Fix CFX_RetainPtr move-assign semantics.

Ensure moved value becomes a nullptr after the move.
Update comment while we're at it.

Change-Id: I7a2999d5f5c5142cc7826cd7880b1e2317b5445f
Reviewed-on: https://pdfium-review.googlesource.com/3163
Commit-Queue: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/core/fxcrt/cfx_retain_ptr_unittest.cpp b/core/fxcrt/cfx_retain_ptr_unittest.cpp
index 3168b5a4c7..f097b4b28c 100644
--- a/core/fxcrt/cfx_retain_ptr_unittest.cpp
+++ b/core/fxcrt/cfx_retain_ptr_unittest.cpp
@@ -65,6 +65,8 @@ TEST(fxcrt, RetainPtrMoveCtor) {
     CFX_RetainPtr<PseudoRetainable> ptr1(&obj);
     {
       CFX_RetainPtr<PseudoRetainable> ptr2(std::move(ptr1));
+      EXPECT_EQ(nullptr, ptr1.Get());
+      EXPECT_EQ(&obj, ptr2.Get());
       EXPECT_EQ(1, obj.retain_count());
       EXPECT_EQ(0, obj.release_count());
     }
@@ -185,6 +187,27 @@ TEST(fxcrt, RetainPtrAssign) {
   EXPECT_EQ(2, obj.release_count());
 }
 
+TEST(fxcrt, RetainPtrMoveAssign) {
+  PseudoRetainable obj;
+  {
+    CFX_RetainPtr<PseudoRetainable> ptr1(&obj);
+    {
+      CFX_RetainPtr<PseudoRetainable> ptr2;
+      EXPECT_EQ(&obj, ptr1.Get());
+      EXPECT_EQ(nullptr, ptr2.Get());
+      ptr2 = std::move(ptr1);
+      EXPECT_EQ(nullptr, ptr1.Get());
+      EXPECT_EQ(&obj, ptr2.Get());
+      EXPECT_EQ(1, obj.retain_count());
+      EXPECT_EQ(0, obj.release_count());
+    }
+    EXPECT_EQ(1, obj.retain_count());
+    EXPECT_EQ(1, obj.release_count());
+  }
+  EXPECT_EQ(1, obj.retain_count());
+  EXPECT_EQ(1, obj.release_count());
+}
+
 TEST(fxcrt, RetainPtrEquals) {
   PseudoRetainable obj1;
   PseudoRetainable obj2;