer = malloc (buffer_size);
+  hb_serialize_context_t out (out_buffer, buffer_size);
+
+  assert (c.offset_overflow ());
+  hb_resolve_overflows (c.object_graph (), HB_TAG ('G', 'S', 'U', 'B'), &out, 0);
+  assert (!out.offset_overflow ());
+  hb_bytes_t result = out.copy_bytes ();
+
+  unsigned expected_length = 3 + 2 * 60000; // objects
+  expected_length += 2 * 4 + 2 * 2; // links
+  assert (result.length == expected_length);
+
+  result.fini ();
+  free (buffer);
+  free (out_buffer);
+}
 
 // TODO(garretrieger): update will_overflow tests to check the overflows array.
-// TODO(garretrieger): add a test(s) using a real font.
 // TODO(garretrieger): add tests for priority raising.
 
 int
@@ -540,6 +650,8 @@ main (int argc, char **argv)
   test_resolve_overflows_via_sort ();
   test_resolve_overflows_via_duplication ();
   test_resolve_overflows_via_isolation ();
+  test_resolve_overflows_via_isolation_with_recursive_duplication ();
+  test_resolve_overflows_via_isolation_spaces ();
   test_duplicate_leaf ();
   test_duplicate_interior ();
 }