The participants picker is sorted by the name it shows (#1706)

QA on [central-ticketing] #1598, reading the dropdown back after the
picker became chips: typing `an` listed "Toews, Fast, Ivanov, Mwangi,
Bergman, Anderson" — to an operator, no order at all.

It was in fact perfectly ordered. `searchUsers()` came out of #1598's
chip conversion with `->orderBy('name')`, and `users.name` is the cached
"First Last" ("Abigail Toews", "Andrew Fast", "Avery Ivanov") — the one
string a chip row no longer prints. A list labelled "Last, First" and
collated by "First Last" reads as unsorted, which is #524's own reported
defect; the sibling conversion on [central-staff-employment] #1597 names
it as the thing it had to fix at the same moment.

So the collation moves with the label: `PersonNames::orderUsers()`, the
platform's single answer, which the reference search
(`admin.settings.users.search`) and the other chipped pickers already
use, and which honours the operator's `name_format` rather than assuming
surname-first.

Not cosmetic: the sort runs before `limit(10)`, so on a common surname
the two collations offer a different set of people, not the same set
shuffled.

Three tests in the shell suite (TicketParticipantsAreChipsTest) — the
collation, the `name_format` setting, and which ten survive the limit.
The first and third are red against `orderBy('name')`.

database/migrations/2026_09_04_000001_repair_inconsistent_merged_tickets.php

@@ -0,0 +1,73 @@
+<?php
+
+use Dashboard\Ticketing\Support\MergedTicketRepair;
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Support\Facades\Log;
+
+/**
+ * OPTION A OF [central-ticketing] #938 — the repair, behind a setting that is OFF.
+ *
+ * The rows the merge bug minted (`merged_into_id` set, `status` back to `open`)
+ * are data, not code, and #920 deliberately shipped no data change. This
+ * migration is the one that would: it re-marks every such row `merged`, which
+ * makes it read-only under #920's guard, and it leaves every message,
+ * participant and field edit made after the merge exactly where it is.
+ *
+ * IT DOES NOT RUN UNLESS THE OPERATOR HAS ASKED. `MergedTicketRepair::SETTING`
+ * — "auto-repair inconsistent merged tickets on deploy" — defaults off, and a
+ * box that has never heard of it therefore deploys this migration and changes
+ * nothing at all. That is what lets the code ship ahead of the decision: the
+ * office gets the badge and the one-click fix now (option B), and turning this
+ * on is the operator's separate, later, reversible act (option C).
+ *
+ * WHAT IT ALWAYS DOES, EITHER WAY, IS COUNT AND SAY SO. The dry-run count goes
+ * to the log on every deploy whether the repair is armed or not, because the
+ * number is the thing #938 was blocked on and a deploy is the one moment
+ * something is definitely looking at prod's database.
+ */
+return new class extends Migration
+{
+    public function up(): void
+    {
+        // The dry run, first and unconditionally.
+        $count = MergedTicketRepair::count();
+
+        Log::info(sprintf(
+            '[ticketing] #938 dry run: %d ticket(s) have merged_into_id set with a status other than "merged".',
+            $count,
+        ));
+
+        if ($count === 0) {
+            return;
+        }
+
+        if (! MergedTicketRepair::enabledOnDeploy()) {
+            Log::info(sprintf(
+                '[ticketing] #938: leaving those %d row(s) editable — "%s" is off. '
+                .'Turn it on in Ticketing → Settings → Automation, or fix them one at a '
+                .'time with the "Mark merged" button on each ticket.',
+                $count,
+                MergedTicketRepair::SETTING,
+            ));
+
+            return;
+        }
+
+        MergedTicketRepair::repairAll('migration 2026_09_04_000001');
+    }
+
+    /**
+     * There is no down migration, and that is a decision rather than an omission.
+     *
+     * Reverting would mean putting each row's status back to what it was before
+     * the bad save, and nothing anywhere records what that was — the bug
+     * overwrote it. Setting them all back to `open` would not be a rollback; it
+     * would be re-creating the corrupt shape on rows that may have been merged
+     * legitimately years ago. A row repaired in error is corrected the same way
+     * any other status is: an agent edits the ticket.
+     */
+    public function down(): void
+    {
+        // Intentionally empty — see the note above.
+    }
+};

