Fix Dart_GlobalTimelineGetTrace to null terminate the string

runtime/vm/dart_api_impl_test.cc

 // Copyright (c) 2012, 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 "bin/builtin.h"
 #include "include/dart_api.h"
 #include "include/dart_mirrors_api.h"
 #include "include/dart_native_api.h"
 #include "include/dart_tools_api.h"
 #include "platform/assert.h"
@@ skipping 9544 matching lines @@
 
   // Grab the trace.
   AppendData data;
   success = Dart_TimelineGetTrace(AppendStreamConsumer, &data);
   EXPECT(success);
   buffer = reinterpret_cast<char*>(data.buffer);
   buffer_length = data.buffer_length;
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"CompileFunction\"", buffer);
   EXPECT_SUBSTRING("\"function\":\"::_main\"", buffer);
 
   // Free buffer allocated by AppendStreamConsumer
   free(data.buffer);
 }
 
 
@@ skipping 27 matching lines @@
   AppendData data;
   data.buffer = NULL;
   data.buffer_length = 0;
   success = Dart_TimelineGetTrace(AppendStreamConsumer, &data);
   EXPECT(success);
   buffer = reinterpret_cast<char*>(data.buffer);
   buffer_length = data.buffer_length;
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"cat\":\"Dart\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"DART_NAME\"", buffer);
 
   // Free buffer allocated by AppendStreamConsumer
   free(data.buffer);
 }
 
 
 TEST_CASE(Timeline_Dart_TimelineGetTraceWithDartEvents) {
@@ skipping 25 matching lines @@
 
   // Grab the trace.
   AppendData data;
   success = Dart_TimelineGetTrace(AppendStreamConsumer, &data);
   EXPECT(success);
   buffer = reinterpret_cast<char*>(data.buffer);
   buffer_length = data.buffer_length;
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"CompileFunction\"", buffer);
   EXPECT_SUBSTRING("\"function\":\"::_main\"", buffer);
   EXPECT_SUBSTRING("\"cat\":\"Dart\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"DART_NAME\"", buffer);
 
   // Free buffer allocated by AppendStreamConsumer
   free(data.buffer);
 }
@@ skipping 23 matching lines @@
 
   // Grab the trace.
   AppendData data;
   success = Dart_TimelineGetTrace(AppendStreamConsumer, &data);
   EXPECT(success);
   buffer = reinterpret_cast<char*>(data.buffer);
   buffer_length = data.buffer_length;
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"CompileFunction\"", buffer);
   EXPECT_SUBSTRING("\"function\":\"::_main\"", buffer);
 
   // Free buffer allocated by AppendStreamConsumer
   free(data.buffer);
 }
 
 
@@ skipping 28 matching lines @@
 
   // Grab the global trace.
   AppendData data;
   success = Dart_GlobalTimelineGetTrace(AppendStreamConsumer, &data);
   EXPECT(success);
   buffer = reinterpret_cast<char*>(data.buffer);
   buffer_length = data.buffer_length;
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
 
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
+
   // Heartbeat test.
   EXPECT_SUBSTRING("\"name\":\"TestVMDuration\"", buffer);
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"CompileFunction\"", buffer);
   EXPECT_SUBSTRING("\"function\":\"::_main\"", buffer);
   EXPECT_NOTSUBSTRING("\"function\":\"::_bar\"", buffer);
 
   // Free buffer allocated by AppendStreamConsumer
   free(data.buffer);
   data.buffer = NULL;
@@ skipping 14 matching lines @@
                          NULL);
   }
 
   // Grab the global trace.
   success = Dart_GlobalTimelineGetTrace(AppendStreamConsumer, &data);
   EXPECT(success);
   buffer = reinterpret_cast<char*>(data.buffer);
   buffer_length = data.buffer_length;
   EXPECT(buffer_length > 0);
   EXPECT(buffer != NULL);
+  // Response starts with a '{' character and not a '['.
+  EXPECT(buffer[0] == '{');
+  // Response ends with a '}' character and not a ']'.
+  EXPECT(buffer[buffer_length - 1] == '\0');
+  EXPECT(buffer[buffer_length - 2] == '}');
 
   // Heartbeat test for old events.
   EXPECT_SUBSTRING("\"name\":\"TestVMDuration\"", buffer);
   EXPECT_SUBSTRING("\"cat\":\"Compiler\"", buffer);
   EXPECT_SUBSTRING("\"name\":\"CompileFunction\"", buffer);
   EXPECT_SUBSTRING("\"function\":\"::_main\"", buffer);
 
   // Heartbeat test for new events.
   EXPECT_SUBSTRING("\"name\":\"TestVMDuration2\"", buffer);
   EXPECT_SUBSTRING("\"function\":\"::_bar\"", buffer);
 
   // Free buffer allocated by AppendStreamConsumer
   free(data.buffer);
 }
 
 }  // namespace dart