Applied facebook#15670 - contentOffset validation

facebook#15670

Author: nixoz

React/Views/RCTScrollView.m

@@ -314,11 +314,16 @@ - (void)setFrame:(CGRect)frame
     contentSize.width + contentInset.left + contentInset.right,
     contentSize.height + contentInset.top + contentInset.bottom);
 
-  CGSize boundsSize = self.bounds.size;
-
-  self.contentOffset = CGPointMake(
-    MAX(0, MIN(originalOffset.x, fullContentSize.width - boundsSize.width)),
-    MAX(0, MIN(originalOffset.y, fullContentSize.height - boundsSize.height)));
+  // If contentSize has not been measured yet we can't check bounds.
+  if (CGSizeEqualToSize(contentSize, CGSizeZero)) {
+    self.contentOffset = originalOffset;
+  } else {
+    // Make sure offset don't exceed bounds. This could happen on screen rotation.
+    CGSize boundsSize = self.bounds.size;
+    self.contentOffset = CGPointMake(
+      MAX(-contentInset.left, MIN(contentSize.width - boundsSize.width + contentInset.right, originalOffset.x)),
+      MAX(-contentInset.top, MIN(contentSize.height - boundsSize.height + contentInset.bottom, originalOffset.y)));
+  }
 }
 
 #if !TARGET_OS_TV