src/Console/Commands/RepairMergedTickets.php

@@ -0,0 +1,67 @@
+<?php
+
+namespace Dashboard\Ticketing\Console\Commands;
+
+use Dashboard\Ticketing\Support\MergedTicketRepair;
+use Illuminate\Console\Command;
+
+/**
+ * THE DRY-RUN COUNT, AND THE REPAIR — [central-ticketing] #938.
+ *
+ * The first question #938 asks is a number: how many rows on prod carry
+ * `merged_into_id` with a status other than `merged`. That number decides
+ * whether the office corrects them one at a time from the badge or whether a
+ * deploy re-marks them all, and there was no way to ask for it that did not
+ * involve typing a raw UPDATE-shaped statement into tinker on the production
+ * box. So `--dry-run` is the default and is the point of this command:
+ *
+ *     php artisan ticketing:repair-merged --dry-run    # count + list, writes NOTHING
+ *     php artisan ticketing:repair-merged --force      # re-mark them all
+ *
+ * `--force` is required to write, rather than `--dry-run` being required not
+ * to. A repair command whose bare form repairs is one fat-finger away from
+ * being the incident it was written to clean up after.
+ */
+class RepairMergedTickets extends Command
+{
+    protected $signature = 'ticketing:repair-merged
+                            {--dry-run : Count and list the inconsistent rows; write nothing (the default).}
+                            {--force : Actually re-mark every inconsistent row as merged.}';
+
+    protected $description = 'Report — or, with --force, repair — tickets whose merged_into_id is set while their status is not "merged" (#938).';
+
+    public function handle(): int
+    {
+        $rows = MergedTicketRepair::rows();
+
+        $this->line(sprintf(
+            'SELECT COUNT(*) FROM tickets WHERE merged_into_id IS NOT NULL AND status <> \'merged\' => %d',
+            $rows->count(),
+        ));
+
+        if ($rows->isEmpty()) {
+            $this->info('Nothing is inconsistent. No repair to make.');
+
+            return 0;
+        }
+
+        $this->table(
+            ['id', 'number', 'status', 'merged_into_id', 'updated_at'],
+            $rows->map(fn ($t) => [
+                $t->id, $t->number, $t->status, $t->merged_into_id, (string) $t->updated_at,
+            ])->all(),
+        );
+
+        if (! $this->option('force')) {
+            $this->comment('Dry run — nothing was written. Re-run with --force to re-mark these as merged.');
+
+            return 0;
+        }
+
+        $changed = MergedTicketRepair::repairAll('artisan ticketing:repair-merged');
+
+        $this->info("Re-marked {$changed} ticket(s) as merged. Their messages and participants are untouched.");
+
+        return 0;
+    }
+}

src/Http/Controllers/TicketAttachmentController.php

@@ -29,6 +29,11 @@ class TicketAttachmentController extends Controller
             abort(403);
         }
 
+        // Same read-only rule as a reply — see TicketMessageController::store(). #920
+        if ($ticket->isMerged()) {
+            return back()->withErrors(['ticket' => Ticket::READ_ONLY_REASON]);
+        }
+
         $request->validate([
             'file' => 'required|file|max:' . (self::MAX_SIZE_MB * 1024),
             // Bug #5: message_id must belong to THIS ticket, not any arbitrary message

src/Http/Controllers/TicketController.php

@@ -3,6 +3,9 @@
 namespace Dashboard\Ticketing\Http\Controllers;
 
