Roll harfbuzz-ng to 1.0.5

third_party/harfbuzz-ng/src/hb-ot-layout-gpos-table.hh

 /*
  * Copyright © 2007,2008,2009,2010  Red Hat, Inc.
  * Copyright © 2010,2012,2013  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
@@ skipping 163 matching lines @@
   public:
 
   inline bool has_device (void) const {
     unsigned int format = *this;
     return (format & devices) != 0;
   }
 
   inline bool sanitize_value (hb_sanitize_context_t *c, const void *base, const Value *values) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_range (values, get_size ()) && (!has_device () || sanitize_value_devices (c, base, values)));
+    return_trace (c->check_range (values, get_size ()) && (!has_device () || sanitize_value_devices (c, base, values)));
   }
 
   inline bool sanitize_values (hb_sanitize_context_t *c, const void *base, const Value *values, unsigned int count) const
   {
     TRACE_SANITIZE (this);
     unsigned int len = get_len ();
 
-    if (!c->check_array (values, get_size (), count)) return TRACE_RETURN (false);
+    if (!c->check_array (values, get_size (), count)) return_trace (false);
 
-    if (!has_device ()) return TRACE_RETURN (true);
+    if (!has_device ()) return_trace (true);
 
     for (unsigned int i = 0; i < count; i++) {
       if (!sanitize_value_devices (c, base, values))
-        return TRACE_RETURN (false);
+        return_trace (false);
       values += len;
     }
 
-    return TRACE_RETURN (true);
+    return_trace (true);
   }
 
   /* Just sanitize referenced Device tables.  Doesn't check the values themselves. */
   inline bool sanitize_values_stride_unsafe (hb_sanitize_context_t *c, const void *base, const Value *values, unsigned int count, unsigned int stride) const
   {
     TRACE_SANITIZE (this);
 
-    if (!has_device ()) return TRACE_RETURN (true);
+    if (!has_device ()) return_trace (true);
 
     for (unsigned int i = 0; i < count; i++) {
       if (!sanitize_value_devices (c, base, values))
-        return TRACE_RETURN (false);
+        return_trace (false);
       values += stride;
     }
 
-    return TRACE_RETURN (true);
+    return_trace (true);
   }
 };
 
 
 struct AnchorFormat1
 {
   inline void get_anchor (hb_font_t *font, hb_codepoint_t glyph_id HB_UNUSED,
                           hb_position_t *x, hb_position_t *y) const
   {
       *x = font->em_scale_x (xCoordinate);
       *y = font->em_scale_y (yCoordinate);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this));
+    return_trace (c->check_struct (this));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 1 */
   SHORT         xCoordinate;            /* Horizontal value--in design units */
   SHORT         yCoordinate;            /* Vertical value--in design units */
   public:
   DEFINE_SIZE_STATIC (6);
 };
 
 struct AnchorFormat2
 {
   inline void get_anchor (hb_font_t *font, hb_codepoint_t glyph_id,
                           hb_position_t *x, hb_position_t *y) const
   {
       unsigned int x_ppem = font->x_ppem;
       unsigned int y_ppem = font->y_ppem;
       hb_position_t cx, cy;
       hb_bool_t ret;
 
       ret = (x_ppem || y_ppem) &&
              font->get_glyph_contour_point_for_origin (glyph_id, anchorPoint, HB_DIRECTION_LTR, &cx, &cy);
       *x = ret && x_ppem ? cx : font->em_scale_x (xCoordinate);
       *y = ret && y_ppem ? cy : font->em_scale_y (yCoordinate);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this));
+    return_trace (c->check_struct (this));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 2 */
   SHORT         xCoordinate;            /* Horizontal value--in design units */
   SHORT         yCoordinate;            /* Vertical value--in design units */
   USHORT        anchorPoint;            /* Index to glyph contour point */
   public:
   DEFINE_SIZE_STATIC (8);
 };
 
 struct AnchorFormat3
 {
   inline void get_anchor (hb_font_t *font, hb_codepoint_t glyph_id HB_UNUSED,
                           hb_position_t *x, hb_position_t *y) const
   {
       *x = font->em_scale_x (xCoordinate);
       *y = font->em_scale_y (yCoordinate);
 
       if (font->x_ppem)
         *x += (this+xDeviceTable).get_x_delta (font);
       if (font->y_ppem)
         *y += (this+yDeviceTable).get_x_delta (font);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this) && xDeviceTable.sanitize (c, this) && yDeviceTable.sanitize (c, this));
+    return_trace (c->check_struct (this) && xDeviceTable.sanitize (c, this) && yDeviceTable.sanitize (c, this));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 3 */
   SHORT         xCoordinate;            /* Horizontal value--in design units */
   SHORT         yCoordinate;            /* Vertical value--in design units */
   OffsetTo<Device>
                 xDeviceTable;           /* Offset to Device table for X
                                          * coordinate-- from beginning of
                                          * Anchor table (may be NULL) */
@@ skipping 15 matching lines @@
     case 1: u.format1.get_anchor (font, glyph_id, x, y); return;
     case 2: u.format2.get_anchor (font, glyph_id, x, y); return;
     case 3: u.format3.get_anchor (font, glyph_id, x, y); return;
     default:                                             return;
     }
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    if (!u.format.sanitize (c)) return TRACE_RETURN (false);
+    if (!u.format.sanitize (c)) return_trace (false);
     switch (u.format) {
-    case 1: return TRACE_RETURN (u.format1.sanitize (c));
-    case 2: return TRACE_RETURN (u.format2.sanitize (c));
-    case 3: return TRACE_RETURN (u.format3.sanitize (c));
-    default:return TRACE_RETURN (true);
+    case 1: return_trace (u.format1.sanitize (c));
+    case 2: return_trace (u.format2.sanitize (c));
+    case 3: return_trace (u.format3.sanitize (c));
+    default:return_trace (true);
     }
   }
 
