diff --git a/src/diff/children.js b/src/diff/children.js index d80a5fd384..57bbe89113 100644 --- a/src/diff/children.js +++ b/src/diff/children.js @@ -227,52 +227,24 @@ function constructNewChildrenArray(newParentVNode, renderResult, oldChildren) { childVNode = newParentVNode._children[i] = childVNode; } - const skewedIndex = i + skew; - // Handle unmounting null placeholders, i.e. VNode => null in unkeyed children if (childVNode == null) { - oldVNode = oldChildren[skewedIndex]; - if ( - oldVNode && - oldVNode.key == null && - oldVNode._dom && - (oldVNode._flags & MATCHED) === 0 - ) { - if (oldVNode._dom == newParentVNode._nextDom) { - newParentVNode._nextDom = getDomSibling(oldVNode); - } - - unmount(oldVNode, oldVNode, false); - - // Explicitly nullify this position in oldChildren instead of just - // setting `_match=true` to prevent other routines (e.g. - // `findMatchingIndex` or `getDomSibling`) from thinking VNodes or DOM - // nodes in this position are still available to be used in diffing when - // they have actually already been unmounted. For example, by only - // setting `_match=true` here, the unmounting loop later would attempt - // to unmount this VNode again seeing `_match==true`. Further, - // getDomSibling doesn't know about _match and so would incorrectly - // assume DOM nodes in this subtree are mounted and usable. - oldChildren[skewedIndex] = null; - remainingOldChildren--; - } continue; } + const skewedIndex = i + skew; childVNode._parent = newParentVNode; childVNode._depth = newParentVNode._depth + 1; - const matchingIndex = findMatchingIndex( + // Temporarily store the matchingIndex on the _index property so we can pull + // out the oldVNode in diffChildren. We'll override this to the VNode's + // final index after using this property to get the oldVNode + const matchingIndex = (childVNode._index = findMatchingIndex( childVNode, oldChildren, skewedIndex, remainingOldChildren - ); - - // Temporarily store the matchingIndex on the _index property so we can pull - // out the oldVNode in diffChildren. We'll override this to the VNode's - // final index after using this property to get the oldVNode - childVNode._index = matchingIndex; + )); oldVNode = null; if (matchingIndex !== -1) { @@ -318,16 +290,18 @@ function constructNewChildrenArray(newParentVNode, renderResult, oldChildren) { skew--; } else if (matchingIndex == skewedIndex + 1) { skew++; - } else if (matchingIndex > skewedIndex) { - skew--; } else { - skew++; - } + if (matchingIndex > skewedIndex) { + skew--; + } else { + skew++; + } - // Move this VNode's DOM if the original index (matchingIndex) doesn't - // match the new skew index (i + new skew) - if (matchingIndex !== i + skew) { - childVNode._flags |= INSERT_VNODE; + // Move this VNode's DOM if the original index (matchingIndex) doesn't + // match the new skew index (i + new skew) + if (matchingIndex !== i + skew) { + childVNode._flags |= INSERT_VNODE; + } } } }