reduce scope of task group

The code was normally fine, but potentially problematic depending on
thread provider to delete the thread pool prior to waiting for all the
tasks to finish

Signed-off-by: Kimball Thurston <[email protected]>

Author: kdt3rd

src/test/OpenEXRTest/testMultiPartThreading.cpp

@@ -620,17 +620,19 @@ generateRandomFile (int partCount, const std::string& fn)
     //
     // Writing tasks.
     //
-    TaskGroup                taskGroup;
     ThreadPool*              threadPool = new ThreadPool (32);
-    vector<WritingTaskData*> list;
-    for (int i = 0; i < taskListSize; i++)
     {
-        list.push_back (&taskList[i]);
-        if (i % 10 == 0 || i == taskListSize - 1)
+        TaskGroup                taskGroup;
+        vector<WritingTaskData*> list;
+        for (int i = 0; i < taskListSize; i++)
         {
-            threadPool->addTask (
-                (new WritingTask (&taskGroup, &file, list, tiledFrameBuffers)));
-            list.clear ();
+            list.push_back (&taskList[i]);
+            if (i % 10 == 0 || i == taskListSize - 1)
+            {
+                threadPool->addTask (
+                    (new WritingTask (&taskGroup, &file, list, tiledFrameBuffers)));
+                list.clear ();
+            }
         }
     }