 use App\Models\Setting;
+use App\Models\User;
+use App\Support\PersonChip;
+use App\Support\PersonNames;
 use Dashboard\Ticketing\Models\PriorityLevel;
 use Dashboard\Ticketing\Models\Ticket;
 use Dashboard\Ticketing\Models\TicketAttachment;
@@ -13,6 +16,8 @@ use Dashboard\Ticketing\Models\TicketMessage;
 use Dashboard\Ticketing\Models\TicketParticipant;
 use Dashboard\Ticketing\Models\TicketStatus;
 use Dashboard\Ticketing\Models\TicketView;
+use Dashboard\Ticketing\Support\MergedTicketRepair;
+use Dashboard\Ticketing\Support\StrandedMerge;
 use Illuminate\Http\Request;
 use Illuminate\Routing\Controller;
 use Illuminate\Support\Facades\Auth;
@@ -23,6 +28,13 @@ use Inertia\Response;
 
 class TicketController extends Controller
 {
+    /**
+     * The sidebar's views, and the only values `?filter=` means anything as.
+     * Index.vue's `visibleViews` draws exactly these; `savePrefs()` validates
+     * against them; `index()` normalises anything else to `all` (#1054).
+     */
+    private const VIEW_FILTERS = ['all', 'mine', 'unassigned', 'pending', 'resolved', 'merged'];
+
     private function agentGroupIds(): array
     {
         return TicketingAgentAccess::where('user_id', Auth::id())
@@ -47,6 +59,40 @@ class TicketController extends Controller
             ->exists();
     }
 
+    /**
+     * REFUSE A WRITE TO A MERGED TICKET — [central-ticketing] #920.
+     *
+     * The Show page has always announced "This ticket has been merged and is
+     * read-only." and hidden the reply composer and the Merge button. Nothing
+     * enforced it: the Edit form was still linked, still rendered (with its Status
+     * select blank, because `merged` is not one of its options), and `update()`
+     * happily wrote `status = open` while leaving `merged_into_id` pointing at the
+     * target. That produced a ticket that was live and assignable in the All Open
+     * queue and simultaneously merged into another one, with none of its own
+     * messages — an empty duplicate of the ticket it had been folded into.
+     *
+     * So the check lives HERE, on the server, once, and every write path that the
+     * page presents as unavailable calls it. Returning a refusal rather than
+     * `abort(403)` on purpose: the realistic way to arrive here is a page that was
+     * already open when somebody else merged the ticket, and that operator is
+     * better served by the reason on the ticket than by an error screen.
+     * `FormErrors` renders any key it is handed, so the sentence shows up.
+     *
+     * @return \Illuminate\Http\RedirectResponse|null  null when the write may proceed
+     */
+    private function refuseIfMerged(Ticket $ticket, bool $stayPut = false)
+    {
+        if (! $ticket->isMerged()) {
+            return null;
+        }
+
+        $errors = ['ticket' => Ticket::READ_ONLY_REASON];
+
+        return $stayPut
+            ? back()->withErrors($errors)
+            : redirect()->route('ticketing.show', $ticket)->withErrors($errors);
+    }
+
     /**
      * Filter messages for submitters — strip internal notes.
      */
@@ -77,6 +123,18 @@ class TicketController extends Controller
             $request->merge(['filter' => $pref['filter']]);
         }
 
