control depth of collectGroups so avoid overrunning data tokens after a nested group.

Author: tmontgomery

sbe-tool/src/main/java/uk/co/real_logic/sbe/ir/GenerationUtil.java

@@ -51,15 +51,21 @@ public static int collectGroups(final List<Token> tokens, final int index, final
  {
  int groupStart = -1;
  int groupEnd = -1;
+ int depth = 0;
  for (int i = index, size = tokens.size(); i < size; i++)
  {
  final Token token = tokens.get(i);
- if (Signal.BEGIN_GROUP == token.signal() && -1 == groupStart)
+ if (Signal.BEGIN_GROUP == token.signal())
  {
- groupStart = i;
+ if (-1 == groupStart)
+ {
+ groupStart = i;
+ }
+
+ depth++;
  }
 
- if (Signal.END_GROUP == token.signal())
+ if (Signal.END_GROUP == token.signal() && --depth >= 0)
  {
  groupEnd = i;
  }

sbe-tool/src/test/cpp/GroupWithDataTest.cpp

@@ -18,6 +18,7 @@
 #include "gtest/gtest.h"
 #include "group_with_data/TestMessage1.hpp"
 #include "group_with_data/TestMessage2.hpp"
+#include "group_with_data/TestMessage3.hpp"
 #include "group_with_data/TestMessage4.hpp"
 
 using namespace std;
@@ -128,6 +129,7 @@ class GroupWithDataTest : public testing::Test
 
  TestMessage1 msg1_;
  TestMessage2 msg2_;
+ TestMessage3 msg3_;
  TestMessage4 msg4_;
 };