| Index: third_party/ots/src/gpos.cc
 | 
| diff --git a/third_party/ots/src/gpos.cc b/third_party/ots/src/gpos.cc
 | 
| new file mode 100644
 | 
| index 0000000000000000000000000000000000000000..a2b968726e2793b52e1574fffbbf999819e1c286
 | 
| --- /dev/null
 | 
| +++ b/third_party/ots/src/gpos.cc
 | 
| @@ -0,0 +1,828 @@
 | 
| +// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 | 
| +// Use of this source code is governed by a BSD-style license that can be
 | 
| +// found in the LICENSE file.
 | 
| +
 | 
| +#include "gpos.h"
 | 
| +
 | 
| +#include <limits>
 | 
| +#include <vector>
 | 
| +
 | 
| +#include "layout.h"
 | 
| +#include "maxp.h"
 | 
| +
 | 
| +// GPOS - The Glyph Positioning Table
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| +// http://www.microsoft.com/typography/otspec/gpos.htm
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| +
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| +#define TABLE_NAME "GPOS"
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| +
 | 
| +namespace {
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| +
 | 
| +enum GPOS_TYPE {
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| +  GPOS_TYPE_SINGLE_ADJUSTMENT = 1,
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| +  GPOS_TYPE_PAIR_ADJUSTMENT = 2,
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| +  GPOS_TYPE_CURSIVE_ATTACHMENT = 3,
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| +  GPOS_TYPE_MARK_TO_BASE_ATTACHMENT = 4,
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| +  GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT = 5,
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| +  GPOS_TYPE_MARK_TO_MARK_ATTACHMENT = 6,
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| +  GPOS_TYPE_CONTEXT_POSITIONING = 7,
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| +  GPOS_TYPE_CHAINED_CONTEXT_POSITIONING = 8,
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| +  GPOS_TYPE_EXTENSION_POSITIONING = 9,
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| +  GPOS_TYPE_RESERVED = 10
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| +};
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| +
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| +// The size of gpos header.
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| +const unsigned kGposHeaderSize = 10;
 | 
| +// The maximum format number for anchor tables.
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| +const uint16_t kMaxAnchorFormat = 3;
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| +// The maximum number of class value.
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| +const uint16_t kMaxClassDefValue = 0xFFFF;
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| +
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| +// Lookup type parsers.
 | 
| +bool ParseSingleAdjustment(const ots::OpenTypeFile *file,
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| +                           const uint8_t *data, const size_t length);
 | 
| +bool ParsePairAdjustment(const ots::OpenTypeFile *file,
 | 
| +                         const uint8_t *data, const size_t length);
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| +bool ParseCursiveAttachment(const ots::OpenTypeFile *file,
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| +                            const uint8_t *data, const size_t length);
 | 
| +bool ParseMarkToBaseAttachment(const ots::OpenTypeFile *file,
 | 
| +                               const uint8_t *data, const size_t length);
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| +bool ParseMarkToLigatureAttachment(const ots::OpenTypeFile *file,
 | 
| +                                   const uint8_t *data, const size_t length);
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| +bool ParseMarkToMarkAttachment(const ots::OpenTypeFile *file,
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| +                               const uint8_t *data, const size_t length);
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| +bool ParseContextPositioning(const ots::OpenTypeFile *file,
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| +                             const uint8_t *data, const size_t length);
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| +bool ParseChainedContextPositioning(const ots::OpenTypeFile *file,
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| +                                    const uint8_t *data, const size_t length);
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| +bool ParseExtensionPositioning(const ots::OpenTypeFile *file,
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| +                               const uint8_t *data, const size_t length);
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| +
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| +const ots::LookupSubtableParser::TypeParser kGposTypeParsers[] = {
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| +  {GPOS_TYPE_SINGLE_ADJUSTMENT, ParseSingleAdjustment},
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| +  {GPOS_TYPE_PAIR_ADJUSTMENT, ParsePairAdjustment},
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| +  {GPOS_TYPE_CURSIVE_ATTACHMENT, ParseCursiveAttachment},
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| +  {GPOS_TYPE_MARK_TO_BASE_ATTACHMENT, ParseMarkToBaseAttachment},
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| +  {GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT, ParseMarkToLigatureAttachment},
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| +  {GPOS_TYPE_MARK_TO_MARK_ATTACHMENT, ParseMarkToMarkAttachment},
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| +  {GPOS_TYPE_CONTEXT_POSITIONING, ParseContextPositioning},
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| +  {GPOS_TYPE_CHAINED_CONTEXT_POSITIONING, ParseChainedContextPositioning},
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| +  {GPOS_TYPE_EXTENSION_POSITIONING, ParseExtensionPositioning}
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| +};
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| +
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| +const ots::LookupSubtableParser kGposLookupSubtableParser = {
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| +  arraysize(kGposTypeParsers),
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| +  GPOS_TYPE_EXTENSION_POSITIONING, kGposTypeParsers
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| +};
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| +
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| +// Shared Tables: ValueRecord, Anchor Table, and MarkArray
 | 
| +
 | 
| +bool ParseValueRecord(const ots::OpenTypeFile *file,
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| +                      ots::Buffer* subtable, const uint8_t *data,
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| +                      const size_t length, const uint16_t value_format) {
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| +  // Check existence of adjustment fields.
