commit f6cb7152c208
Author: Mats Palmgren <mats@mozilla.com>
Date:   Tue Jan 23 00:00:03 2018 +0100

    Bug 1431781 - Report at least OverflowIncomplete reflow status when we skip reflowing OverflowContainer children and have a next-in-flow.  r=dholbert a=lizzard
    
    --HG--
    extra : source : cef7ac1c276ba50a6789ca916568434dbc6990ae
---
 layout/generic/nsContainerFrame.cpp | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git layout/generic/nsContainerFrame.cpp layout/generic/nsContainerFrame.cpp
index d50e1fc6f613..732f24e00b1d 100644
--- layout/generic/nsContainerFrame.cpp
+++ layout/generic/nsContainerFrame.cpp
@@ -1160,6 +1160,13 @@ nsContainerFrame::ReflowOverflowContainerChildren(nsPresContext*           aPres
     if (frame->GetPrevInFlow()->GetParent() != GetPrevInFlow()) {
       // frame's prevInFlow has moved, skip reflowing this frame;
       // it will get reflowed once it's been placed
+      if (GetNextInFlow()) {
+        // We report OverflowIncomplete status in this case to avoid our parent
+        // deleting our next-in-flows which might destroy non-empty frames.
+        nsReflowStatus status;
+        status.SetOverflowIncomplete();
+        aStatus.MergeCompletionStatusFrom(status);
+      }
       continue;
     }
     // If the available vertical height has changed, we need to reflow