Coverity fixes to keep coverity quiet....

courgette/courgette_tool.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 <vector>
 #include <string>
 
 #include "base/at_exit.h"
 #include "base/basictypes.h"
 #include "base/command_line.h"
@@ skipping 199 matching lines @@
     Problem("Can't serialize encoded program.");
   courgette::DeleteEncodedProgram(encoded_program);
 
   courgette::SinkStreamSet model_sinks;
   const courgette::Status write_model_status =
     courgette::WriteEncodedProgram(encoded_model, &model_sinks);
   if (write_model_status != courgette::C_OK)
     Problem("Can't serialize encoded model.");
   courgette::DeleteEncodedProgram(encoded_model);
 
+  courgette::SinkStream empty_sink;
   for (int i = 0;  ; ++i) {
     courgette::SinkStream* old_stream = model_sinks.stream(i);
     courgette::SinkStream* new_stream = program_sinks.stream(i);
-    if (old_stream == NULL  && new_stream == NULL)
+    if (old_stream == NULL && new_stream == NULL)
       break;
 
     courgette::SourceStream old_source;
     courgette::SourceStream new_source;
-    old_source.Init(*old_stream);
-    new_source.Init(*new_stream);
+    old_source.Init(old_stream ? *old_stream : empty_sink);
+    new_source.Init(new_stream ? *new_stream : empty_sink);
     courgette::SinkStream patch_stream;
     courgette::BSDiffStatus status =
         courgette::CreateBinaryPatch(&old_source, &new_source, &patch_stream);
     if (status != courgette::OK) Problem("-xxx failed.");
 
     WriteSinkToFile(&patch_stream,
                     output_file_root + L"-" + IntToWString(i));
   }
 }
 
@@ skipping 168 matching lines @@
     } else if (cmd_spread_1_adjusted || cmd_spread_1_unadjusted) {
       if (values.size() != 3)
         UsageProblem("-gen1[au] <old_file> <new_file> <patch_files_root>");
       DisassembleAdjustDiff(values[0], values[1], values[2],
                             cmd_spread_1_adjusted);
     } else {
       UsageProblem("No operation specified");
     }
   }
 }