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| +  for (unsigned i = 0; i < 4; ++i) {
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| +    if ((value_format >> i) & 0x1) {
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| +      // Just read the field since these fileds could take an arbitrary values.
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| +      if (!subtable->Skip(2)) {
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| +        return OTS_FAILURE_MSG("Failed to read value reacord component");
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| +      }
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| +    }
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| +  }
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| +
 | 
| +  // Check existence of offsets to device table.
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| +  for (unsigned i = 0; i < 4; ++i) {
 | 
| +    if ((value_format >> (i + 4)) & 0x1) {
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| +      uint16_t offset = 0;
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| +      if (!subtable->ReadU16(&offset)) {
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| +        return OTS_FAILURE_MSG("Failed to read value record offset");
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| +      }
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| +      if (offset) {
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| +        // TODO(bashi): Is it possible that device tables locate before
 | 
| +        // this record? No fonts contain such offset AKAIF.
 | 
| +        if (offset >= length) {
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| +          return OTS_FAILURE_MSG("Value record offset too high %d >= %ld", offset, length);
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| +        }
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| +        if (!ots::ParseDeviceTable(file, data + offset, length - offset)) {
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| +          return OTS_FAILURE_MSG("Failed to parse device table in value record");
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| +        }
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| +      }
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| +    }
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| +  }
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| +  return true;
 | 
| +}
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| +
 | 
| +bool ParseAnchorTable(const ots::OpenTypeFile *file,
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| +                      const uint8_t *data, const size_t length) {
 | 
| +  ots::Buffer subtable(data, length);
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| +
 | 
| +  uint16_t format = 0;
 | 
| +  // Read format and skip 2 2-byte fields that could be arbitrary values.
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| +  if (!subtable.ReadU16(&format) ||
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| +      !subtable.Skip(4)) {
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| +    return OTS_FAILURE_MSG("Faled to read anchor table");
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| +  }
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| +
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| +  if (format == 0 || format > kMaxAnchorFormat) {
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| +    return OTS_FAILURE_MSG("Bad Anchor table format %d", format);
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| +  }
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| +
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| +  // Format 2 and 3 has additional fields.
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| +  if (format == 2) {
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| +    // Format 2 provides an index to a glyph contour point, which will take
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| +    // arbitrary value.
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| +    uint16_t anchor_point = 0;
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| +    if (!subtable.ReadU16(&anchor_point)) {
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| +      return OTS_FAILURE_MSG("Failed to read anchor point in format 2 Anchor Table");
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| +    }
 | 
| +  } else if (format == 3) {
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| +    uint16_t offset_x_device = 0;
 | 
| +    uint16_t offset_y_device = 0;
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| +    if (!subtable.ReadU16(&offset_x_device) ||
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| +        !subtable.ReadU16(&offset_y_device)) {
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| +      return OTS_FAILURE_MSG("Failed to read device table offsets in format 3 anchor table");
 | 
| +    }
 | 
| +    const unsigned format_end = static_cast<unsigned>(10);
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| +    if (offset_x_device) {
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| +      if (offset_x_device < format_end || offset_x_device >= length) {
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| +        return OTS_FAILURE_MSG("Bad x device table offset %d", offset_x_device);
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| +      }
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| +      if (!ots::ParseDeviceTable(file, data + offset_x_device,
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| +                                 length - offset_x_device)) {
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| +        return OTS_FAILURE_MSG("Failed to parse device table in anchor table");
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| +      }
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| +    }
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| +    if (offset_y_device) {
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| +      if (offset_y_device < format_end || offset_y_device >= length) {
 | 
| +        return OTS_FAILURE_MSG("Bad y device table offset %d", offset_y_device);
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| +      }
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| +      if (!ots::ParseDeviceTable(file, data + offset_y_device,
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| +                                 length - offset_y_device)) {
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| +        return OTS_FAILURE_MSG("Failed to parse device table in anchor table");
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| +      }
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| +    }
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| +  }
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| +  return true;
 | 
| +}
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| +
 | 
| +bool ParseMarkArrayTable(const ots::OpenTypeFile *file,
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| +                         const uint8_t *data, const size_t length,
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| +                         const uint16_t class_count) {
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| +  ots::Buffer subtable(data, length);
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| +
 | 
| +  uint16_t mark_count = 0;
 | 
| +  if (!subtable.ReadU16(&mark_count)) {
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| +    return OTS_FAILURE_MSG("Can't read mark table length");
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| +  }
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| +
 | 
| +  // MarkRecord consists of 4-bytes.
 | 
| +  const unsigned mark_records_end = 4 * static_cast<unsigned>(mark_count) + 2;
 | 
| +  if (mark_records_end > std::numeric_limits<uint16_t>::max()) {
 | 
| +    return OTS_FAILURE_MSG("Bad mark table length");
 | 
| +  }
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| +  for (unsigned i = 0; i < mark_count; ++i) {
 | 
| +    uint16_t class_value = 0;
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| +    uint16_t offset_mark_anchor = 0;
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| +    if (!subtable.ReadU16(&class_value) ||
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| +        !subtable.ReadU16(&offset_mark_anchor)) {
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| +      return OTS_FAILURE_MSG("Can't read mark table %d", i);
 | 
| +    }
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| +    // |class_value| may take arbitrary values including 0 here so we don't
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| +    // check the value.
