Bug 1415083 - Rearrange the declaration of objects to avoid stack-use-after-scope. r=froydnj

MozReview-Commit-ID: 7nMw1i10b7e

--HG--
extra : rebase_source : ab23ef60ff800f522357037cacd02bf87d2960ee

xpcom/tests/gtest/TestTArray.cpp

@@ -144,12 +144,12 @@ TEST(TArray, AssignmentOperatorSelfAssignment)
 
 TEST(TArray, CopyOverlappingForwards)
 {
-  nsTArray<Movable> array;
   const size_t rangeLength = 8;
   const size_t initialLength = 2 * rangeLength;
+  uint32_t destructionCounters[initialLength];
+  nsTArray<Movable> array;
   array.AppendElements(initialLength);
 
-  uint32_t destructionCounters[initialLength];
   for (uint32_t i = 0; i < initialLength; ++i) {
     destructionCounters[i] = 0;
   }
@@ -172,9 +172,10 @@ TEST(TArray, CopyOverlappingForwards)
 // destroy all over the source elements being copied.
 TEST(TArray, CopyOverlappingBackwards)
 {
-  nsTArray<Copyable> array;
   const size_t rangeLength = 8;
   const size_t initialLength = 2 * rangeLength;
+  uint32_t destructionCounters[initialLength];
+  nsTArray<Copyable> array;
   array.SetCapacity(3 * rangeLength);
   array.AppendElements(initialLength);
   // To tickle the bug, we need to copy a source region:
@@ -188,7 +189,6 @@ TEST(TArray, CopyOverlappingBackwards)
   // so we are forced to copy back-to-front to ensure correct behavior.
   // The easiest way to do that is to call InsertElementsAt, which will force
   // the desired kind of shift.
-  uint32_t destructionCounters[initialLength];
   for (uint32_t i = 0; i < initialLength; ++i) {
     destructionCounters[i] = 0;
   }