From 43f5edb6f8daece2797adc10947e19844dfa14ba Mon Sep 17 00:00:00 2001
From: "qianyuan.wqy" <qianyuan.wqy@taobao.com>
Date: Wed, 9 Oct 2019 11:05:13 +0800
Subject: [PATCH] Add clearBFCs method and clear BFCs after self-layout of
 scroller node.

---
 ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm | 5 +++++
 weex_core/Source/core/layout/layout.h                    | 4 ++++
 2 files changed, 9 insertions(+)

diff --git a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
index 4d3f4c9110..981a7afe65 100644
--- a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
+++ b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
@@ -1152,6 +1152,11 @@ - (void)_layoutPlatform
             _flexCssNode->calculateLayout(renderPageSize);
             _flexCssNode->setParent(parent, _flexCssNode);
             
+            /* We must clear BFCs becuase we have set parent of _flexCSSNode to nullptr and
+             manually called its calculateLayout method. This will cause a non-bfc layout node
+             to have items in its BFCs vector. Later, a wild pointer may cause crash. */
+            _flexCssNode->clearBFCs();
+            
             // set origin and size back
             _flexCssNode->rewriteLayoutResult(left, top, width, height);
         }
diff --git a/weex_core/Source/core/layout/layout.h b/weex_core/Source/core/layout/layout.h
index 621797224e..e8d58f7d33 100644
--- a/weex_core/Source/core/layout/layout.h
+++ b/weex_core/Source/core/layout/layout.h
@@ -731,6 +731,10 @@ namespace WeexCore {
       
       markDirty();
     }
+      
+    inline void clearBFCs() {
+        BFCs.clear();
+    }
 
     inline void addChildAt(WXCoreLayoutNode* const child, Index index) {
       mChildList.insert(mChildList.begin() + index, child);