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| +    if (offset_mark_anchor < mark_records_end ||
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| +        offset_mark_anchor >= length) {
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| +      return OTS_FAILURE_MSG("Bad mark anchor offset %d for mark table %d", offset_mark_anchor, i);
 | 
| +    }
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| +    if (!ParseAnchorTable(file, data + offset_mark_anchor,
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| +                          length - offset_mark_anchor)) {
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| +      return OTS_FAILURE_MSG("Faled to parse anchor table for mark table %d", i);
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| +    }
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| +  }
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| +
 | 
| +  return true;
 | 
| +}
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| +
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| +// Lookup Type 1:
 | 
| +// Single Adjustment Positioning Subtable
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| +bool ParseSingleAdjustment(const ots::OpenTypeFile *file, const uint8_t *data,
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| +                           const size_t length) {
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| +  ots::Buffer subtable(data, length);
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| +
 | 
| +  uint16_t format = 0;
 | 
| +  uint16_t offset_coverage = 0;
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| +  uint16_t value_format = 0;
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| +  if (!subtable.ReadU16(&format) ||
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| +      !subtable.ReadU16(&offset_coverage) ||
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| +      !subtable.ReadU16(&value_format)) {
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| +    return OTS_FAILURE_MSG("Can't read single adjustment information");
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| +  }
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| +
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| +  if (format == 1) {
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| +    // Format 1 exactly one value record.
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| +    if (!ParseValueRecord(file, &subtable, data, length, value_format)) {
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| +      return OTS_FAILURE_MSG("Failed to parse format 1 single adjustment table");
 | 
| +    }
 | 
| +  } else if (format == 2) {
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| +    uint16_t value_count = 0;
 | 
| +    if (!subtable.ReadU16(&value_count)) {
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| +      return OTS_FAILURE_MSG("Failed to parse format 2 single adjustment table");
 | 
| +    }
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| +    for (unsigned i = 0; i < value_count; ++i) {
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| +      if (!ParseValueRecord(file, &subtable, data, length, value_format)) {
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| +        return OTS_FAILURE_MSG("Failed to parse value record %d in format 2 single adjustment table", i);
 | 
| +      }
 | 
| +    }
 | 
| +  } else {
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| +    return OTS_FAILURE_MSG("Bad format %d in single adjustment table", format);
 | 
| +  }
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| +
 | 
| +  if (offset_coverage < subtable.offset() || offset_coverage >= length) {
 | 
| +    return OTS_FAILURE_MSG("Bad coverage offset %d in single adjustment table", offset_coverage);
 | 
| +  }
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| +
 | 
| +  if (!ots::ParseCoverageTable(file, data + offset_coverage,
 | 
| +                               length - offset_coverage,
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| +                               file->maxp->num_glyphs)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to parse coverage table in single adjustment table");
 | 
| +  }
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| +
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +bool ParsePairSetTable(const ots::OpenTypeFile *file,
 | 
| +                       const uint8_t *data, const size_t length,
 | 
| +                       const uint16_t value_format1,
 | 
| +                       const uint16_t value_format2,
 | 
| +                       const uint16_t num_glyphs) {
 | 
| +  ots::Buffer subtable(data, length);
 | 
| +
 | 
| +  uint16_t value_count = 0;
 | 
| +  if (!subtable.ReadU16(&value_count)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read pair set table structure");
 | 
| +  }
 | 
| +  for (unsigned i = 0; i < value_count; ++i) {
 | 
| +    // Check pair value record.
 | 
| +    uint16_t glyph_id = 0;
 | 
| +    if (!subtable.ReadU16(&glyph_id)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to read glyph in pair value record %d", i);
 | 
| +    }
 | 
| +    if (glyph_id >= num_glyphs) {
 | 
| +      return OTS_FAILURE_MSG("glyph id %d too high >= %d", glyph_id, num_glyphs);
 | 
| +    }
 | 
| +    if (!ParseValueRecord(file, &subtable, data, length, value_format1)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to parse value record in format 1 pair set table");
 | 
| +    }
 | 
| +    if (!ParseValueRecord(file, &subtable, data, length, value_format2)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to parse value record in format 2 pair set table");
 | 
| +    }
 | 
| +  }
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +bool ParsePairPosFormat1(const ots::OpenTypeFile *file,
 | 
| +                         const uint8_t *data, const size_t length,
 | 
| +                         const uint16_t value_format1,
 | 
| +                         const uint16_t value_format2,
 | 
| +                         const uint16_t num_glyphs) {
 | 
| +  ots::Buffer subtable(data, length);
 | 
| +
 | 
| +  // Skip 8 bytes that are already read before.
