From 3394ec7048ce7c61e39e7d1f176e5d260e3273d1 Mon Sep 17 00:00:00 2001
From: Garret Rieger <grieger@google.com>
Date: Thu, 13 Oct 2022 23:02:54 +0000
Subject: [PATCH] [subset] use subset accelerator in tests.

This ensures it produces equivalent subsets as without the accelerator.
---
 perf/benchmark-subset.cc |  3 +++
 test/subset/run-tests.py |  1 +
 util/hb-subset.cc        | 45 +++++++++++++++++++++++++++++++++++++++-
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/perf/benchmark-subset.cc b/perf/benchmark-subset.cc
index c35f1109d..7c657880f 100644
--- a/perf/benchmark-subset.cc
+++ b/perf/benchmark-subset.cc
@@ -122,6 +122,9 @@ static hb_face_t* preprocess_face(hb_face_t* face)
                                      HB_SUBSET_SETS_NAME_ID));
 
   hb_subset_input_set_flags(input,
+                            HB_SUBSET_FLAGS_NOTDEF_OUTLINE |
+                            HB_SUBSET_FLAGS_GLYPH_NAMES |
+                            HB_SUBSET_FLAGS_RETAIN_GIDS |
                             HB_SUBSET_FLAGS_ADD_ACCELERATOR_DATA);
 
   hb_face_t* subset = hb_subset_or_fail (face, input);
diff --git a/test/subset/run-tests.py b/test/subset/run-tests.py
index a0c9e2885..6a2146dbe 100755
--- a/test/subset/run-tests.py
+++ b/test/subset/run-tests.py
@@ -52,6 +52,7 @@ def run_test (test, should_check_ots):
 	cli_args = ["--font-file=" + test.font_path,
 		    "--output-file=" + out_file,
 		    "--unicodes=%s" % test.unicodes (),
+		    "--preprocess-face",
 		    "--drop-tables+=DSIG",
 		    "--drop-tables-=sbix"]
 	cli_args.extend (test.get_profile_flags ())
diff --git a/util/hb-subset.cc b/util/hb-subset.cc
index b27b82f8a..438764878 100644
--- a/util/hb-subset.cc
+++ b/util/hb-subset.cc
@@ -32,6 +32,40 @@
 
 #include <hb-subset.h>
 
+static hb_face_t* preprocess_face(hb_face_t* face)
+{
+  hb_subset_input_t* input = hb_subset_input_create_or_fail ();
+
+  hb_set_clear (hb_subset_input_set(input, HB_SUBSET_SETS_UNICODE));
+  hb_set_invert (hb_subset_input_set(input, HB_SUBSET_SETS_UNICODE));
+
+  hb_set_clear (hb_subset_input_set(input,
+                                    HB_SUBSET_SETS_LAYOUT_FEATURE_TAG));
+  hb_set_invert (hb_subset_input_set(input,
+                                     HB_SUBSET_SETS_LAYOUT_FEATURE_TAG));
+
+  hb_set_clear (hb_subset_input_set(input,
+                                    HB_SUBSET_SETS_LAYOUT_SCRIPT_TAG));
+  hb_set_invert (hb_subset_input_set(input,
+                                     HB_SUBSET_SETS_LAYOUT_SCRIPT_TAG));
+
+  hb_set_clear (hb_subset_input_set(input,
+                                    HB_SUBSET_SETS_NAME_ID));
+  hb_set_invert (hb_subset_input_set(input,
+                                     HB_SUBSET_SETS_NAME_ID));
+
+  hb_subset_input_set_flags(input,
+                            HB_SUBSET_FLAGS_NOTDEF_OUTLINE |
+                            HB_SUBSET_FLAGS_GLYPH_NAMES |
+                            HB_SUBSET_FLAGS_RETAIN_GIDS |
+                            HB_SUBSET_FLAGS_ADD_ACCELERATOR_DATA);
+
+  hb_face_t* subset = hb_subset_or_fail (face, input);
+  hb_subset_input_destroy (input);
+
+  return subset;
+}
+
 /*
  * Command line interface to the harfbuzz font subsetter.
  */
@@ -103,6 +137,10 @@ struct subset_main_t : option_parser_t, face_options_t, output_options_t<false>
   {
     parse (argc, argv);
 
+    hb_face_t* orig_face = face;
+    if (preprocess)
+      orig_face = preprocess_face (face);
+
     hb_face_t *new_face = nullptr;
     for (unsigned i = 0; i < num_iterations; i++)
     {
@@ -119,6 +157,8 @@ struct subset_main_t : option_parser_t, face_options_t, output_options_t<false>
     }
 
     hb_face_destroy (new_face);
+    if (preprocess)
+      hb_face_destroy (orig_face);
 
     return success ? 0 : 1;
   }
@@ -160,6 +200,7 @@ struct subset_main_t : option_parser_t, face_options_t, output_options_t<false>
   public:
 
   unsigned num_iterations = 1;
+  gboolean preprocess;
   hb_subset_input_t *input = nullptr;
 };
 
@@ -657,7 +698,7 @@ parse_instance (const char *name,
 		GError    **error)
 {
   subset_main_t *subset_main = (subset_main_t *) data;
-  
+
   char *s = strtok((char *) arg, "=");
   while (s)
   {
@@ -915,6 +956,8 @@ subset_main_t::add_options ()
     {"no-prune-unicode-ranges",	0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_NO_PRUNE_UNICODE_RANGES>,	"Don't change the 'OS/2 ulUnicodeRange*' bits.", nullptr},
     {"glyph-names",		0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_GLYPH_NAMES>,		"Keep PS glyph names in TT-flavored fonts. ", nullptr},
     {"passthrough-tables",	0, G_OPTION_FLAG_NO_ARG, G_OPTION_ARG_CALLBACK, (gpointer) &set_flag<HB_SUBSET_FLAGS_PASSTHROUGH_UNRECOGNIZED>,	"Do not drop tables that the tool does not know how to subset.", nullptr},
+    {"preprocess-face",		0, 0, G_OPTION_ARG_NONE, &this->preprocess,
+     "If set preprocesses the face with the add accelerator option before actually subsetting.", nullptr},
     {nullptr}
   };
   add_group (flag_entries,