libui: Clean up Fence and Region flattening

Fence was flattening incorrectly, causing issues with any fields
flattened after it, and Region was relying on being the last object
flattened. This change addresses both.

Change-Id: If49de061de6e2f11f4d846b4d8c18627dfb7e109

1 files changed, 4 insertions, 2 deletions

diff --git a/libs/ui/Fence.cpp b/libs/ui/Fence.cpp
index 9cf2881787..bf24ffb7e0 100644
--- a/libs/ui/Fence.cpp
+++ b/libs/ui/Fence.cpp
@@ -130,7 +130,7 @@ nsecs_t Fence::getSignalTime() const {
 }
 
 size_t Fence::getFlattenedSize() const {
-    return 1;
+    return 4;
 }
 
 size_t Fence::getFdCount() const {
@@ -141,7 +141,9 @@ status_t Fence::flatten(void*& buffer, size_t& size, int*& fds, size_t& count) c
     if (size < getFlattenedSize() || count < getFdCount()) {
         return NO_MEMORY;
     }
-    FlattenableUtils::write(buffer, size, getFdCount());
+    // Cast to uint32_t since the size of a size_t can vary between 32- and
+    // 64-bit processes
+    FlattenableUtils::write(buffer, size, static_cast<uint32_t>(getFdCount()));
     if (isValid()) {
         *fds++ = mFenceFd;
         count--;