 | 
| +  if (!subtable.Skip(8)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read pair pos table structure");
 | 
| +  }
 | 
| +
 | 
| +  uint16_t pair_set_count = 0;
 | 
| +  if (!subtable.ReadU16(&pair_set_count)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read pair pos set count");
 | 
| +  }
 | 
| +
 | 
| +  const unsigned pair_pos_end = 2 * static_cast<unsigned>(pair_set_count) + 10;
 | 
| +  if (pair_pos_end > std::numeric_limits<uint16_t>::max()) {
 | 
| +    return OTS_FAILURE_MSG("Bad pair set length %d", pair_pos_end);
 | 
| +  }
 | 
| +  for (unsigned i = 0; i < pair_set_count; ++i) {
 | 
| +    uint16_t pair_set_offset = 0;
 | 
| +    if (!subtable.ReadU16(&pair_set_offset)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to read pair set offset for pair set %d", i);
 | 
| +    }
 | 
| +    if (pair_set_offset < pair_pos_end || pair_set_offset >= length) {
 | 
| +      return OTS_FAILURE_MSG("Bad pair set offset %d for pair set %d", pair_set_offset, i);
 | 
| +    }
 | 
| +    // Check pair set tables
 | 
| +    if (!ParsePairSetTable(file, data + pair_set_offset, length - pair_set_offset,
 | 
| +                           value_format1, value_format2,
 | 
| +                           num_glyphs)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to parse pair set table %d", i);
 | 
| +    }
 | 
| +  }
 | 
| +
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +bool ParsePairPosFormat2(const ots::OpenTypeFile *file,
 | 
| +                         const uint8_t *data, const size_t length,
 | 
| +                         const uint16_t value_format1,
 | 
| +                         const uint16_t value_format2,
 | 
| +                         const uint16_t num_glyphs) {
 | 
| +  ots::Buffer subtable(data, length);
 | 
| +
 | 
| +  // Skip 8 bytes that are already read before.
 | 
| +  if (!subtable.Skip(8)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read pair pos format 2 structure");
 | 
| +  }
 | 
| +
 | 
| +  uint16_t offset_class_def1 = 0;
 | 
| +  uint16_t offset_class_def2 = 0;
 | 
| +  uint16_t class1_count = 0;
 | 
| +  uint16_t class2_count = 0;
 | 
| +  if (!subtable.ReadU16(&offset_class_def1) ||
 | 
| +      !subtable.ReadU16(&offset_class_def2) ||
 | 
| +      !subtable.ReadU16(&class1_count) ||
 | 
| +      !subtable.ReadU16(&class2_count)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read pair pos format 2 data");
 | 
| +  }
 | 
| +
 | 
| +  // Check class 1 records.
 | 
| +  for (unsigned i = 0; i < class1_count; ++i) {
 | 
| +    // Check class 2 records.
 | 
| +    for (unsigned j = 0; j < class2_count; ++j) {
 | 
| +      if (value_format1 && !ParseValueRecord(file, &subtable, data, length,
 | 
| +                                             value_format1)) {
 | 
| +        return OTS_FAILURE_MSG("Failed to parse value record 1 %d and %d", j, i);
 | 
| +      }
 | 
| +      if (value_format2 && !ParseValueRecord(file, &subtable, data, length,
 | 
| +                                             value_format2)) {
 | 
| +        return OTS_FAILURE_MSG("Falied to parse value record 2 %d and %d", j, i);
 | 
| +      }
 | 
| +    }
 | 
| +  }
 | 
| +
 | 
| +  // Check class definition tables.
 | 
| +  if (offset_class_def1 < subtable.offset() || offset_class_def1 >= length ||
 | 
| +      offset_class_def2 < subtable.offset() || offset_class_def2 >= length) {
 | 
| +    return OTS_FAILURE_MSG("Bad class definition table offsets %d or %d", offset_class_def1, offset_class_def2);
 | 
| +  }
 | 
| +  if (!ots::ParseClassDefTable(file, data + offset_class_def1,
 | 
| +                               length - offset_class_def1,
 | 
| +                               num_glyphs, kMaxClassDefValue)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to parse class definition table 1");
 | 
| +  }
 | 
| +  if (!ots::ParseClassDefTable(file, data + offset_class_def2,
 | 
| +                               length - offset_class_def2,
 | 
| +                               num_glyphs, kMaxClassDefValue)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to parse class definition table 2");
 | 
| +  }
 | 
| +
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +// Lookup Type 2:
 | 
| +// Pair Adjustment Positioning Subtable
 | 
| +bool ParsePairAdjustment(const ots::OpenTypeFile *file, const uint8_t *data,
 | 
| +                         const size_t length) {
 | 
| +  ots::Buffer subtable(data, length);
 | 
| +
 | 
| +  uint16_t format = 0;
 | 
| +  uint16_t offset_coverage = 0;
 | 
| +  uint16_t value_format1 = 0;
 | 
| +  uint16_t value_format2 = 0;
 | 
| +  if (!subtable.ReadU16(&format) ||
 | 
| +      !subtable.ReadU16(&offset_coverage) ||
 | 
| +      !subtable.ReadU16(&value_format1) ||
 | 
| +      !subtable.ReadU16(&value_format2)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read pair adjustment structure");
 | 
| +  }
 | 
| +
 | 
| +  if (format == 1) {
 | 
| +    if (!ParsePairPosFormat1(file, data, length, value_format1, value_format2,
 | 
| +                             file->maxp->num_glyphs)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to parse pair pos format 1");
 | 
| +    }
 | 
| +  } else if (format == 2) {
 | 
| +    if (!ParsePairPosFormat2(file, data, length, value_format1, value_format2,
 | 
| +                             file->maxp->num_glyphs)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to parse pair format 2");
 | 
| +    }
 | 
| +  } else {
 | 
| +    return OTS_FAILURE_MSG("Bad pos pair format %d", format);
 | 
| +  }
 | 
| +
 | 
| +  if (offset_coverage < subtable.offset() || offset_coverage >= length) {
 | 
| +    return OTS_FAILURE_MSG("Bad pair pos offset coverage %d", offset_coverage);
 | 
| +  }
 | 
| +  if (!ots::ParseCoverageTable(file, data + offset_coverage,
 | 
| +                               length - offset_coverage,
 | 
| +                               file->maxp->num_glyphs)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to parse coverage table");
 | 
| +  }
 | 
| +
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +// Lookup Type 3
 | 
| +// Cursive Attachment Positioning Subtable
 | 
| +bool ParseCursiveAttachment(const ots::OpenTypeFile *file, const uint8_t *data,
 | 
| +                            const size_t length) {
 | 
| +  ots::Buffer subtable(data, length);
 | 
| +
 | 
| +  uint16_t format = 0;
 | 
| +  uint16_t offset_coverage = 0;
 | 
| +  uint16_t entry_exit_count = 0;
 | 
| +  if (!subtable.ReadU16(&format) ||
 | 
| +      !subtable.ReadU16(&offset_coverage) ||
 | 
| +      !subtable.ReadU16(&entry_exit_count)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read cursive attachment structure");
 | 
| +  }
 | 
| +
 | 
| +  if (format != 1) {
 | 
| +    return OTS_FAILURE_MSG("Bad cursive attachment format %d", format);
 | 
| +  }
 | 
| +
 | 
| +  // Check entry exit records.