+        // #1054 — a `filter` the sidebar has no view for used to fall through to
+        // the All Open branch and then be echoed straight back in `props.filters`,
+        // so `?filter=closed` looked like a real view that just happened to be
+        // showing open tickets. There is no Closed view anywhere in the UI;
+        // anything unrecognised is All Open, and now says so. The list is the
+        // one `savePrefs()` validates against and the one Index.vue draws.
+        // Only rewrites a filter that was actually asked for: an absent one keeps
+        // meaning "no view chosen", which is what leaves `filter` out of the URL.
+        if ($request->filled('filter') && ! in_array($request->filter, self::VIEW_FILTERS, true)) {
+            $request->merge(['filter' => 'all']);
+        }
+
         // If no groups exist at all, render a first-run / bootstrap state
         $totalGroups = TicketingGroup::count();
         if ($totalGroups === 0) {
@@ -113,6 +171,13 @@ class TicketController extends Controller
                 'unassigned' => (clone $baseQuery)->whereNull('assigned_to')->whereNotIn('status', $closedSlugs)->count(),
                 'pending' => (clone $baseQuery)->where('status', 'pending')->count(),
                 'resolved' => (clone $baseQuery)->whereIn('status', $closedSlugs)->count(),
+                // #938: the pointer, not the status — this view exists to show the
+                // rows where the two disagree, so filtering by `status = merged`
+                // would hide exactly the ones worth looking at. #1567: nor is the
+                // pointer alone enough, because a stranded row has neither a
+                // target nor a disagreeing status. Either mark of a merge counts.
+                'merged' => (clone $baseQuery)->everMerged()->count(),
+                'merged_inconsistent' => (clone $baseQuery)->mergeInconsistent()->count(),
             ]
             : [
                 'all' => (clone $baseQuery)->count(),
@@ -120,6 +185,8 @@ class TicketController extends Controller
                 'unassigned' => 0,
                 'pending' => (clone $baseQuery)->where('status', 'pending')->count(),
                 'resolved' => (clone $baseQuery)->whereIn('status', $closedSlugs)->count(),
+                'merged' => 0,
+                'merged_inconsistent' => 0,
             ];
 
         $query = Ticket::with(['group', 'priority', 'project']);
@@ -139,14 +206,36 @@ class TicketController extends Controller
             if ($request->filled('project_id')) {
                 $query->where('project_id', $request->project_id);
             }
+            // #1054 — the work queues scope by `$closedSlugs`, the same list the
+            // counts above use. They used to spell it `['resolved', 'closed']`
+            // by hand, which predates the `merged` status: a correctly merged
+            // ticket stayed in Unassigned as pickable work while the sidebar
+            // count next to it — already reading `$closedSlugs` — excluded it,
+            // so the view disagreed with its own header (4 vs 5). Scoping by
+            // STATUS and not by `merged_into_id` is deliberate: #938's
+            // inconsistent rows (pointer set, status still open) are live work
+            // until somebody repairs them, and hiding them from the queue would
+            // hide the rows that most need a human.
             if ($request->filter === 'mine') {
-                $query->where('assigned_to', $user->id)->whereNotIn('status', ['resolved', 'closed']);
+                $query->where('assigned_to', $user->id)->whereNotIn('status', $closedSlugs);
             } elseif ($request->filter === 'unassigned') {
-                $query->whereNull('assigned_to')->whereNotIn('status', ['resolved', 'closed']);
+                $query->whereNull('assigned_to')->whereNotIn('status', $closedSlugs);
             } elseif ($request->filter === 'pending') {
                 $query->where('status', 'pending');
             } elseif ($request->filter === 'resolved') {
                 $query->whereIn('status', $closedSlugs);
+            } elseif ($request->filter === 'merged') {
+                // Every ticket that has been folded into another one, whatever its
+                // status says — which is what makes this the place the office
+                // finds the rows #938 is about. `merged` is a closed slug, so the
+                // whereNotIn below would drop the consistent half of the list.
+                //
+                // #1567 — and whatever its POINTER says, too. Scoping by the
+                // pointer alone dropped a ticket whose merge target had been
+                // deleted out of this view entirely (n went 1 → 0 on the delete),
+                // leaving it visible only under Resolved: the rows most in need of
+                // a human were the ones the view could not show.
+                $query->everMerged();
             } elseif (!$request->filled('status')) {
                 $query->whereNotIn('status', $closedSlugs);
             }
@@ -382,7 +471,39 @@ class TicketController extends Controller
             ->push($ticket->submitter_id)
             ->push($ticket->assigned_to)
             ->filter()->unique();
-        $users = DB::table('users')->whereIn('id', $userIds)->get(['id', 'name', 'email'])->keyBy('id');
+        /*
+         * EVERY PERSON ON THIS PAGE, IN THE PLATFORM'S ROW SHAPE (#1598).
+         *
+         * This was `DB::table('users')->get(['id', 'name', 'email'])`, and the
+         * Participants card it feeds drew each of those as
+         * `{{ p.user?.name || p.user?.email }}` — a bare text row where the rest
+         * of the platform draws a chip. `PersonChip::rows()` is the shared
+         * serializer, so what those rows SAY is the operator's chip setting
+         * rather than this method's select list, and it is the same payload the
+         * participant SEARCH answers with: the person picked and the row they
+         * were picked from cannot disagree about what they are called.
+         *
+         * `rows()` AND NOT THE MODEL. This map also feeds the message bylines
+         * and the assignee, so a `User` handed straight to Inertia would put
+         * every column of `users` — `preferred_pin`, `preferred_password`,
+         * `date_of_birth` — on the page for anybody who has ever replied to a
+         * ticket. `rows()` is exactly `{id, name, email, person}`, and `person`
+         * is the curated allow-list `PersonChip::FIELDS` describes.
+         *
+         * ONE BULK PASS for the whole page: `forMany()` inside `rows()` reads
+         * the alias catalogue and the school year once for the collection, and a
+         * chip built per row would repeat that for every participant, every
+         * message author and the assignee on a fifty-reply thread.
+         *
+         * `PersonChip::columns()` is the select list because a chip line may
+         * name ANY user column, and a constrained select hands the helper a
+         * model whose attribute is simply absent — which it cannot tell from a
+         * person who has no value, so the line goes blank for everybody with
+         * nothing failing.
+         */
+        $users = collect(PersonChip::rows(
+            User::whereIn('id', $userIds)->get(PersonChip::columns())
+        ))->keyBy('id');
 