   protected:
   union {
   USHORT                format;         /* Format identifier */
   AnchorFormat1         format1;
   AnchorFormat2         format2;
   AnchorFormat3         format3;
   } u;
   public:
   DEFINE_SIZE_UNION (2, format);
 };
 
 
 struct AnchorMatrix
 {
   inline const Anchor& get_anchor (unsigned int row, unsigned int col, unsigned int cols, bool *found) const {
     *found = false;
     if (unlikely (row >= rows || col >= cols)) return Null(Anchor);
     *found = !matrixZ[row * cols + col].is_null ();
     return this+matrixZ[row * cols + col];
   }
 
   inline bool sanitize (hb_sanitize_context_t *c, unsigned int cols) const
   {
     TRACE_SANITIZE (this);
-    if (!c->check_struct (this)) return TRACE_RETURN (false);
-    if (unlikely (rows > 0 && cols >= ((unsigned int) -1) / rows)) return TRACE_RETURN (false);
+    if (!c->check_struct (this)) return_trace (false);
+    if (unlikely (rows > 0 && cols >= ((unsigned int) -1) / rows)) return_trace (false);
     unsigned int count = rows * cols;
-    if (!c->check_array (matrixZ, matrixZ[0].static_size, count)) return TRACE_RETURN (false);
+    if (!c->check_array (matrixZ, matrixZ[0].static_size, count)) return_trace (false);
     for (unsigned int i = 0; i < count; i++)
-      if (!matrixZ[i].sanitize (c, this)) return TRACE_RETURN (false);
-    return TRACE_RETURN (true);
+      if (!matrixZ[i].sanitize (c, this)) return_trace (false);
+    return_trace (true);
   }
 
   USHORT        rows;                   /* Number of rows */
   protected:
   OffsetTo<Anchor>
                 matrixZ[VAR];           /* Matrix of offsets to Anchor tables--
                                          * from beginning of AnchorMatrix table */
   public:
   DEFINE_SIZE_ARRAY (2, matrixZ);
 };
 
 
 struct MarkRecord
 {
   friend struct MarkArray;
 
   inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this) && markAnchor.sanitize (c, base));
+    return_trace (c->check_struct (this) && markAnchor.sanitize (c, base));
   }
 
   protected:
   USHORT        klass;                  /* Class defined for this mark */
   OffsetTo<Anchor>
                 markAnchor;             /* Offset to Anchor table--from
                                          * beginning of MarkArray table */
   public:
   DEFINE_SIZE_STATIC (4);
 };
 
 struct MarkArray : ArrayOf<MarkRecord>  /* Array of MarkRecords--in Coverage order */
 {
   inline bool apply (hb_apply_context_t *c,
                      unsigned int mark_index, unsigned int glyph_index,
                      const AnchorMatrix &anchors, unsigned int class_count,
                      unsigned int glyph_pos) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
     const MarkRecord &record = ArrayOf<MarkRecord>::operator[](mark_index);
     unsigned int mark_class = record.klass;
 
     const Anchor& mark_anchor = this + record.markAnchor;
     bool found;
     const Anchor& glyph_anchor = anchors.get_anchor (glyph_index, mark_class, class_count, &found);
     /* If this subtable doesn't have an anchor for this base and this class,
      * return false such that the subsequent subtables have a chance at it. */
-    if (unlikely (!found)) return TRACE_RETURN (false);
+    if (unlikely (!found)) return_trace (false);
 
     hb_position_t mark_x, mark_y, base_x, base_y;
 
     mark_anchor.get_anchor (c->font, buffer->cur().codepoint, &mark_x, &mark_y);
     glyph_anchor.get_anchor (c->font, buffer->info[glyph_pos].codepoint, &base_x, &base_y);
 
     hb_glyph_position_t &o = buffer->cur_pos();
     o.x_offset = base_x - mark_x;
     o.y_offset = base_y - mark_y;
     o.attach_lookback() = buffer->idx - glyph_pos;
 
     buffer->idx++;
-    return TRACE_RETURN (true);
+    return_trace (true);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (ArrayOf<MarkRecord>::sanitize (c, this));
+    return_trace (ArrayOf<MarkRecord>::sanitize (c, this));
   }
 };
 
 
 /* Lookups */
 
 struct SinglePosFormat1
 {
   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
     (this+coverage).add_coverage (c->input);
   }
 
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
     unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint);
-    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
+    if (likely (index == NOT_COVERED)) return_trace (false);
 
     valueFormat.apply_value (c->font, c->direction, this,
                              values, buffer->cur_pos());
 
     buffer->idx++;
-    return TRACE_RETURN (true);
+    return_trace (true);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this)
-        && coverage.sanitize (c, this)
-        && valueFormat.sanitize_value (c, this, values));
+    return_trace (c->check_struct (this) &&
+                  coverage.sanitize (c, this) &&
+                  valueFormat.sanitize_value (c, this, values));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 1 */
   OffsetTo<Coverage>
                 coverage;               /* Offset to Coverage table--from
                                          * beginning of subtable */
   ValueFormat   valueFormat;            /* Defines the types of data in the
                                          * ValueRecord */
   ValueRecord   values;                 /* Defines positioning
@@ skipping 14 matching lines @@
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
     unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint);
-    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
+    if (likely (index == NOT_COVERED)) return_trace (false);
 
