[do not merge] Temporary keyPath fixes

Found some keyPath bugs. Seb is fixing one of them in another PR. Patching them
here to unblock testing the fixture.

Author: acdlite

packages/react-server/src/ReactFizzServer.js

@@ -218,6 +218,7 @@ export type Task = {
   blockedSegment: Segment, // the segment we'll write to
   abortSet: Set<Task>, // the abortable set that this task belongs to
   keyPath: Root | KeyNode, // the path of all parent keys currently rendering
+  index: number,
   formatContext: FormatContext, // the format's specific context (e.g. HTML/SVG/MathML)
   legacyContext: LegacyContext, // the current legacy context that this task is executing in
   context: ContextSnapshot, // the current new context that this task is executing in
@@ -388,6 +389,7 @@ export function createRequest(
     rootSegment,
     abortSet,
     null,
+    0,
     rootFormatContext,
     emptyContextObject,
     rootContextSnapshot,
@@ -489,6 +491,7 @@ export function resumeRequest(
     rootSegment,
     abortSet,
     null,
+    0,
     postponedState.rootFormatContext,
     emptyContextObject,
     rootContextSnapshot,
@@ -546,6 +549,7 @@ function createTask(
   blockedSegment: Segment,
   abortSet: Set<Task>,
   keyPath: Root | KeyNode,
+  index: number,
   formatContext: FormatContext,
   legacyContext: LegacyContext,
   context: ContextSnapshot,
@@ -564,6 +568,7 @@ function createTask(
     blockedSegment,
     abortSet,
     keyPath,
+    index,
     formatContext,
     legacyContext,
     context,
@@ -845,6 +850,7 @@ function renderSuspenseBoundary(
     boundarySegment,
     fallbackAbortSet,
     task.keyPath,
+    1,
     task.formatContext,
     task.legacyContext,
     task.context,
@@ -968,7 +974,7 @@ function finishClassComponent(
         childContextTypes,
       );
       task.legacyContext = mergedContext;
-      renderNodeDestructive(request, task, null, nextChildren, 0);
+      renderNode(request, task, nextChildren, 0);
       task.legacyContext = previousContext;
       return;
     }
@@ -1907,6 +1913,7 @@ function injectPostponedHole(
 function spawnNewSuspendedTask(
   request: Request,
   task: Task,
+  childIndex: number,
   thenableState: ThenableState | null,
   x: Wakeable,
 ): void {
@@ -1934,6 +1941,7 @@ function spawnNewSuspendedTask(
     newSegment,
     task.abortSet,
     task.keyPath,
+    childIndex,
     task.formatContext,
     task.legacyContext,
     task.context,
@@ -1998,17 +2006,24 @@ function renderNode(
     if (typeof x === 'object' && x !== null) {
       // $FlowFixMe[method-unbinding]
       if (typeof x.then === 'function') {
-        const wakeable: Wakeable = (x: any);
-        const thenableState = getThenableStateAfterSuspending();
-        spawnNewSuspendedTask(request, task, thenableState, wakeable);
-
         // Restore the context. We assume that this will be restored by the inner
         // functions in case nothing throws so we don't use "finally" here.
         task.formatContext = previousFormatContext;
         task.legacyContext = previousLegacyContext;
         task.context = previousContext;
         task.keyPath = previousKeyPath;
         task.treeContext = previousTreeContext;
+
+        const wakeable: Wakeable = (x: any);
+        const thenableState = getThenableStateAfterSuspending();
+        spawnNewSuspendedTask(
+          request,
+          task,
+          childIndex,
+          thenableState,
+          wakeable,
+        );
+
         // Restore all active ReactContexts to what they were before.
         switchContext(previousContext);
         if (__DEV__) {
@@ -2336,7 +2351,13 @@ function retryTask(request: Request, task: Task): void {
     const prevThenableState = task.thenableState;
     task.thenableState = null;
 
-    renderNodeDestructive(request, task, prevThenableState, task.node, 0);
+    renderNodeDestructive(
+      request,
+      task,
+      prevThenableState,
+      task.node,
+      task.index,
+    );
     pushSegmentFinale(
       segment.chunks,
       request.renderState,