From e9edd4d551f83ab71272dbd995e75129d8297a98 Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Tue, 9 Oct 2018 14:48:00 +0300
Subject: [PATCH] Fix avgRowHeight correcting bug

---
 DynamicVirtualScroll.js | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/DynamicVirtualScroll.js b/DynamicVirtualScroll.js
index 2bf7f12..bb5960e 100644
--- a/DynamicVirtualScroll.js
+++ b/DynamicVirtualScroll.js
@@ -111,10 +111,10 @@ export function virtualScrollDriver(props, oldState, getRenderedItemHeight)
             }
             sum += itemSize;
         }
-        if (sum + newState.lastItemsTotalHeight + newState.topPlaceholderHeight > newState.targetHeight)
+        const correctedAvg = (sum + newState.lastItemsTotalHeight) / (count + newState.viewportItemCount);
+        if (correctedAvg > newState.avgRowHeight)
         {
-            // avgRowHeight should be corrected
-            newState.avgRowHeight = (sum + newState.lastItemsTotalHeight) / (count + newState.viewportItemCount);
+            newState.avgRowHeight = correctedAvg;
         }
     }
     else
@@ -133,10 +133,10 @@ export function virtualScrollDriver(props, oldState, getRenderedItemHeight)
             sum += itemSize;
         }
         newState.middlePlaceholderHeight = newState.targetHeight - sum - newState.lastItemsTotalHeight - newState.topPlaceholderHeight;
-        if (newState.middlePlaceholderHeight < 0)
+        const correctedAvg = (sum + newState.lastItemsTotalHeight) / (newState.middleItemCount + newState.viewportItemCount);
+        if (correctedAvg > newState.avgRowHeight)
         {
-            // avgRowHeight should be corrected
-            newState.avgRowHeight = (sum + newState.lastItemsTotalHeight) / (newState.middleItemCount + newState.viewportItemCount);
+            newState.avgRowHeight = correctedAvg;
         }
     }
     return newState;