Correct decoder output table ordering

src/font.cc

@@ -217,7 +217,7 @@ size_t FontCollectionFileSize(const FontCollection& font_collection) {
 
 bool WriteFont(const Font& font, uint8_t* dst, size_t dst_size) {
   size_t offset = 0;
-  return WriteFont(font, &offset, dst, dst_size, true);
+  return WriteFont(font, &offset, dst, dst_size);
 }
 
 bool WriteTable(const Font::Table& table, size_t* offset, uint8_t* dst,
@@ -246,7 +246,7 @@ bool WriteTable(const Font::Table& table, size_t* offset, uint8_t* dst,
 }
 
 bool WriteFont(const Font& font, size_t* offset, uint8_t* dst,
-               size_t dst_size, bool reorder_tables) {
+               size_t dst_size) {
   if (dst_size < 12ULL + 16ULL * font.num_tables) {
     return FONT_COMPRESSION_FAILURE();
   }
@@ -258,19 +258,13 @@ bool WriteFont(const Font& font, size_t* offset, uint8_t* dst,
   Store16(search_range, offset, dst);
   Store16(max_pow2, offset, dst);
   Store16(range_shift, offset, dst);
-  if (reorder_tables) {
-    for (const auto tag : font.OutputOrderedTags()) {
-      if (!WriteTable(font.tables.at(tag), offset, dst, dst_size)) {
-        return false;
-      }
-    }
-  } else {
-    for (const auto& i : font.tables) {
-      if (!WriteTable(i.second, offset, dst, dst_size)) {
-        return false;
-      }
+
+  for (const auto& i : font.tables) {
+    if (!WriteTable(i.second, offset, dst, dst_size)) {
+      return false;
     }
   }
+
   return true;
 }
 
@@ -280,7 +274,7 @@ bool WriteFontCollection(const FontCollection& font_collection, uint8_t* dst,
 
   // It's simpler if this just a simple sfnt
   if (font_collection.fonts.size() == 1) {
-    return WriteFont(font_collection.fonts[0], &offset, dst, dst_size, true);
+    return WriteFont(font_collection.fonts[0], &offset, dst, dst_size);
   }
 
   // Write TTC header
@@ -304,7 +298,7 @@ bool WriteFontCollection(const FontCollection& font_collection, uint8_t* dst,
   for (int i = 0; i < font_collection.fonts.size(); i++) {
     const auto& font = font_collection.fonts[i];
     StoreU32(offset, &offset_table, dst);
-    if (!WriteFont(font, &offset, dst, dst_size, false)) {
+    if (!WriteFont(font, &offset, dst, dst_size)) {
       return false;
     }
   }

src/font.h

@@ -83,9 +83,8 @@ size_t FontCollectionFileSize(const FontCollection& font);
 // same as returned by FontFileSize(). Returns false upon buffer overflow (which
 // should not happen if dst_size was computed by FontFileSize()).
 bool WriteFont(const Font& font, uint8_t* dst, size_t dst_size);
-// Write the font at a specific offset, optionally reordering tables
-bool WriteFont(const Font& font, size_t* offset, uint8_t* dst, size_t dst_size,
-               bool reorder_tables);
+// Write the font at a specific offset
+bool WriteFont(const Font& font, size_t* offset, uint8_t* dst, size_t dst_size);
 
 bool WriteFontCollection(const FontCollection& font_collection, uint8_t* dst,
                          size_t dst_size);

src/woff2_common.h

@@ -52,6 +52,10 @@ struct Table {
   uint32_t dst_offset;
   uint32_t dst_length;
   const uint8_t* dst_data;
+
+  bool operator<(const Table& other) const {
+    return tag < other.tag;
+  }
 };
 
 

src/woff2_dec.cc

@@ -17,6 +17,7 @@
 #include "./woff2_dec.h"
 
 #include <stdlib.h>
+#include <algorithm>
 #include <complex>
 #include <cstring>
 #include <limits>
@@ -932,6 +933,24 @@ bool ConvertWOFF2ToTTF(uint8_t* result, size_t result_length,
     return FONT_COMPRESSION_FAILURE();
   }
 
+  // Re-order tables in output (OTSpec) order
+  if (header_version) {
+    // collection; we have to sort the table offset vector in each font
+    for (auto& ttc_font : ttc_fonts) {
+      std::map<uint32_t, uint16_t> sorted_index_by_tag;
+      for (auto table_index : ttc_font.table_indices) {
+        sorted_index_by_tag[tables[table_index].tag] = table_index;
+      }
+      uint16_t index = 0;
+      for (auto& i : sorted_index_by_tag) {
+        ttc_font.table_indices[index++] = i.second;
+      }
+    }
+  } else {
+    // non-collection; we can just sort the tables
+    std::sort(tables.begin(), tables.end());
+  }
+
   // Start building the font
   size_t offset = 0;
   size_t offset_table = 0;