Merge pull request #868 from googlefonts/post

[subset] Drop glyph names from post when subsetting.

src/hb-ot-post-table.hh

@@ -82,6 +82,28 @@ struct post
     return_trace (true);
   }
 
+  inline bool subset (hb_subset_plan_t *plan) const
+  {
+    unsigned int post_prime_length;
+    hb_blob_t *post_blob = OT::Sanitizer<post>().sanitize (hb_face_reference_table (plan->source, HB_OT_TAG_post));
+    hb_blob_t *post_prime_blob = hb_blob_create_sub_blob (post_blob, 0, post::static_size);
+    post *post_prime = (post *) hb_blob_get_data_writable (post_prime_blob, &post_prime_length);
+    hb_blob_destroy (post_blob);
+
+    if (unlikely (!post_prime || post_prime_length != post::static_size))
+    {
+      hb_blob_destroy (post_prime_blob);
+      DEBUG_MSG(SUBSET, nullptr, "Invalid source post table with length %d.", post_prime_length);
+      return false;
+    }
+
+    post_prime->version.major.set (3); // Version 3 does not have any glyph names.
+    bool result = hb_subset_plan_add_table (plan, HB_OT_TAG_post, post_prime_blob);
+    hb_blob_destroy (post_prime_blob);
+
+    return result;
+  }
+
   struct accelerator_t
   {
     inline void init (hb_face_t *face)

src/hb-subset.cc

@@ -41,6 +41,7 @@
 #include "hb-ot-hmtx-table.hh"
 #include "hb-ot-maxp-table.hh"
 #include "hb-ot-os2-table.hh"
+#include "hb-ot-post-table.hh"
 
 
 #ifndef HB_NO_VISIBILITY
@@ -270,6 +271,9 @@ _subset_table (hb_subset_plan_t *plan,
     case HB_OT_TAG_os2:
       result = _subset<const OT::os2> (plan);
       break;
+    case HB_OT_TAG_post:
+      result = _subset<const OT::post> (plan);
+      break;
     default:
       hb_blob_t *source_table = hb_face_reference_table(plan->source, tag);
       if (likely (source_table))

test/api/Makefile.am

@@ -36,6 +36,7 @@ TEST_PROGS = \
 	test-subset-hdmx \
 	test-subset-hmtx \
 	test-subset-os2 \
+	test-subset-post \
 	test-subset-vmtx \
 	test-unicode \
 	test-version \
@@ -47,6 +48,7 @@ test_subset_glyf_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 test_subset_hdmx_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 test_subset_hmtx_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 test_subset_os2_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
+test_subset_post_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 test_subset_vmtx_LDADD = $(LDADD) $(top_builddir)/src/libharfbuzz-subset.la
 
 test_unicode_CPPFLAGS = \

test/api/test-subset-post.c

@@ -0,0 +1,61 @@
+/*
+ * Copyright © 2018  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Google Author(s): Garret Rieger
+ */
+
+#include <stdbool.h>
+
+#include "hb-test.h"
+#include "hb-subset-test.h"
+
+/* Unit tests for hmtx subsetting */
+
+static void
+test_post_drops_glyph_names (void)
+{
+  hb_face_t *face_full = hb_subset_test_open_font ("fonts/Mplus1p-Regular.660E,6975,73E0,5EA6,8F38,6E05.ttf");
+  hb_face_t *face_subset = hb_subset_test_open_font ("fonts/Mplus1p-Regular.660E.ttf");
+
+  hb_set_t *codepoints = hb_set_create ();
+  hb_set_add (codepoints, 0x660E);
+
+  hb_face_t *face_full_subset = hb_subset_test_create_subset (face_full, hb_subset_test_create_input (codepoints));
+  hb_set_destroy (codepoints);
+
+  hb_subset_test_check (face_subset, face_full_subset, HB_TAG ('p','o','s','t'));
+
+  hb_face_destroy (face_full_subset);
+  hb_face_destroy (face_full);
+  hb_face_destroy (face_subset);
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+
+  hb_test_add (test_post_drops_glyph_names);
+
+  return hb_test_run();
+}