Fix an infinite loop when tapping an unjoined room alias. (#6522)

* Fix a crash in universal link handling.
* Fix an infinite loop when tapping an unjoined room alias.

Riot/Modules/Application/LegacyAppDelegate.h

@@ -234,10 +234,10 @@ UINavigationControllerDelegate
  Process the fragment part of a vector.im link.
 
  @param fragment the fragment part of the universal link.
- @param universalLinkURL the unprocessed the universal link URL (optional).
+ @param universalLink the original universal link.
  @return YES in case of processing success.
  */
-- (BOOL)handleUniversalLinkFragment:(NSString*)fragment fromURL:(NSURL*)universalLinkURL;
+- (BOOL)handleUniversalLinkFragment:(NSString*)fragment fromLink:(UniversalLink*)universalLink;
 
 /**
  Process the URL of a vector.im link.

Riot/Modules/Application/LegacyAppDelegate.m

@@ -1242,7 +1242,7 @@ - (BOOL)handleUniversalLink:(NSUserActivity*)userActivity
  // Continue the registration with the passed nextLink
  MXLogDebug(@"[AppDelegate] handleUniversalLink. Complete registration with nextLink");
  NSURL *nextLink = [NSURL URLWithString:queryParams[@"nextLink"]];
- [self handleUniversalLinkFragment:nextLink.fragment fromURL:nextLink];
+ [self handleUniversalLinkURL:nextLink];
  }
  else
  {
@@ -1295,8 +1295,6 @@ - (BOOL)handleUniversalLinkWithParameters:(UniversalLinkParameters*)universalLin
  BOOL continueUserActivity = NO;
  MXKAccountManager *accountManager = [MXKAccountManager sharedManager];
 
- MXLogDebug(@"[AppDelegate] Universal link: handleUniversalLinkFragment: %@", fragment);
-
  // Make sure we have plain utf8 character for separators
  fragment = [fragment stringByRemovingPercentEncoding];
  MXLogDebug(@"[AppDelegate] Universal link: handleUniversalLinkFragment: %@", fragment);
@@ -1312,17 +1310,8 @@ - (BOOL)handleUniversalLinkWithParameters:(UniversalLinkParameters*)universalLin
  // Sanity check
  if (!pathParams.count)
  {
- // Handle simple room links with aliases/identifiers as UniversalLink will not parse these.
- NSString* absoluteUrl = [universalLink.url.absoluteString stringByRemovingPercentEncoding];
- if ([MXTools isMatrixRoomAlias:absoluteUrl]
- || [MXTools isMatrixRoomIdentifier:absoluteUrl])
- {
- pathParams = @[absoluteUrl];
- }
- else {
- MXLogDebug(@"[AppDelegate] Universal link: Error: No path parameters");
- return NO;
- }
+ MXLogFailure(@"[AppDelegate] Universal link: Error: No path parameters");
+ return NO;
  }
 
  NSString *roomIdOrAlias;
@@ -1498,9 +1487,11 @@ - (BOOL)handleUniversalLinkWithParameters:(UniversalLinkParameters*)universalLin
  if (newFragment && ![newFragment isEqualToString:fragment])
  {
  self->universalLinkFragmentPendingRoomAlias = @{resolution.roomId: roomIdOrAlias};
-
+
+ // Create a new link with the updated fragment, otherwise we loop back round resolving the room ID infinitely.
+ UniversalLink *newLink = [[UniversalLink alloc] initWithUrl:universalLink.url updatedFragment:newFragment];
  UniversalLinkParameters *newParameters = [[UniversalLinkParameters alloc] initWithFragment:newFragment
- universalLink:universalLink
+ universalLink:newLink
  presentationParameters:presentationParameters];
  [self handleUniversalLinkWithParameters:newParameters];
  }
@@ -1704,8 +1695,9 @@ - (BOOL)handleUniversalLinkURL:(NSURL*)universalLinkURL
 {
  // iOS Patch: fix vector.im urls before using it
  NSURL *fixedURL = [Tools fixURLWithSeveralHashKeys:universalLinkURL];
+ UniversalLink *link = [[UniversalLink alloc] initWithUrl:universalLinkURL];
 
- return [self handleUniversalLinkFragment:fixedURL.fragment fromURL:universalLinkURL];
+ return [self handleUniversalLinkFragment:fixedURL.fragment fromLink:link];
 }
 
 - (void)resetPendingUniversalLink

Riot/Modules/Common/Recents/RecentsViewController.m

@@ -1602,10 +1602,10 @@ - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath
 
  if (roomIdOrAlias.length)
  {
- // Open the room or preview it
- NSString *fragment = [NSString stringWithFormat:@"/room/%@", [MXTools encodeURIComponent:roomIdOrAlias]];
- NSURL *url = [NSURL URLWithString:[MXTools permalinkToRoom:fragment]];
- [[AppDelegate theDelegate] handleUniversalLinkFragment:fragment fromURL:url];
+ // Create a permalink to open or preview the room.
+ NSString *permalink = [MXTools permalinkToRoom:roomIdOrAlias];
+ NSURL *permalinkURL = [NSURL URLWithString:permalink];
+ [[AppDelegate theDelegate] handleUniversalLinkURL:permalinkURL];
  }
  [tableView deselectRowAtIndexPath:indexPath animated:NO];
  }