         $visibleMessages->each(function ($msg) use ($users) {
             $msg->author = $msg->user_id ? ($users[$msg->user_id] ?? null) : null;
@@ -414,15 +535,35 @@ class TicketController extends Controller
             'agents'         => $agents,
             'priorities'     => $priorities,
             'ticketStatuses' => TicketStatus::orderBy('sort_order')->get(),
+            /*
+             * WHAT DELETING THIS WOULD TAKE WITH IT — #1567.
+             *
+             * The delete confirm was the generic "This cannot be undone.", which
+             * told an agent tidying up the surviving ticket of a merge nothing
+             * about the tickets folded into it. `destroy()` now un-merges them
+             * rather than stranding them, and this is how the confirm can say so
+             * before the click. Numbers only, and only for the manager who is
+             * offered Delete at all.
+             */
+            'mergedSources'  => $isAgent && $this->isManager($ticket->group_id)
+                ? Ticket::where('merged_into_id', $ticket->id)
+                    ->where('status', Ticket::STATUS_MERGED)
+                    ->orderBy('id')->pluck('number')->all()
+                : [],
         ]);
     }
 
-    public function edit(Ticket $ticket): Response
+    /** @return Response|\Illuminate\Http\RedirectResponse — merged tickets are sent back to Show. */
+    public function edit(Ticket $ticket)
     {
         if (!$this->isAgent($ticket->group_id)) {
             abort(403);
         }
 
