Temporary accounts: Perform redirect for first successful edit

Why:

- We want to make sure that the top-level redirect fires for temporary
  accounts which were created in an edit attempt, but did not yet save
  an edit

What:

- In EditPage and ApiEditPage, perform the redirect if there is a saved
  temp user as part of the current process, or if the user account is a
  temporary one and it has no edits. Note that this means the top-level
  redirect would be performed if a temp user creates a first edit on a
  non-home wiki:
   - logged out user makes a failed attempt on wiki A, temp account is
     created
   - same user makes a successful edit on wiki A, redirect hook fires
   - same user visits wiki B and makes a succesful edit, redirect hook
     fires

Note:

- We could consider setting a query parameter like
  `createdinrequest=1` to signal to TempUserCreatedRedirect
  implementations that the temporary account was created in the current
  request, and did not exist earlier. But I am not sure if we have a use
  case for needing that, so have left it out of this patch.

Bug: T359405
Change-Id: If4b8c561383f993606c0ba565591871195a1f8c2

1 files changed, 12 insertions, 2 deletions

diff --git a/includes/api/ApiEditPage.php b/includes/api/ApiEditPage.php
index 14203f935726..52ded5688b8d 100644
--- a/includes/api/ApiEditPage.php
+++ b/includes/api/ApiEditPage.php
@@ -607,12 +607,22 @@ class ApiEditPage extends ApiBase {
 				}
 				$this->persistGlobalSession();
 
-				if ( isset( $result['savedTempUser'] ) ) {
+				// If the temporary account was created in this request,
+				// or if the temporary account has zero edits (implying
+				// that the account was created during a failed edit
+				// attempt in a previous request), perform the top-level
+				// redirect to ensure the account is attached.
+				// Note that the temp user could already have performed
+				// the top-level redirect if this a first edit on
+				// a wiki that is not the user's home wiki.
+				$shouldRedirectForTempUser = isset( $result['savedTempUser'] ) ||
+					$user->isTemp() && $user->getEditCount() === 0;
+				if ( $shouldRedirectForTempUser ) {
 					$r['tempusercreated'] = true;
 					$params['returnto'] ??= $titleObj->getPrefixedDBkey();
 					$redirectUrl = $this->getTempUserRedirectUrl(
 						$params,
-						$result['savedTempUser']
+						$result['savedTempUser'] ?? $user
 					);
 					if ( $redirectUrl ) {
 						$r['tempusercreatedredirect'] = $redirectUrl;