d6_path_redirect has to define the *correct* source_module annotation

I'd comment at #2947642: d6_path_redirect plugin must define the source_module property but that's now closed and since I'm not a maintainer, I can't reopen it.

The bug reported there was for D7. The patch committed added the same annotation to the sources for both the d7 and d6 migrations.

However, there was no "redirect" module for D6. The d6 annotation is wrong. It should say that the "source_module" is "path_redirect", since that's what the module was called.

I thought #2908282: Throw exception for source plugins without a source_module property and friends were supposed to throw helpful exceptions if a migration source had the wrong thing, and would warn you that the module you're looking for wasn't installed in the source DB. Nope. It all silently ignores the migration, now that the annotation is defined, but pointing to the wrong module.

When trying to migrate from D6 using 8.x-1.1 of redirect, drush ms never finds the migration.

dww@iskra% drush ms d6_path_redirect
dww@iskra%

With the following trivial patch to fix this:

index 973b3a7..3ffd4b6 100644
--- a/src/Plugin/migrate/source/PathRedirect.php
+++ b/src/Plugin/migrate/source/PathRedirect.php
@@ -9,7 +9,7 @@ use Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase;
  *
  * @MigrateSource(
  *   id = "d6_path_redirect",
- *   source_module = "redirect"
+ *   source_module = "path_redirect"
  * )
  */
 class PathRedirect extends DrupalSqlBase {

Now, drush finds the migration:

dww@iskra% drush ms d6_path_redirect
 Group: Default (default)  Status  Total  Imported  Unprocessed  Last imported
 d6_path_redirect          Idle    2475   0         2475

And happily runs it:

dww@iskra% drush mim d6_path_redirect
Processed 2475 items (2475 created, 0 updated, 0 failed, 0 ignored) - done with 'd6_path_redirect'

I'll attach the patch in a follow-up comment once I have a nid for this issue. Stay tuned.