Update harfbuzz-ng to 0.9.27

third_party/harfbuzz-ng/src/hb-fallback-shape.cc

 /*
  * Copyright © 2011  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.
@@ skipping 77 matching lines @@
  * shaper
  */
 
 hb_bool_t
 _hb_fallback_shape (hb_shape_plan_t    *shape_plan HB_UNUSED,
                     hb_font_t          *font,
                     hb_buffer_t        *buffer,
                     const hb_feature_t *features HB_UNUSED,
                     unsigned int        num_features HB_UNUSED)
 {
+  /* TODO
+   *
+   * - Apply fallback kern.
+   * - Handle Variation Selectors?
+   * - Apply normalization?
+   *
+   * This will make the fallback shaper into a dumb "TrueType"
+   * shaper which many people unfortunately still request.
+   */
+
+  bool has_space;
   hb_codepoint_t space;
-  font->get_glyph (' ', 0, &space);
+  has_space = font->get_glyph (' ', 0, &space);
 
   buffer->clear_positions ();
 
   unsigned int count = buffer->len;
 
   for (unsigned int i = 0; i < count; i++)
   {
-    if (buffer->unicode->is_default_ignorable (buffer->info[i].codepoint)) {
+    if (has_space && buffer->unicode->is_default_ignorable (buffer->info[i].codepoint)) {
       buffer->info[i].codepoint = space;
       buffer->pos[i].x_advance = 0;
       buffer->pos[i].y_advance = 0;
       continue;
     }
     font->get_glyph (buffer->info[i].codepoint, 0, &buffer->info[i].codepoint);
     font->get_glyph_advance_for_direction (buffer->info[i].codepoint,
                                            buffer->props.direction,
                                            &buffer->pos[i].x_advance,
                                            &buffer->pos[i].y_advance);
     font->subtract_glyph_origin_for_direction (buffer->info[i].codepoint,
                                                buffer->props.direction,
                                                &buffer->pos[i].x_offset,
                                                &buffer->pos[i].y_offset);
   }
 
   if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
     hb_buffer_reverse (buffer);
 
   return true;
 }