Riot/Modules/Communities/Home/GroupHomeViewController.m

@@ -892,7 +892,8 @@ - (BOOL)textView:(UITextView *)textView shouldInteractWithURL:(NSURL *)URL inRan
  // Open the group or preview it
  NSString *fragment = [NSString stringWithFormat:@"/group/%@",
  [MXTools encodeURIComponent:absoluteURLString]];
- [[AppDelegate theDelegate] handleUniversalLinkFragment:fragment fromURL:URL];
+ UniversalLink *link = [[UniversalLink alloc] initWithUrl:URL];
+ [[AppDelegate theDelegate] handleUniversalLinkFragment:fragment fromLink:link];
  }
 
  return shouldInteractWithURL;

Riot/Modules/Room/RoomViewController.m

@@ -4279,10 +4279,11 @@ - (BOOL)dataSource:(MXKDataSource *)dataSource shouldDoAction:(NSString *)action
 
  NSString *roomIdOrAlias = absoluteURLString;
 
- // Open the room or preview it
- NSString *fragment = [NSString stringWithFormat:@"/room/%@", [MXTools encodeURIComponent:roomIdOrAlias]];
+ // Create a permalink to open or preview the room.
+ NSString *permalink = [MXTools permalinkToRoom:roomIdOrAlias];
+ NSURL *permalinkURL = [NSURL URLWithString:permalink];
 
- [self handleUniversalLinkFragment:fragment fromURL:url];
+ [self handleUniversalLinkURL:permalinkURL];
  }
  // Preview the clicked group
  else if ([MXTools isMatrixGroupIdentifier:absoluteURLString])

Riot/Utils/UniversalLink.h

@@ -40,6 +40,11 @@ NS_ASSUME_NONNULL_BEGIN
 /// @param url original url
 - (id)initWithUrl:(NSURL *)url;
 
+/// An Initializer that preserves the original URL, but parses the parameters from an updated fragment.
+/// @param url original url
+/// @param fragment the updated fragment to parse.
+- (id)initWithUrl:(NSURL *)url updatedFragment:(NSString *)fragment;
+
 @end
 
 NS_ASSUME_NONNULL_END

Riot/Utils/UniversalLink.m

@@ -27,7 +27,22 @@ - (id)initWithUrl:(NSURL *)url
  _url = url;
 
  // Extract required parameters from the link
- [self parsePathAndQueryParams];
+ [self parsePathAndQueryParamsForURL:url];
+ }
+ return self;
+}
+
+- (id)initWithUrl:(NSURL *)url updatedFragment:(NSString *)fragment
+{
+ self = [super init];
+ if (self)
+ {
+ _url = url;
+
+ // Update the url with the fragment
+ NSURLComponents *components = [[NSURLComponents alloc] initWithURL:url resolvingAgainstBaseURL:NO];
+ components.fragment = fragment;
+ [self parsePathAndQueryParamsForURL:components.URL];
  }
  return self;
 }
@@ -38,12 +53,12 @@ Extract params from the URL fragment part (after '#') of a vector.im Universal l
  The fragment can contain a '?'. So there are two kinds of parameters: path params and query params.
  It is in the form of /[pathParam1]/[pathParam2]?[queryParam1Key]=[queryParam1Value]&[queryParam2Key]=[queryParam2Value]
  */
-- (void)parsePathAndQueryParams
+- (void)parsePathAndQueryParamsForURL:(NSURL *)url
 {
  NSArray<NSString*> *pathParams;
  NSMutableDictionary *queryParams = [NSMutableDictionary dictionary];
 
- NSArray<NSString*> *fragments = [_url.fragment componentsSeparatedByString:@"?"];
+ NSArray<NSString*> *fragments = [url.fragment componentsSeparatedByString:@"?"];
 
  // Extract path params
  pathParams = [[fragments[0] stringByRemovingPercentEncoding] componentsSeparatedByString:@"/"];
@@ -57,7 +72,7 @@ - (void)parsePathAndQueryParams
  }];
 
  // Extract query params
- NSURLComponents *components = [NSURLComponents componentsWithURL:_url resolvingAgainstBaseURL:NO];
+ NSURLComponents *components = [NSURLComponents componentsWithURL:url resolvingAgainstBaseURL:NO];
  for (NSURLQueryItem *item in components.queryItems)
  {
  if (item.value)

changelog.d/6492.bugfix

@@ -0,0 +1 @@
+Universal Links: Fix an infinite loop when handling a universal link for an unjoined room (or in some cases a crash).