 | 
| +  const unsigned entry_exit_records_end =
 | 
| +      2 * static_cast<unsigned>(entry_exit_count) + 6;
 | 
| +  if (entry_exit_records_end > std::numeric_limits<uint16_t>::max()) {
 | 
| +    return OTS_FAILURE_MSG("Bad entry exit record end %d", entry_exit_records_end);
 | 
| +  }
 | 
| +  for (unsigned i = 0; i < entry_exit_count; ++i) {
 | 
| +    uint16_t offset_entry_anchor = 0;
 | 
| +    uint16_t offset_exit_anchor = 0;
 | 
| +    if (!subtable.ReadU16(&offset_entry_anchor) ||
 | 
| +        !subtable.ReadU16(&offset_exit_anchor)) {
 | 
| +      return OTS_FAILURE_MSG("Can't read entry exit record %d", i);
 | 
| +    }
 | 
| +    // These offsets could be NULL.
 | 
| +    if (offset_entry_anchor) {
 | 
| +      if (offset_entry_anchor < entry_exit_records_end ||
 | 
| +          offset_entry_anchor >= length) {
 | 
| +        return OTS_FAILURE_MSG("Bad entry anchor offset %d in entry exit record %d", offset_entry_anchor, i);
 | 
| +      }
 | 
| +      if (!ParseAnchorTable(file, data + offset_entry_anchor,
 | 
| +                            length - offset_entry_anchor)) {
 | 
| +        return OTS_FAILURE_MSG("Failed to parse entry anchor table in entry exit record %d", i);
 | 
| +      }
 | 
| +    }
 | 
| +    if (offset_exit_anchor) {
 | 
| +      if (offset_exit_anchor < entry_exit_records_end ||
 | 
| +         offset_exit_anchor >= length) {
 | 
| +        return OTS_FAILURE_MSG("Bad exit anchor offset %d in entry exit record %d", offset_exit_anchor, i);
 | 
| +      }
 | 
| +      if (!ParseAnchorTable(file, data + offset_exit_anchor,
 | 
| +                            length - offset_exit_anchor)) {
 | 
| +        return OTS_FAILURE_MSG("Failed to parse exit anchor table in entry exit record %d", i);
 | 
| +      }
 | 
| +    }
 | 
| +  }
 | 
| +
 | 
| +  if (offset_coverage < subtable.offset() || offset_coverage >= length) {
 | 
| +    return OTS_FAILURE_MSG("Bad coverage offset in cursive attachment %d", offset_coverage);
 | 
| +  }
 | 
| +  if (!ots::ParseCoverageTable(file, data + offset_coverage,
 | 
| +                               length - offset_coverage,
 | 
| +                               file->maxp->num_glyphs)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to parse coverage table in cursive attachment");
 | 
| +  }
 | 
| +
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +bool ParseAnchorArrayTable(const ots::OpenTypeFile *file,
 | 
| +                           const uint8_t *data, const size_t length,
 | 
| +                           const uint16_t class_count) {
 | 
| +  ots::Buffer subtable(data, length);
 | 
| +
 | 
| +  uint16_t record_count = 0;
 | 
| +  if (!subtable.ReadU16(&record_count)) {
 | 
| +    return OTS_FAILURE_MSG("Can't read anchor array length");
 | 
| +  }
 | 
| +
 | 
| +  const unsigned anchor_array_end = 2 * static_cast<unsigned>(record_count) *
 | 
| +      static_cast<unsigned>(class_count) + 2;
 | 
| +  if (anchor_array_end > std::numeric_limits<uint16_t>::max()) {
 | 
| +    return OTS_FAILURE_MSG("Bad end of anchor array %d", anchor_array_end);
 | 
| +  }
 | 
| +  for (unsigned i = 0; i < record_count; ++i) {
 | 
| +    for (unsigned j = 0; j < class_count; ++j) {
 | 
| +      uint16_t offset_record = 0;
 | 
| +      if (!subtable.ReadU16(&offset_record)) {
 | 
| +        return OTS_FAILURE_MSG("Can't read anchor array record offset for class %d and record %d", j, i);
 | 
| +      }
 | 
| +      // |offset_record| could be NULL.
