Fix an off-by-one error in deoptimization compression.

runtime/vm/deopt_instructions.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/deopt_instructions.h"
 
 #include "vm/assembler.h"
 #include "vm/code_patcher.h"
 #include "vm/intermediate_language.h"
 #include "vm/locations.h"
@@ skipping 1000 matching lines @@
     MaterializeObjectInstr* mat) const {
   for (intptr_t i = 0; i < materializations_.length(); i++) {
     if (materializations_[i] == mat) {
       return i;
     }
   }
   return -1;
 }
 
 
-RawDeoptInfo* DeoptInfoBuilder::CreateDeoptInfo() {
+RawDeoptInfo* DeoptInfoBuilder::CreateDeoptInfo(const Array& deopt_table) {
   // TODO(vegorov): enable compression of deoptimization info containing object
   // materialization instructions.
   const bool disable_compression =
       (instructions_[0]->kind() == DeoptInstr::kMaterializeObject);
 
   intptr_t length = instructions_.length();
 
   // Count the number of instructions that are a shared suffix of some deopt
   // info already written.
   TrieNode* suffix = trie_root_;
@@ skipping 15 matching lines @@
   // Write the unshared instructions and build their sub-tree.
   TrieNode* node = NULL;
   intptr_t write_count = (suffix_length > 1) ? length - 1 : length;
   for (intptr_t i = 0; i < write_count; ++i) {
     DeoptInstr* instr = instructions_[i];
     deopt_info.SetAt(i, instr->kind(), instr->from_index());
     TrieNode* child = node;
     node = new TrieNode(instr, current_info_number_);
     node->AddChild(child);
   }
-  suffix->AddChild(node);
 
   if (suffix_length > 1) {
+    suffix->AddChild(node);
     DeoptInstr* instr =
         new DeoptSuffixInstr(suffix->info_number(), suffix_length);
     deopt_info.SetAt(length - 1, instr->kind(), instr->from_index());
+  } else {
+    trie_root_->AddChild(node);
   }
 
+  ASSERT(deopt_info.VerifyDecompression(instructions_, deopt_table));
   instructions_.Clear();
   materializations_.Clear();
   frame_start_ = -1;
 
   ++current_info_number_;
   return deopt_info.raw();
 }
 
 
 intptr_t DeoptTable::SizeFor(intptr_t length) {
@@ skipping 24 matching lines @@
                           Smi* offset,
                           DeoptInfo* info,
                           Smi* reason) {
   intptr_t i = index * kEntrySize;
   *offset ^= table.At(i);
   *info ^= table.At(i + 1);
   *reason ^= table.At(i + 2);
 }
 
 }  // namespace dart