-    if (likely (index >= valueCount)) return TRACE_RETURN (false);
+    if (likely (index >= valueCount)) return_trace (false);
 
     valueFormat.apply_value (c->font, c->direction, this,
                              &values[index * valueFormat.get_len ()],
                              buffer->cur_pos());
 
     buffer->idx++;
-    return TRACE_RETURN (true);
+    return_trace (true);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this)
-        && coverage.sanitize (c, this)
-        && valueFormat.sanitize_values (c, this, values, valueCount));
+    return_trace (c->check_struct (this) &&
+                  coverage.sanitize (c, this) &&
+                  valueFormat.sanitize_values (c, this, values, valueCount));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 2 */
   OffsetTo<Coverage>
                 coverage;               /* Offset to Coverage table--from
                                          * beginning of subtable */
   ValueFormat   valueFormat;            /* Defines the types of data in the
                                          * ValueRecord */
   USHORT        valueCount;             /* Number of ValueRecords */
   ValueRecord   values;                 /* Array of ValueRecords--positioning
                                          * values applied to glyphs */
   public:
   DEFINE_SIZE_ARRAY (8, values);
 };
 
 struct SinglePos
 {
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
-    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
     switch (u.format) {
-    case 1: return TRACE_RETURN (c->dispatch (u.format1));
-    case 2: return TRACE_RETURN (c->dispatch (u.format2));
-    default:return TRACE_RETURN (c->default_return_value ());
+    case 1: return_trace (c->dispatch (u.format1));
+    case 2: return_trace (c->dispatch (u.format2));
+    default:return_trace (c->default_return_value ());
     }
   }
 
   protected:
   union {
   USHORT                format;         /* Format identifier */
   SinglePosFormat1      format1;
   SinglePosFormat2      format2;
   } u;
 };
@@ skipping 42 matching lines @@
     hb_buffer_t *buffer = c->buffer;
     unsigned int len1 = valueFormats[0].get_len ();
     unsigned int len2 = valueFormats[1].get_len ();
     unsigned int record_size = USHORT::static_size * (1 + len1 + len2);
 
     const PairValueRecord *record_array = CastP<PairValueRecord> (arrayZ);
     unsigned int count = len;
 
     /* Hand-coded bsearch. */
     if (unlikely (!count))
-      return TRACE_RETURN (false);
+      return_trace (false);
     hb_codepoint_t x = buffer->info[pos].codepoint;
     int min = 0, max = (int) count - 1;
     while (min <= max)
     {
       int mid = (min + max) / 2;
       const PairValueRecord *record = &StructAtOffset<PairValueRecord> (record_array, record_size * mid);
       hb_codepoint_t mid_x = record->secondGlyph;
       if (x < mid_x)
         max = mid - 1;
       else if (x > mid_x)
         min = mid + 1;
       else
       {
         valueFormats[0].apply_value (c->font, c->direction, this,
                                      &record->values[0], buffer->cur_pos());
         valueFormats[1].apply_value (c->font, c->direction, this,
                                      &record->values[len1], buffer->pos[pos]);
         if (len2)
           pos++;
         buffer->idx = pos;
-        return TRACE_RETURN (true);
+        return_trace (true);
       }
     }
 
-    return TRACE_RETURN (false);
+    return_trace (false);
   }
 
   struct sanitize_closure_t {
     const void *base;
     const ValueFormat *valueFormats;
     unsigned int len1; /* valueFormats[0].get_len() */
     unsigned int stride; /* 1 + len1 + len2 */
   };
 
   inline bool sanitize (hb_sanitize_context_t *c, const sanitize_closure_t *closure) const
   {
     TRACE_SANITIZE (this);
     if (!(c->check_struct (this)
-       && c->check_array (arrayZ, USHORT::static_size * closure->stride, len))) return TRACE_RETURN (false);
+       && c->check_array (arrayZ, USHORT::static_size * closure->stride, len))) return_trace (false);
 
     unsigned int count = len;
     const PairValueRecord *record = CastP<PairValueRecord> (arrayZ);
-    return TRACE_RETURN (closure->valueFormats[0].sanitize_values_stride_unsafe (c, closure->base, &record->values[0], count, closure->stride)
-                      && closure->valueFormats[1].sanitize_values_stride_unsafe (c, closure->base, &record->values[closure->len1], count, closure->stride));
+    return_trace (closure->valueFormats[0].sanitize_values_stride_unsafe (c, closure->base, &record->values[0], count, closure->stride) &&
+                  closure->valueFormats[1].sanitize_values_stride_unsafe (c, closure->base, &record->values[closure->len1], count, closure->stride));
   }
 
   protected:
   USHORT        len;                    /* Number of PairValueRecords */
   USHORT        arrayZ[VAR];            /* Array of PairValueRecords--ordered
                                          * by GlyphID of the second glyph */
   public:
   DEFINE_SIZE_ARRAY (2, arrayZ);
 };
 
@@ skipping 11 matching lines @@
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
     unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint);
-    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
+    if (likely (index == NOT_COVERED)) return_trace (false);
 
     hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
     skippy_iter.reset (buffer->idx, 1);
-    if (!skippy_iter.next ()) return TRACE_RETURN (false);
+    if (!skippy_iter.next ()) return_trace (false);
 
-    return TRACE_RETURN ((this+pairSet[index]).apply (c, &valueFormat1, skippy_iter.idx));
+    return_trace ((this+pairSet[index]).apply (c, &valueFormat1, skippy_iter.idx));
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
 
+    if (!c->check_struct (this)) return_trace (false);
+
     unsigned int len1 = valueFormat1.get_len ();
     unsigned int len2 = valueFormat2.get_len ();
     PairSet::sanitize_closure_t closure = {
       this,
       &valueFormat1,
       len1,
       1 + len1 + len2
     };
 