 | 
| +      if (offset_record) {
 | 
| +        if (offset_record < anchor_array_end || offset_record >= length) {
 | 
| +          return OTS_FAILURE_MSG("Bad record offset %d in class %d, record %d", offset_record, j, i);
 | 
| +        }
 | 
| +        if (!ParseAnchorTable(file, data + offset_record,
 | 
| +                              length - offset_record)) {
 | 
| +          return OTS_FAILURE_MSG("Failed to parse anchor table for class %d, record %d", j, i);
 | 
| +        }
 | 
| +      }
 | 
| +    }
 | 
| +  }
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +bool ParseLigatureArrayTable(const ots::OpenTypeFile *file,
 | 
| +                             const uint8_t *data, const size_t length,
 | 
| +                             const uint16_t class_count) {
 | 
| +  ots::Buffer subtable(data, length);
 | 
| +
 | 
| +  uint16_t ligature_count = 0;
 | 
| +  if (!subtable.ReadU16(&ligature_count)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read ligature count");
 | 
| +  }
 | 
| +  for (unsigned i = 0; i < ligature_count; ++i) {
 | 
| +    uint16_t offset_ligature_attach = 0;
 | 
| +    if (!subtable.ReadU16(&offset_ligature_attach)) {
 | 
| +      return OTS_FAILURE_MSG("Can't read ligature offset %d", i);
 | 
| +    }
 | 
| +    if (offset_ligature_attach < 2 || offset_ligature_attach >= length) {
 | 
| +      return OTS_FAILURE_MSG("Bad ligature attachment offset %d in ligature %d", offset_ligature_attach, i);
 | 
| +    }
 | 
| +    if (!ParseAnchorArrayTable(file, data + offset_ligature_attach,
 | 
| +                               length - offset_ligature_attach, class_count)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to parse anchor table for ligature %d", i);
 | 
| +    }
 | 
| +  }
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +// Common parser for Lookup Type 4, 5 and 6.
 | 
| +bool ParseMarkToAttachmentSubtables(const ots::OpenTypeFile *file,
 | 
| +                                    const uint8_t *data, const size_t length,
 | 
| +                                    const GPOS_TYPE type) {
 | 
| +  ots::Buffer subtable(data, length);
 | 
| +
 | 
| +  uint16_t format = 0;
 | 
| +  uint16_t offset_coverage1 = 0;
 | 
| +  uint16_t offset_coverage2 = 0;
 | 
| +  uint16_t class_count = 0;
 | 
| +  uint16_t offset_mark_array = 0;
 | 
| +  uint16_t offset_type_specific_array = 0;
 | 
| +  if (!subtable.ReadU16(&format) ||
 | 
| +      !subtable.ReadU16(&offset_coverage1) ||
 | 
| +      !subtable.ReadU16(&offset_coverage2) ||
 | 
| +      !subtable.ReadU16(&class_count) ||
 | 
| +      !subtable.ReadU16(&offset_mark_array) ||
 | 
| +      !subtable.ReadU16(&offset_type_specific_array)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to read mark attachment subtable header");
 | 
| +  }
 | 
| +
 | 
| +  if (format != 1) {
 | 
| +    return OTS_FAILURE_MSG("bad mark attachment subtable format %d", format);
 | 
| +  }
 | 
| +
 | 
| +  const unsigned header_end = static_cast<unsigned>(subtable.offset());
 | 
| +  if (header_end > std::numeric_limits<uint16_t>::max()) {
 | 
| +    return OTS_FAILURE_MSG("Bad mark attachment subtable size ending at %d", header_end);
 | 
| +  }
 | 
| +  if (offset_coverage1 < header_end || offset_coverage1 >= length) {
 | 
| +    return OTS_FAILURE_MSG("Bad coverage 1 offset %d", offset_coverage1);
 | 
| +  }
 | 
| +  if (!ots::ParseCoverageTable(file, data + offset_coverage1,
 | 
| +                               length - offset_coverage1,
 | 
| +                               file->maxp->num_glyphs)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to parse converge 1 table");
 | 
| +  }
 | 
| +  if (offset_coverage2 < header_end || offset_coverage2 >= length) {
 | 
| +    return OTS_FAILURE_MSG("Bad coverage 2 offset %d", offset_coverage2);
 | 
| +  }
 | 
| +  if (!ots::ParseCoverageTable(file, data + offset_coverage2,
 | 
| +                               length - offset_coverage2,
 | 
| +                               file->maxp->num_glyphs)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to parse coverage table 2");
 | 
| +  }
 | 
| +
 | 
| +  if (offset_mark_array < header_end || offset_mark_array >= length) {
 | 
| +    return OTS_FAILURE_MSG("Bad mark array offset %d", offset_mark_array);
