Updating to new OTS repo from https://github.com/khaledhosny/ots.git

src/post.cc

 // Copyright (c) 2009 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 "post.h"
 
 #include "maxp.h"
 
 // post - PostScript
-// http://www.microsoft.com/opentype/otspec/post.htm
+// http://www.microsoft.com/typography/otspec/post.htm
+
+#define TABLE_NAME "post"
 
 namespace ots {
 
 bool ots_post_parse(OpenTypeFile *file, const uint8_t *data, size_t length) {
   Buffer table(data, length);
 
   OpenTypePOST *post = new OpenTypePOST;
   file->post = post;
 
   if (!table.ReadU32(&post->version) ||
       !table.ReadU32(&post->italic_angle) ||
       !table.ReadS16(&post->underline) ||
       !table.ReadS16(&post->underline_thickness) ||
       !table.ReadU32(&post->is_fixed_pitch)) {
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("Failed to read post header");
   }
 
   if (post->underline_thickness < 0) {
     post->underline_thickness = 1;
   }
 
   if (post->version == 0x00010000) {
     return true;
   } else if (post->version == 0x00030000) {
     return true;
   } else if (post->version != 0x00020000) {
     // 0x00025000 is deprecated. We don't accept it.
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("Bad post version %x", post->version);
   }
 
   // We have a version 2 table with a list of Pascal strings at the end
 
   // We don't care about the memory usage fields. We'll set all these to zero
   // when serialising
   if (!table.Skip(16)) {
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("Failed to skip memory usage in post table");
   }
 
   uint16_t num_glyphs = 0;
   if (!table.ReadU16(&num_glyphs)) {
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("Failed to read number of glyphs");
   }
 
   if (!file->maxp) {
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("No maxp table required by post table");
   }
 
   if (num_glyphs == 0) {
     if (file->maxp->num_glyphs > 258) {
-      return OTS_FAILURE();
+      return OTS_FAILURE_MSG("Can't have no glyphs in the post table if there are more than 256 glyphs in the font");
     }
     OTS_WARNING("table version is 1, but no glyf names are found");
     // workaround for fonts in http://www.fontsquirrel.com/fontface
     // (e.g., yataghan.ttf).
     post->version = 0x00010000;
     return true;
   }
 
   if (num_glyphs != file->maxp->num_glyphs) {
     // Note: Fixedsys500c.ttf seems to have inconsistent num_glyphs values.
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("Bad number of glyphs in post table %d", num_glyphs);
   }
 
   post->glyph_name_index.resize(num_glyphs);
   for (unsigned i = 0; i < num_glyphs; ++i) {
     if (!table.ReadU16(&post->glyph_name_index[i])) {
-      return OTS_FAILURE();
+      return OTS_FAILURE_MSG("Failed to read post information for glyph %d", i);
     }
     // Note: A strict interpretation of the specification requires name indexes
     // are less than 32768. This, however, excludes fonts like unifont.ttf
     // which cover all of unicode.
   }
 
   // Now we have an array of Pascal strings. We have to check that they are all
   // valid and read them in.
   const size_t strings_offset = table.offset();
   const uint8_t *strings = data + strings_offset;
   const uint8_t *strings_end = data + length;
 
   for (;;) {
     if (strings == strings_end) break;
     const unsigned string_length = *strings;
     if (strings + 1 + string_length > strings_end) {
-      return OTS_FAILURE();
+      return OTS_FAILURE_MSG("Bad string length %d", string_length);
     }
     if (std::memchr(strings + 1, '\0', string_length)) {
-      return OTS_FAILURE();
+      return OTS_FAILURE_MSG("Bad string of length %d", string_length);
     }
     post->names.push_back(
         std::string(reinterpret_cast<const char*>(strings + 1), string_length));
     strings += 1 + string_length;
   }
   const unsigned num_strings = post->names.size();
 
   // check that all the references are within bounds
   for (unsigned i = 0; i < num_glyphs; ++i) {
     unsigned offset = post->glyph_name_index[i];
     if (offset < 258) {
       continue;
     }
 
     offset -= 258;
     if (offset >= num_strings) {
-      return OTS_FAILURE();
+      return OTS_FAILURE_MSG("Bad string index %d", offset);
     }
   }
 
   return true;
 }
 
 bool ots_post_should_serialise(OpenTypeFile *file) {
   return file->post != NULL;
 }
 
 bool ots_post_serialise(OTSStream *out, OpenTypeFile *file) {
   const OpenTypePOST *post = file->post;
 
   // OpenType with CFF glyphs must have v3 post table.
   if (file->post && file->cff && file->post->version != 0x00030000) {
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("Bad post version %x", post->version);
   }
 
   if (!out->WriteU32(post->version) ||
       !out->WriteU32(post->italic_angle) ||
       !out->WriteS16(post->underline) ||
       !out->WriteS16(post->underline_thickness) ||
       !out->WriteU32(post->is_fixed_pitch) ||
       !out->WriteU32(0) ||
       !out->WriteU32(0) ||
       !out->WriteU32(0) ||
       !out->WriteU32(0)) {
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("Failed to write post header");
   }
 
   if (post->version != 0x00020000) {
     return true;  // v1.0 and v3.0 does not have glyph names.
   }
 
   const uint16_t num_indexes =
       static_cast<uint16_t>(post->glyph_name_index.size());
   if (num_indexes != post->glyph_name_index.size() ||
       !out->WriteU16(num_indexes)) {
-    return OTS_FAILURE();
+    return OTS_FAILURE_MSG("Failed to write number of indices");
   }
 
   for (uint16_t i = 0; i < num_indexes; ++i) {
     if (!out->WriteU16(post->glyph_name_index[i])) {
-      return OTS_FAILURE();
+      return OTS_FAILURE_MSG("Failed to write name index %d", i);
     }
   }
 
   // Now we just have to write out the strings in the correct order
   for (unsigned i = 0; i < post->names.size(); ++i) {
     const std::string& s = post->names[i];
     const uint8_t string_length = static_cast<uint8_t>(s.size());
     if (string_length != s.size() ||
         !out->Write(&string_length, 1)) {
-      return OTS_FAILURE();
+      return OTS_FAILURE_MSG("Failed to write string %d", i);
     }
     // Some ttf fonts (e.g., frank.ttf on Windows Vista) have zero-length name.
     // We allow them.
     if (string_length > 0 && !out->Write(s.data(), string_length)) {
-      return OTS_FAILURE();
+      return OTS_FAILURE_MSG("Failed to write string length for string %d", i);
     }
   }
 
   return true;
 }
 
 void ots_post_free(OpenTypeFile *file) {
   delete file->post;
 }
 
 }  // namespace ots
+
+#undef TABLE_NAME