-    return TRACE_RETURN (c->check_struct (this) && coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
+    return_trace (coverage.sanitize (c, this) && pairSet.sanitize (c, this, &closure));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 1 */
   OffsetTo<Coverage>
                 coverage;               /* Offset to Coverage table--from
                                          * beginning of subtable */
   ValueFormat   valueFormat1;           /* Defines the types of data in
                                          * ValueRecord1--for the first glyph
                                          * in the pair--may be zero (0) */
@@ skipping 28 matching lines @@
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
     unsigned int index = (this+coverage).get_coverage  (buffer->cur().codepoint);
-    if (likely (index == NOT_COVERED)) return TRACE_RETURN (false);
+    if (likely (index == NOT_COVERED)) return_trace (false);
 
     hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
     skippy_iter.reset (buffer->idx, 1);
-    if (!skippy_iter.next ()) return TRACE_RETURN (false);
+    if (!skippy_iter.next ()) return_trace (false);
 
     unsigned int len1 = valueFormat1.get_len ();
     unsigned int len2 = valueFormat2.get_len ();
     unsigned int record_len = len1 + len2;
 
     unsigned int klass1 = (this+classDef1).get_class (buffer->cur().codepoint);
     unsigned int klass2 = (this+classDef2).get_class (buffer->info[skippy_iter.idx].codepoint);
-    if (unlikely (klass1 >= class1Count || klass2 >= class2Count)) return TRACE_RETURN (false);
+    if (unlikely (klass1 >= class1Count || klass2 >= class2Count)) return_trace (false);
 
     const Value *v = &values[record_len * (klass1 * class2Count + klass2)];
     valueFormat1.apply_value (c->font, c->direction, this,
                               v, buffer->cur_pos());
     valueFormat2.apply_value (c->font, c->direction, this,
                               v + len1, buffer->pos[skippy_iter.idx]);
 
     buffer->idx = skippy_iter.idx;
     if (len2)
       buffer->idx++;
 
-    return TRACE_RETURN (true);
+    return_trace (true);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
     if (!(c->check_struct (this)
        && coverage.sanitize (c, this)
        && classDef1.sanitize (c, this)
-       && classDef2.sanitize (c, this))) return TRACE_RETURN (false);
+       && classDef2.sanitize (c, this))) return_trace (false);
 
     unsigned int len1 = valueFormat1.get_len ();
     unsigned int len2 = valueFormat2.get_len ();
     unsigned int stride = len1 + len2;
     unsigned int record_size = valueFormat1.get_size () + valueFormat2.get_size ();
     unsigned int count = (unsigned int) class1Count * (unsigned int) class2Count;
-    return TRACE_RETURN (c->check_array (values, record_size, count) &&
-                         valueFormat1.sanitize_values_stride_unsafe (c, this, &values[0], count, stride) &&
-                         valueFormat2.sanitize_values_stride_unsafe (c, this, &values[len1], count, stride));
+    return_trace (c->check_array (values, record_size, count) &&
+                  valueFormat1.sanitize_values_stride_unsafe (c, this, &values[0], count, stride) &&
+                  valueFormat2.sanitize_values_stride_unsafe (c, this, &values[len1], count, stride));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 2 */
   OffsetTo<Coverage>
                 coverage;               /* Offset to Coverage table--from
                                          * beginning of subtable */
   ValueFormat   valueFormat1;           /* ValueRecord definition--for the
                                          * first glyph of the pair--may be zero
                                          * (0) */
@@ skipping 18 matching lines @@
   public:
   DEFINE_SIZE_ARRAY (16, values);
 };
 
 struct PairPos
 {
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
-    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
     switch (u.format) {
-    case 1: return TRACE_RETURN (c->dispatch (u.format1));
-    case 2: return TRACE_RETURN (c->dispatch (u.format2));
-    default:return TRACE_RETURN (c->default_return_value ());
+    case 1: return_trace (c->dispatch (u.format1));
+    case 2: return_trace (c->dispatch (u.format2));
+    default:return_trace (c->default_return_value ());
     }
   }
 
   protected:
   union {
   USHORT                format;         /* Format identifier */
   PairPosFormat1        format1;
   PairPosFormat2        format2;
   } u;
 };
 
 
 struct EntryExitRecord
 {
   friend struct CursivePosFormat1;
 
   inline bool sanitize (hb_sanitize_context_t *c, const void *base) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (entryAnchor.sanitize (c, base) && exitAnchor.sanitize (c, base));
+    return_trace (entryAnchor.sanitize (c, base) && exitAnchor.sanitize (c, base));
   }
 
   protected:
   OffsetTo<Anchor>
                 entryAnchor;            /* Offset to EntryAnchor table--from
                                          * beginning of CursivePos
                                          * subtable--may be NULL */
   OffsetTo<Anchor>
                 exitAnchor;             /* Offset to ExitAnchor table--from
                                          * beginning of CursivePos
                                          * subtable--may be NULL */
   public:
   DEFINE_SIZE_STATIC (4);
 };
 
+static void
+reverse_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction, unsigned int new_parent);
+
 struct CursivePosFormat1
 {
   inline void collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
     (this+coverage).add_coverage (c->input);
   }
 
   inline const Coverage &get_coverage (void) const
   {
     return this+coverage;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
 