 | 
| +  }
 | 
| +  if (!ParseMarkArrayTable(file, data + offset_mark_array,
 | 
| +                           length - offset_mark_array, class_count)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to parse mark array");
 | 
| +  }
 | 
| +
 | 
| +  if (offset_type_specific_array < header_end ||
 | 
| +      offset_type_specific_array >= length) {
 | 
| +    return OTS_FAILURE_MSG("Bad type specific array offset %d", offset_type_specific_array);
 | 
| +  }
 | 
| +  if (type == GPOS_TYPE_MARK_TO_BASE_ATTACHMENT ||
 | 
| +      type == GPOS_TYPE_MARK_TO_MARK_ATTACHMENT) {
 | 
| +    if (!ParseAnchorArrayTable(file, data + offset_type_specific_array,
 | 
| +                               length - offset_type_specific_array,
 | 
| +                               class_count)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to parse anchor array");
 | 
| +    }
 | 
| +  } else if (type == GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT) {
 | 
| +    if (!ParseLigatureArrayTable(file, data + offset_type_specific_array,
 | 
| +                                 length - offset_type_specific_array,
 | 
| +                                 class_count)) {
 | 
| +      return OTS_FAILURE_MSG("Failed to parse ligature array");
 | 
| +    }
 | 
| +  } else {
 | 
| +    return OTS_FAILURE_MSG("Bad attachment type %d", type);
 | 
| +  }
 | 
| +
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +// Lookup Type 4:
 | 
| +// MarkToBase Attachment Positioning Subtable
 | 
| +bool ParseMarkToBaseAttachment(const ots::OpenTypeFile *file,
 | 
| +                               const uint8_t *data, const size_t length) {
 | 
| +  return ParseMarkToAttachmentSubtables(file, data, length,
 | 
| +                                        GPOS_TYPE_MARK_TO_BASE_ATTACHMENT);
 | 
| +}
 | 
| +
 | 
| +// Lookup Type 5:
 | 
| +// MarkToLigature Attachment Positioning Subtable
 | 
| +bool ParseMarkToLigatureAttachment(const ots::OpenTypeFile *file,
 | 
| +                                   const uint8_t *data, const size_t length) {
 | 
| +  return ParseMarkToAttachmentSubtables(file, data, length,
 | 
| +                                        GPOS_TYPE_MARK_TO_LIGATURE_ATTACHMENT);
 | 
| +}
 | 
| +
 | 
| +// Lookup Type 6:
 | 
| +// MarkToMark Attachment Positioning Subtable
 | 
| +bool ParseMarkToMarkAttachment(const ots::OpenTypeFile *file,
 | 
| +                               const uint8_t *data, const size_t length) {
 | 
| +  return ParseMarkToAttachmentSubtables(file, data, length,
 | 
| +                                        GPOS_TYPE_MARK_TO_MARK_ATTACHMENT);
 | 
| +}
 | 
| +
 | 
| +// Lookup Type 7:
 | 
| +// Contextual Positioning Subtables
 | 
| +bool ParseContextPositioning(const ots::OpenTypeFile *file,
 | 
| +                             const uint8_t *data, const size_t length) {
 | 
| +  return ots::ParseContextSubtable(file, data, length, file->maxp->num_glyphs,
 | 
| +                                   file->gpos->num_lookups);
 | 
| +}
 | 
| +
 | 
| +// Lookup Type 8:
 | 
| +// Chaining Contexual Positioning Subtable
 | 
| +bool ParseChainedContextPositioning(const ots::OpenTypeFile *file,
 | 
| +                                    const uint8_t *data, const size_t length) {
 | 
| +  return ots::ParseChainingContextSubtable(file, data, length,
 | 
| +                                           file->maxp->num_glyphs,
 | 
| +                                           file->gpos->num_lookups);
 | 
| +}
 | 
| +
 | 
| +// Lookup Type 9:
 | 
| +// Extension Positioning
 | 
| +bool ParseExtensionPositioning(const ots::OpenTypeFile *file,
 | 
| +                               const uint8_t *data, const size_t length) {
 | 
| +  return ots::ParseExtensionSubtable(file, data, length,
 | 
| +                                     &kGposLookupSubtableParser);
 | 
| +}
 | 
| +
 | 
| +}  // namespace
 | 
| +
 | 
| +#define DROP_THIS_TABLE(msg_) \
 | 
| +  do { \
 | 
| +    OTS_FAILURE_MSG(msg_ ", table discarded"); \
 | 
| +    file->gpos->data = 0; \
 | 
| +    file->gpos->length = 0; \
 | 
| +  } while (0)
 | 
| +
 | 
| +namespace ots {
 | 
| +
 | 
| +// As far as I checked, following fonts contain invalid GPOS table and
 | 
| +// OTS will drop their GPOS table.
