fail quietly when search messagelookup gets dropped

ts/components/conversationList/MessageSearchResult.tsx

@@ -95,6 +95,7 @@ export const MessageSearchResult: FunctionComponent<PropsType> = React.memo(
     }, [showConversation, conversationId, id]);
 
     if (!from || !to) {
+      // Note: mapStateToProps() may return null if the message is not found.
       return <div />;
     }
 

ts/state/ducks/search.ts

@@ -37,6 +37,7 @@ import {
   TARGETED_CONVERSATION_CHANGED,
 } from './conversations';
 import { removeDiacritics } from '../../util/removeDiacritics';
+import * as log from '../../logging/log';
 
 const {
   searchMessages: dataSearchMessages,
@@ -344,6 +345,7 @@ export function reducer(
   action: Readonly<SearchActionType>
 ): SearchStateType {
   if (action.type === 'SHOW_ARCHIVED_CONVERSATIONS') {
+    log.info('search: show archived conversations, clearing message lookup');
     return getEmptyState();
   }
 
@@ -357,6 +359,8 @@ export function reducer(
   }
 
   if (action.type === 'SEARCH_CLEAR') {
+    log.info('search: cleared, clearing message lookup');
+
     return {
       ...getEmptyState(),
       startSearchCounter: state.startSearchCounter,
@@ -397,6 +401,8 @@ export function reducer(
       };
     }
 
+    log.info('search: searching in new conversation, clearing message lookup');
+
     return {
       ...getEmptyState(),
       searchConversationId,
@@ -406,6 +412,8 @@ export function reducer(
   if (action.type === 'CLEAR_CONVERSATION_SEARCH') {
     const { searchConversationId } = state;
 
+    log.info('search: cleared conversation search, clearing message lookup');
+
     return {
       ...getEmptyState(),
       searchConversationId,
@@ -418,9 +426,12 @@ export function reducer(
 
     // Reject if the associated query is not the most recent user-provided query
     if (state.query !== query) {
+      log.info('search: query mismatch, ignoring message results');
       return state;
     }
 
+    log.info('search: got new messages, updating message lookup');
+
     const messageIds = messages.map(message => message.id);
 
     return {
@@ -438,6 +449,7 @@ export function reducer(
 
     // Reject if the associated query is not the most recent user-provided query
     if (state.query !== query) {
+      log.info('search: query mismatch, ignoring message results');
       return state;
     }
 
@@ -459,6 +471,9 @@ export function reducer(
     const { searchConversationId } = state;
 
     if (searchConversationId && searchConversationId !== conversationId) {
+      log.info(
+        'search: targeted conversation changed, clearing message lookup'
+      );
       return getEmptyState();
     }
 
@@ -474,6 +489,9 @@ export function reducer(
     const { searchConversationId } = state;
 
     if (searchConversationId && searchConversationId === conversationId) {
+      log.info(
+        'search: searched conversation unloaded, clearing message lookup'
+      );
       return getEmptyState();
     }
 
@@ -489,6 +507,8 @@ export function reducer(
     const { payload } = action;
     const { id } = payload;
 
+    log.info('search: message deleted, removing from message lookup');
+
     return {
       ...state,
       messageIds: reject(messageIds, messageId => id === messageId),

ts/state/smart/MessageSearchResult.tsx

@@ -11,6 +11,7 @@ import { MessageSearchResult } from '../../components/conversationList/MessageSe
 import { getPreferredBadgeSelector } from '../selectors/badges';
 import { getIntl, getTheme } from '../selectors/user';
 import { getMessageSearchResultSelector } from '../selectors/search';
+import * as log from '../../logging/log';
 
 type SmartProps = {
   id: string;
@@ -22,7 +23,8 @@ function mapStateToProps(state: StateType, ourProps: SmartProps) {
 
   const props = getMessageSearchResultSelector(state)(id);
   if (!props) {
-    throw new Error('SmartMessageSearchResult: no message was found');
+    log.error('SmartMessageSearchResult: no message was found');
+    return null;
   }
 
   return {