     /* We don't handle mark glyphs here. */
-    if (unlikely (_hb_glyph_info_is_mark (&buffer->cur()))) return TRACE_RETURN (false);
+    if (unlikely (_hb_glyph_info_is_mark (&buffer->cur()))) return_trace (false);
 
     const EntryExitRecord &this_record = entryExitRecord[(this+coverage).get_coverage  (buffer->cur().codepoint)];
-    if (!this_record.exitAnchor) return TRACE_RETURN (false);
+    if (!this_record.exitAnchor) return_trace (false);
 
     hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
     skippy_iter.reset (buffer->idx, 1);
-    if (!skippy_iter.next ()) return TRACE_RETURN (false);
+    if (!skippy_iter.next ()) return_trace (false);
 
     const EntryExitRecord &next_record = entryExitRecord[(this+coverage).get_coverage  (buffer->info[skippy_iter.idx].codepoint)];
-    if (!next_record.entryAnchor) return TRACE_RETURN (false);
+    if (!next_record.entryAnchor) return_trace (false);
 
     unsigned int i = buffer->idx;
     unsigned int j = skippy_iter.idx;
 
     hb_position_t entry_x, entry_y, exit_x, exit_y;
     (this+this_record.exitAnchor).get_anchor (c->font, buffer->info[i].codepoint, &exit_x, &exit_y);
     (this+next_record.entryAnchor).get_anchor (c->font, buffer->info[j].codepoint, &entry_x, &entry_y);
 
     hb_glyph_position_t *pos = buffer->pos;
 
@@ skipping 27 matching lines @@
         pos[i].y_offset  -= d;
 
         pos[j].y_advance  =  entry_y;
         break;
       case HB_DIRECTION_INVALID:
       default:
         break;
     }
 
     /* Cross-direction adjustment */
-    if  (c->lookup_props & LookupFlag::RightToLeft) {
-      pos[i].cursive_chain() = j - i;
-      if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
-        pos[i].y_offset = entry_y - exit_y;
-      else
-        pos[i].x_offset = entry_x - exit_x;
-    } else {
-      pos[j].cursive_chain() = i - j;
-      if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
-        pos[j].y_offset = exit_y - entry_y;
-      else
-        pos[j].x_offset = exit_x - entry_x;
+
+    /* We attach child to parent (think graph theory and rooted trees whereas
+     * the root stays on baseline and each node aligns itself against its
+     * parent.
+     *
+     * Optimize things for the case of RightToLeft, as that's most common in
+     * Arabinc. */
+    unsigned int child  = i;
+    unsigned int parent = j;
+    hb_position_t x_offset = entry_x - exit_x;
+    hb_position_t y_offset = entry_y - exit_y;
+    if  (!(c->lookup_props & LookupFlag::RightToLeft))
+    {
+      unsigned int k = child;
+      child = parent;
+      parent = k;
+      x_offset = -x_offset;
+      y_offset = -y_offset;
     }
 
+    /* If child was already connected to someone else, walk through its old
+     * chain and reverse the link direction, such that the whole tree of its
+     * previous connection now attaches to new parent.  Watch out for case
+     * where new parent is on the path from old chain...
+     */
+    reverse_cursive_minor_offset (pos, child, c->direction, parent);
+
+    pos[child].cursive_chain() = parent - child;
+    if (likely (HB_DIRECTION_IS_HORIZONTAL (c->direction)))
+      pos[child].y_offset = y_offset;
+    else
+      pos[child].x_offset = x_offset;
+
     buffer->idx = j;
-    return TRACE_RETURN (true);
+    return_trace (true);
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (coverage.sanitize (c, this) && entryExitRecord.sanitize (c, this));
+    return_trace (coverage.sanitize (c, this) && entryExitRecord.sanitize (c, this));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 1 */
   OffsetTo<Coverage>
                 coverage;               /* Offset to Coverage table--from
                                          * beginning of subtable */
   ArrayOf<EntryExitRecord>
                 entryExitRecord;        /* Array of EntryExit records--in
                                          * Coverage Index order */
   public:
   DEFINE_SIZE_ARRAY (6, entryExitRecord);
 };
 
 struct CursivePos
 {
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
-    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
     switch (u.format) {
-    case 1: return TRACE_RETURN (c->dispatch (u.format1));
-    default:return TRACE_RETURN (c->default_return_value ());
+    case 1: return_trace (c->dispatch (u.format1));
+    default:return_trace (c->default_return_value ());
     }
   }
 
   protected:
   union {
   USHORT                format;         /* Format identifier */
   CursivePosFormat1     format1;
   } u;
 };
 
@@ skipping 15 matching lines @@
   inline const Coverage &get_coverage (void) const
   {
     return this+markCoverage;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
     unsigned int mark_index = (this+markCoverage).get_coverage  (buffer->cur().codepoint);
-    if (likely (mark_index == NOT_COVERED)) return TRACE_RETURN (false);
+    if (likely (mark_index == NOT_COVERED)) return_trace (false);
 
     /* now we search backwards for a non-mark glyph */
     hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
     skippy_iter.reset (buffer->idx, 1);
     skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
     do {
-      if (!skippy_iter.prev ()) return TRACE_RETURN (false);
+      if (!skippy_iter.prev ()) return_trace (false);
       /* We only want to attach to the first of a MultipleSubst sequence.  Reject others. */
       if (0 == _hb_glyph_info_get_lig_comp (&buffer->info[skippy_iter.idx])) break;
       skippy_iter.reject ();
     } while (1);
 
     /* Checking that matched glyph is actually a base glyph by GDEF is too strong; disabled */
-    if (!_hb_glyph_info_is_base_glyph (&buffer->info[skippy_iter.idx])) { /*return TRACE_RETURN (false);*/ }
+    if (!_hb_glyph_info_is_base_glyph (&buffer->info[skippy_iter.idx])) { /*return_trace (false);*/ }
 
     unsigned int base_index = (this+baseCoverage).get_coverage  (buffer->info[skippy_iter.idx].codepoint);
-    if (base_index == NOT_COVERED) return TRACE_RETURN (false);
+    if (base_index == NOT_COVERED) return_trace (false);
 