 | 
| +//
 | 
| +// # invalid delta format in device table
 | 
| +// samanata.ttf
 | 
| +//
 | 
| +// # bad size range in device table
 | 
| +// Sarai_07.ttf
 | 
| +//
 | 
| +// # bad offset to PairSetTable
 | 
| +// chandas1-2.ttf
 | 
| +//
 | 
| +// # bad offset to FeatureTable
 | 
| +// glrso12.ttf
 | 
| +// gllr12.ttf
 | 
| +// glbo12.ttf
 | 
| +// glb12.ttf
 | 
| +// glro12.ttf
 | 
| +// glbso12.ttf
 | 
| +// glrc12.ttf
 | 
| +// glrsc12.ttf
 | 
| +// glbs12.ttf
 | 
| +// glrs12.ttf
 | 
| +// glr12.ttf
 | 
| +//
 | 
| +// # ScriptRecords aren't sorted by tag
 | 
| +// Garogier_unhinted.otf
 | 
| +//
 | 
| +// # bad start coverage index in CoverageFormat2
 | 
| +// AndBasR.ttf
 | 
| +// CharisSILB.ttf
 | 
| +// CharisSILBI.ttf
 | 
| +// CharisSILI.ttf
 | 
| +// CharisSILR.ttf
 | 
| +// DoulosSILR.ttf
 | 
| +// GenBasBI.ttf
 | 
| +// GenBasI.ttf
 | 
| +// GenBkBasI.ttf
 | 
| +// GenBkBasB.ttf
 | 
| +// GenBkBasR.ttf
 | 
| +// Padauk-Bold.ttf
 | 
| +// Padauk.ttf
 | 
| +//
 | 
| +// # Contour point indexes aren't sorted
 | 
| +// Arial Unicode.ttf
 | 
| +
 | 
| +bool ots_gpos_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
 | 
| +  // Parsing GPOS table requires num_glyphs which is contained in maxp table.
 | 
| +  if (!file->maxp) {
 | 
| +    return OTS_FAILURE_MSG("missing maxp table needed in GPOS");
 | 
| +  }
 | 
| +
 | 
| +  Buffer table(data, length);
 | 
| +
 | 
| +  OpenTypeGPOS *gpos = new OpenTypeGPOS;
 | 
| +  file->gpos = gpos;
 | 
| +
 | 
| +  uint32_t version = 0;
 | 
| +  uint16_t offset_script_list = 0;
 | 
| +  uint16_t offset_feature_list = 0;
 | 
| +  uint16_t offset_lookup_list = 0;
 | 
| +  if (!table.ReadU32(&version) ||
 | 
| +      !table.ReadU16(&offset_script_list) ||
 | 
| +      !table.ReadU16(&offset_feature_list) ||
 | 
| +      !table.ReadU16(&offset_lookup_list)) {
 | 
| +    DROP_THIS_TABLE("Incomplete table");
 | 
| +    return true;
 | 
| +  }
 | 
| +
 | 
| +  if (version != 0x00010000) {
 | 
| +    DROP_THIS_TABLE("Bad version");
 | 
| +    return true;
 | 
| +  }
 | 
| +
 | 
| +  if (offset_lookup_list) {
 | 
| +    if (offset_lookup_list < kGposHeaderSize || offset_lookup_list >= length) {
 | 
| +      DROP_THIS_TABLE("Bad lookup list offset in table header");
 | 
| +      return true;
 | 
| +    }
 | 
| +
 | 
| +    if (!ParseLookupListTable(file, data + offset_lookup_list,
 | 
| +                              length - offset_lookup_list,
 | 
| +                              &kGposLookupSubtableParser,
 | 
| +                              &gpos->num_lookups)) {
 | 
| +      DROP_THIS_TABLE("Failed to parse lookup list table");
 | 
| +      return true;
 | 
| +    }
 | 
| +  }
 | 
| +
 | 
| +  uint16_t num_features = 0;
 | 
| +  if (offset_feature_list) {
 | 
| +    if (offset_feature_list < kGposHeaderSize || offset_feature_list >= length) {
 | 
| +      DROP_THIS_TABLE("Bad feature list offset in table header");
 | 
| +      return true;
 | 
| +    }
 | 
| +
 | 
| +    if (!ParseFeatureListTable(file, data + offset_feature_list,
 | 
| +                               length - offset_feature_list, gpos->num_lookups,
 | 
| +                               &num_features)) {
 | 
| +      DROP_THIS_TABLE("Failed to parse feature list table");
 | 
| +      return true;
 | 
| +    }
 | 
| +  }
 | 
| +
 | 
| +  if (offset_script_list) {
 | 
| +    if (offset_script_list < kGposHeaderSize || offset_script_list >= length) {
 | 
| +      DROP_THIS_TABLE("Bad script list offset in table header");
 | 
| +      return true;
 | 
| +    }
 | 
| +
 | 
| +    if (!ParseScriptListTable(file, data + offset_script_list,
 | 
| +                              length - offset_script_list, num_features)) {
 | 
| +      DROP_THIS_TABLE("Failed to parse script list table");
 | 
| +      return true;
 | 
| +    }
 | 
| +  }
 | 
| +
 | 
| +  gpos->data = data;
 | 
| +  gpos->length = length;
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +bool ots_gpos_should_serialise(OpenTypeFile *file) {
 | 
| +  return file->gpos != NULL && file->gpos->data != NULL;
 | 
| +}
 | 
| +
 | 
| +bool ots_gpos_serialise(OTSStream *out, OpenTypeFile *file) {
 | 
| +  if (!out->Write(file->gpos->data, file->gpos->length)) {
 | 
| +    return OTS_FAILURE_MSG("Failed to write GPOS table");
 | 
| +  }
 | 
| +
 | 
| +  return true;
 | 
| +}
 | 
| +
 | 
| +void ots_gpos_free(OpenTypeFile *file) {
 | 
| +  delete file->gpos;
 | 
| +}
 | 
| +
 | 
| +}  // namespace ots
 | 
| +
 | 
| +#undef TABLE_NAME
 | 
| +#undef DROP_THIS_TABLE
 | 
| 
 |