Bug 1362303 - Don't use a Shmem we failed to allocate in nsContentUtils. r=Bas

2017-05-15 12:15:48 +02:00
parent dfa37f98c7
commit 70f7fd76f9
3 changed files with 34 additions and 24 deletions
--- a/widget/nsDragServiceProxy.cpp
+++ b/widget/nsDragServiceProxy.cpp
@@ -55,9 +55,16 @@ nsDragServiceProxy::InvokeDragSessionImpl(nsIArray* aArrayTransferables,
      if (dataSurface) {
        size_t length;
        int32_t stride;
-        Shmem surfaceData;
-        nsContentUtils::GetSurfaceData(dataSurface, &length, &stride, child,
-                                       &surfaceData);
+        Maybe<Shmem> maybeShm = nsContentUtils::GetSurfaceData(dataSurface,
+                                                               &length,
+                                                               &stride,
+                                                               child);
+        if (maybeShm.isNothing()) {
+          return NS_ERROR_FAILURE;
+        }
+
+        auto surfaceData = maybeShm.value();
+
        // Save the surface data to shared memory.
        if (!surfaceData.IsReadable() || !surfaceData.get<char>()) {
          NS_WARNING("Failed to create shared memory for drag session.");