-    return TRACE_RETURN ((this+markArray).apply (c, mark_index, base_index, this+baseArray, classCount, skippy_iter.idx));
+    return_trace ((this+markArray).apply (c, mark_index, base_index, this+baseArray, classCount, skippy_iter.idx));
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this) && markCoverage.sanitize (c, this) && baseCoverage.sanitize (c, this) &&
-                         markArray.sanitize (c, this) && baseArray.sanitize (c, this, (unsigned int) classCount));
+    return_trace (c->check_struct (this) &&
+                  markCoverage.sanitize (c, this) &&
+                  baseCoverage.sanitize (c, this) &&
+                  markArray.sanitize (c, this) &&
+                  baseArray.sanitize (c, this, (unsigned int) classCount));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 1 */
   OffsetTo<Coverage>
                 markCoverage;           /* Offset to MarkCoverage table--from
                                          * beginning of MarkBasePos subtable */
   OffsetTo<Coverage>
                 baseCoverage;           /* Offset to BaseCoverage table--from
                                          * beginning of MarkBasePos subtable */
   USHORT        classCount;             /* Number of classes defined for marks */
   OffsetTo<MarkArray>
                 markArray;              /* Offset to MarkArray table--from
                                          * beginning of MarkBasePos subtable */
   OffsetTo<BaseArray>
                 baseArray;              /* Offset to BaseArray table--from
                                          * beginning of MarkBasePos subtable */
   public:
   DEFINE_SIZE_STATIC (12);
 };
 
 struct MarkBasePos
 {
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
-    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
     switch (u.format) {
-    case 1: return TRACE_RETURN (c->dispatch (u.format1));
-    default:return TRACE_RETURN (c->default_return_value ());
+    case 1: return_trace (c->dispatch (u.format1));
+    default:return_trace (c->default_return_value ());
     }
   }
 
   protected:
   union {
   USHORT                format;         /* Format identifier */
   MarkBasePosFormat1    format1;
   } u;
 };
 
@@ skipping 20 matching lines @@
   inline const Coverage &get_coverage (void) const
   {
     return this+markCoverage;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
     unsigned int mark_index = (this+markCoverage).get_coverage  (buffer->cur().codepoint);
-    if (likely (mark_index == NOT_COVERED)) return TRACE_RETURN (false);
+    if (likely (mark_index == NOT_COVERED)) return_trace (false);
 
     /* now we search backwards for a non-mark glyph */
     hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
     skippy_iter.reset (buffer->idx, 1);
     skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);
-    if (!skippy_iter.prev ()) return TRACE_RETURN (false);
+    if (!skippy_iter.prev ()) return_trace (false);
 
     /* Checking that matched glyph is actually a ligature by GDEF is too strong; disabled */
-    if (!_hb_glyph_info_is_ligature (&buffer->info[skippy_iter.idx])) { /*return TRACE_RETURN (false);*/ }
+    if (!_hb_glyph_info_is_ligature (&buffer->info[skippy_iter.idx])) { /*return_trace (false);*/ }
 
     unsigned int j = skippy_iter.idx;
     unsigned int lig_index = (this+ligatureCoverage).get_coverage  (buffer->info[j].codepoint);
-    if (lig_index == NOT_COVERED) return TRACE_RETURN (false);
+    if (lig_index == NOT_COVERED) return_trace (false);
 
     const LigatureArray& lig_array = this+ligatureArray;
     const LigatureAttach& lig_attach = lig_array[lig_index];
 
     /* Find component to attach to */
     unsigned int comp_count = lig_attach.rows;
-    if (unlikely (!comp_count)) return TRACE_RETURN (false);
+    if (unlikely (!comp_count)) return_trace (false);
 
     /* We must now check whether the ligature ID of the current mark glyph
      * is identical to the ligature ID of the found ligature.  If yes, we
      * can directly use the component index.  If not, we attach the mark
      * glyph to the last component of the ligature. */
     unsigned int comp_index;
     unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[j]);
     unsigned int mark_id = _hb_glyph_info_get_lig_id (&buffer->cur());
     unsigned int mark_comp = _hb_glyph_info_get_lig_comp (&buffer->cur());
     if (lig_id && lig_id == mark_id && mark_comp > 0)
       comp_index = MIN (comp_count, _hb_glyph_info_get_lig_comp (&buffer->cur())) - 1;
     else
       comp_index = comp_count - 1;
 
-    return TRACE_RETURN ((this+markArray).apply (c, mark_index, comp_index, lig_attach, classCount, j));
+    return_trace ((this+markArray).apply (c, mark_index, comp_index, lig_attach, classCount, j));
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this) && markCoverage.sanitize (c, this) && ligatureCoverage.sanitize (c, this) &&
-                         markArray.sanitize (c, this) && ligatureArray.sanitize (c, this, (unsigned int) classCount));
+    return_trace (c->check_struct (this) &&
+                  markCoverage.sanitize (c, this) &&
+                  ligatureCoverage.sanitize (c, this) &&
+                  markArray.sanitize (c, this) &&
+                  ligatureArray.sanitize (c, this, (unsigned int) classCount));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 1 */
   OffsetTo<Coverage>
                 markCoverage;           /* Offset to Mark Coverage table--from
                                          * beginning of MarkLigPos subtable */
   OffsetTo<Coverage>
                 ligatureCoverage;       /* Offset to Ligature Coverage
                                          * table--from beginning of MarkLigPos
                                          * subtable */
   USHORT        classCount;             /* Number of defined mark classes */
   OffsetTo<MarkArray>
                 markArray;              /* Offset to MarkArray table--from
                                          * beginning of MarkLigPos subtable */
   OffsetTo<LigatureArray>
                 ligatureArray;          /* Offset to LigatureArray table--from
                                          * beginning of MarkLigPos subtable */
   public:
   DEFINE_SIZE_STATIC (12);
 };
 
 struct MarkLigPos
 {
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
-    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
     switch (u.format) {
-    case 1: return TRACE_RETURN (c->dispatch (u.format1));
-    default:return TRACE_RETURN (c->default_return_value ());
+    case 1: return_trace (c->dispatch (u.format1));
+    default:return_trace (c->default_return_value ());
     }
   }
 
   protected:
   union {
   USHORT                format;         /* Format identifier */
   MarkLigPosFormat1     format1;
   } u;
 };
 
