[subset] Fix infinite loop in there are more then 32 tables.

src/hb-subset.cc

@@ -359,6 +359,7 @@ hb_subset (hb_face_t *source,
         continue;
       }
       success = success && _subset_table (plan, tag);
+      offset += count;
     }
   } while (count == ARRAY_LENGTH (table_tags));
 

test/api/Makefile.am

@@ -31,6 +31,7 @@ TEST_PROGS = \
 	test-object \
 	test-set \
 	test-shape \
+	test-subset \
 	test-subset-cmap \
 	test-subset-glyf \
 	test-subset-hdmx \

test/api/test-subset.c

+/*
+ * 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 "hb-test.h"
+#include "hb-subset-test.h"
+
+/* Unit tests for hb-subset-glyf.h */
+
+static void
+test_subset_32_tables (void)
+{
+  hb_face_t *face = hb_subset_test_open_font("fonts/oom-6ef8c96d3710262511bcc730dce9c00e722cb653");
+
+  hb_subset_input_t *input = hb_subset_input_create_or_fail ();
+  hb_set_t *codepoints = hb_subset_input_unicode_set (input);
+  hb_set_add (codepoints, 'a');
+  hb_set_add (codepoints, 'b');
+  hb_set_add (codepoints, 'c');
+
+  hb_subset_profile_t *profile = hb_subset_profile_create();
+  hb_face_t *subset = hb_subset (face, profile, input);
+  g_assert (subset);
+  g_assert (subset != hb_face_get_empty ());
+
+  hb_subset_input_destroy (input);
+  hb_subset_profile_destroy (profile);
+  hb_face_destroy (subset);
+  hb_face_destroy (face);
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+
+  hb_test_add (test_subset_32_tables);
+
+  return hb_test_run();
+}