@@ skipping 15 matching lines @@
   inline const Coverage &get_coverage (void) const
   {
     return this+mark1Coverage;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
     hb_buffer_t *buffer = c->buffer;
     unsigned int mark1_index = (this+mark1Coverage).get_coverage  (buffer->cur().codepoint);
-    if (likely (mark1_index == NOT_COVERED)) return TRACE_RETURN (false);
+    if (likely (mark1_index == NOT_COVERED)) return_trace (false);
 
     /* now we search backwards for a suitable mark glyph until a non-mark glyph */
     hb_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;
     skippy_iter.reset (buffer->idx, 1);
     skippy_iter.set_lookup_props (c->lookup_props & ~LookupFlag::IgnoreFlags);
-    if (!skippy_iter.prev ()) return TRACE_RETURN (false);
+    if (!skippy_iter.prev ()) return_trace (false);
 
-    if (!_hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx])) { return TRACE_RETURN (false); }
+    if (!_hb_glyph_info_is_mark (&buffer->info[skippy_iter.idx])) { return_trace (false); }
 
     unsigned int j = skippy_iter.idx;
 
     unsigned int id1 = _hb_glyph_info_get_lig_id (&buffer->cur());
     unsigned int id2 = _hb_glyph_info_get_lig_id (&buffer->info[j]);
     unsigned int comp1 = _hb_glyph_info_get_lig_comp (&buffer->cur());
     unsigned int comp2 = _hb_glyph_info_get_lig_comp (&buffer->info[j]);
 
     if (likely (id1 == id2)) {
       if (id1 == 0) /* Marks belonging to the same base. */
         goto good;
       else if (comp1 == comp2) /* Marks belonging to the same ligature component. */
         goto good;
     } else {
       /* If ligature ids don't match, it may be the case that one of the marks
        * itself is a ligature.  In which case match. */
       if ((id1 > 0 && !comp1) || (id2 > 0 && !comp2))
         goto good;
     }
 
     /* Didn't match. */
-    return TRACE_RETURN (false);
+    return_trace (false);
 
     good:
     unsigned int mark2_index = (this+mark2Coverage).get_coverage  (buffer->info[j].codepoint);
-    if (mark2_index == NOT_COVERED) return TRACE_RETURN (false);
+    if (mark2_index == NOT_COVERED) return_trace (false);
 
-    return TRACE_RETURN ((this+mark1Array).apply (c, mark1_index, mark2_index, this+mark2Array, classCount, j));
+    return_trace ((this+mark1Array).apply (c, mark1_index, mark2_index, this+mark2Array, classCount, j));
   }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    return TRACE_RETURN (c->check_struct (this) && mark1Coverage.sanitize (c, this) &&
-                         mark2Coverage.sanitize (c, this) && mark1Array.sanitize (c, this)
-                         && mark2Array.sanitize (c, this, (unsigned int) classCount));
+    return_trace (c->check_struct (this) &&
+                  mark1Coverage.sanitize (c, this) &&
+                  mark2Coverage.sanitize (c, this) &&
+                  mark1Array.sanitize (c, this) &&
+                  mark2Array.sanitize (c, this, (unsigned int) classCount));
   }
 
   protected:
   USHORT        format;                 /* Format identifier--format = 1 */
   OffsetTo<Coverage>
                 mark1Coverage;          /* Offset to Combining Mark1 Coverage
                                          * table--from beginning of MarkMarkPos
                                          * subtable */
   OffsetTo<Coverage>
                 mark2Coverage;          /* Offset to Combining Mark2 Coverage
                                          * table--from beginning of MarkMarkPos
                                          * subtable */
   USHORT        classCount;             /* Number of defined mark classes */
   OffsetTo<MarkArray>
                 mark1Array;             /* Offset to Mark1Array table--from
                                          * beginning of MarkMarkPos subtable */
   OffsetTo<Mark2Array>
                 mark2Array;             /* Offset to Mark2Array table--from
                                          * beginning of MarkMarkPos subtable */
   public:
   DEFINE_SIZE_STATIC (12);
 };
 
 struct MarkMarkPos
 {
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   {
     TRACE_DISPATCH (this, u.format);
-    if (unlikely (!c->may_dispatch (this, &u.format))) TRACE_RETURN (c->default_return_value ());
+    if (unlikely (!c->may_dispatch (this, &u.format))) return_trace (c->no_dispatch_return_value ());
     switch (u.format) {
-    case 1: return TRACE_RETURN (c->dispatch (u.format1));
-    default:return TRACE_RETURN (c->default_return_value ());
+    case 1: return_trace (c->dispatch (u.format1));
+    default:return_trace (c->default_return_value ());
     }
   }
 
   protected:
   union {
   USHORT                format;         /* Format identifier */
   MarkMarkPosFormat1    format1;
   } u;
 };
 
@@ skipping 27 matching lines @@
     MarkMark            = 6,
     Context             = 7,
     ChainContext        = 8,
     Extension           = 9
   };
 
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c, unsigned int lookup_type) const
   {
     TRACE_DISPATCH (this, lookup_type);
-    /* The sub_format passed to may_dispatch is unnecessary but harmless. */
-    if (unlikely (!c->may_dispatch (this, &u.sub_format))) TRACE_RETURN (c->default_return_value ());
+    if (unlikely (!c->may_dispatch (this, &u.sub_format))) return_trace (c->no_dispatch_return_value ());
     switch (lookup_type) {
-    case Single:                return TRACE_RETURN (u.single.dispatch (c));
-    case Pair:                  return TRACE_RETURN (u.pair.dispatch (c));
-    case Cursive:               return TRACE_RETURN (u.cursive.dispatch (c));
-    case MarkBase:              return TRACE_RETURN (u.markBase.dispatch (c));
-    case MarkLig:               return TRACE_RETURN (u.markLig.dispatch (c));
-    case MarkMark:              return TRACE_RETURN (u.markMark.dispatch (c));
-    case Context:               return TRACE_RETURN (u.context.dispatch (c));
-    case ChainContext:          return TRACE_RETURN (u.chainContext.dispatch (c));
-    case Extension:             return TRACE_RETURN (u.extension.dispatch (c));
-    default:                    return TRACE_RETURN (c->default_return_value ());
+    case Single:                return_trace (u.single.dispatch (c));
+    case Pair:                  return_trace (u.pair.dispatch (c));
+    case Cursive:               return_trace (u.cursive.dispatch (c));
+    case MarkBase:              return_trace (u.markBase.dispatch (c));
+    case MarkLig:               return_trace (u.markLig.dispatch (c));
+    case MarkMark:              return_trace (u.markMark.dispatch (c));
+    case Context:               return_trace (u.context.dispatch (c));
+    case ChainContext:          return_trace (u.chainContext.dispatch (c));
+    case Extension:             return_trace (u.extension.dispatch (c));
+    default:                    return_trace (c->default_return_value ());
     }
   }
 
   protected:
   union {
   USHORT                sub_format;
   SinglePos             single;
   PairPos               pair;
   CursivePos            cursive;
   MarkBasePos           markBase;
@@ skipping 14 matching lines @@
   { return Lookup::get_subtable<PosLookupSubTable> (i); }
 
   inline bool is_reverse (void) const
   {
     return false;
   }
 
   inline bool apply (hb_apply_context_t *c) const
   {
     TRACE_APPLY (this);
-    return TRACE_RETURN (dispatch (c));
+    return_trace (dispatch (c));
   }
 
   inline hb_collect_glyphs_context_t::return_t collect_glyphs (hb_collect_glyphs_context_t *c) const
   {
     TRACE_COLLECT_GLYPHS (this);
-    return TRACE_RETURN (dispatch (c));
+    return_trace (dispatch (c));
   }
 
   template <typename set_t>
   inline void add_coverage (set_t *glyphs) const
   {
     hb_add_coverage_context_t<set_t> c (glyphs);
     dispatch (&c);
   }
 
   static bool apply_recurse_func (hb_apply_context_t *c, unsigned int lookup_index);
 
   template <typename context_t>
   static inline typename context_t::return_t dispatch_recurse_func (context_t *c, unsigned int lookup_index);
 
   template <typename context_t>
   inline typename context_t::return_t dispatch (context_t *c) const
   { return Lookup::dispatch<PosLookupSubTable> (c); }
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    if (unlikely (!Lookup::sanitize (c))) return TRACE_RETURN (false);
-    return TRACE_RETURN (dispatch (c));
+    if (unlikely (!Lookup::sanitize (c))) return_trace (false);
+    return_trace (dispatch (c));
   }
 };
 
 typedef OffsetListOf<PosLookup> PosLookupList;
 
 /*
  * GPOS -- The Glyph Positioning Table
  */
 
 struct GPOS : GSUBGPOS
 {
   static const hb_tag_t tableTag        = HB_OT_TAG_GPOS;
 
   inline const PosLookup& get_lookup (unsigned int i) const
   { return CastR<PosLookup> (GSUBGPOS::get_lookup (i)); }
 
   static inline void position_start (hb_font_t *font, hb_buffer_t *buffer);
   static inline void position_finish (hb_font_t *font, hb_buffer_t *buffer);
 
   inline bool sanitize (hb_sanitize_context_t *c) const
   {
     TRACE_SANITIZE (this);
-    if (unlikely (!GSUBGPOS::sanitize (c))) return TRACE_RETURN (false);
+    if (unlikely (!GSUBGPOS::sanitize (c))) return_trace (false);
     const OffsetTo<PosLookupList> &list = CastR<OffsetTo<PosLookupList> > (lookupList);
-    return TRACE_RETURN (list.sanitize (c, this));
+    return_trace (list.sanitize (c, this));
   }
   public:
   DEFINE_SIZE_STATIC (10);
 };
 
 
 static void
+reverse_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction, unsigned int new_parent)
+{
+  unsigned int j = pos[i].cursive_chain();
+  if (likely (!j))
+    return;
+
+  j += i;
+
+  pos[i].cursive_chain() = 0;
+
+  /* Stop if we see new parent in the chain. */
+  if (j == new_parent)
+    return;
+
+  reverse_cursive_minor_offset (pos, j, direction, new_parent);
+
+  if (HB_DIRECTION_IS_HORIZONTAL (direction))
+    pos[j].y_offset = -pos[i].y_offset;
+  else
+    pos[j].x_offset = -pos[i].x_offset;
+
+  pos[j].cursive_chain() = i - j;
+}
+static void
 fix_cursive_minor_offset (hb_glyph_position_t *pos, unsigned int i, hb_direction_t direction)
 {
   unsigned int j = pos[i].cursive_chain();
   if (likely (!j))
     return;
 
   j += i;
 
   pos[i].cursive_chain() = 0;
 
@@ skipping 83 matching lines @@
 
 
 #undef attach_lookback
 #undef cursive_chain
 
 
 } /* namespace OT */
 
 
 #endif /* HB_OT_LAYOUT_GPOS_TABLE_HH */