+        if ($refusal = $this->refuseIfMerged($ticket)) {
+            return $refusal;
+        }
+
         $ticket->load(['group', 'priority', 'project']);
         $priorities = PriorityLevel::orderBy('sort_order')->get();
         $agentIds = TicketingAgentAccess::where('group_id', $ticket->group_id)->pluck('user_id');
@@ -434,6 +575,16 @@ class TicketController extends Controller
             'priorities' => $priorities,
             'agents' => $agents,
             'projects' => $projects,
+            /*
+             * The form's Status select used to hard-code five slugs, so any ticket
+             * whose status was not one of them — `merged`, or any status added on
+             * the Statuses settings tab — rendered with nothing selected and the
+             * first save silently rewrote the status to whatever the operator
+             * happened to leave showing. Same defect as #920, one layer up: drive
+             * the options from the same table `update()` validates against.
+             */
+            'ticketStatuses' => TicketStatus::where('slug', '!=', Ticket::STATUS_MERGED)
+                ->orderBy('sort_order')->get(),
         ]);
     }
 
@@ -443,6 +594,10 @@ class TicketController extends Controller
             abort(403);
         }
 
+        if ($refusal = $this->refuseIfMerged($ticket)) {
+            return $refusal;
+        }
+
         // Determine effective group (may be changing via a transfer)
         $targetGroupId = $request->filled('group_id')
             ? (int) $request->input('group_id')
@@ -454,7 +609,7 @@ class TicketController extends Controller
             ->toArray();
 
         // Build valid status list from DB (exclude 'merged' — set only by the merge operation)
-        $validStatusSlugs = TicketStatus::where('slug', '!=', 'merged')->pluck('slug')->implode(',');
+        $validStatusSlugs = TicketStatus::where('slug', '!=', Ticket::STATUS_MERGED)->pluck('slug')->implode(',');
 
         $rules = [
             'title'       => 'sometimes|required|string|max:255',
@@ -563,7 +718,7 @@ class TicketController extends Controller
     {
         $validated = $request->validate([
             'view_mode' => 'sometimes|in:list,kanban',
-            'filter'    => 'sometimes|in:all,mine,unassigned,pending,resolved',
+            'filter'    => 'sometimes|in:'.implode(',', self::VIEW_FILTERS),
         ]);
 
         if (empty($validated)) {
@@ -577,14 +732,110 @@ class TicketController extends Controller
         return response()->json(['ok' => true]);
     }
 
+    /**
+     * DELETE, WITHOUT STRANDING WHAT WAS MERGED IN — [central-ticketing] #1567.
+     *
+     * `merged_into_id` is `nullOnDelete()`, so this used to be a one-liner that
+     * quietly broke every ticket folded into the row it deleted: pointer blanked,
+     * `status = 'merged'` left behind, permanently read-only, missing from the
+     * Merged view. {@see StrandedMerge::handleTargetDeletion()} is the whole fix,
+     * and it runs INSIDE the transaction and BEFORE the delete — it needs the
+     * doomed row's number for the system notes it writes, and its own
+     * `merged_into_id` to re-point the sources up the chain.
+     *
+     * The flash names what happened, because the agent who deleted this ticket
+     * was not looking at those tickets and has no other way to find out.
+     */
     public function destroy(Ticket $ticket)
     {
         if (!$this->isManager($ticket->group_id)) {
             abort(403);
         }
 
-        $ticket->delete();
-        return redirect()->route('ticketing.index');
+        $number = $ticket->number;
+
+        $handled = DB::transaction(function () use ($ticket) {
+            $handled = StrandedMerge::handleTargetDeletion($ticket, 'user '.Auth::id());
+            $ticket->delete();
+
+            return $handled;
+        });
+
+        return redirect()->route('ticketing.index')
+            ->with('success', $this->deletionFlash($number, $handled));
+    }
+
+    /**
+     * One sentence per thing that happened to somebody else's ticket. #1567.
+     *
+     * @param array{repointed: list<string>, unmerged: list<string>, cleared: list<string>} $handled
+     */
+    private function deletionFlash(string $number, array $handled): string
+    {
+        $parts = ["Ticket {$number} deleted."];
+
+        if ($handled['unmerged'] !== []) {
+            $parts[] = sprintf(
+                '%s %s merged into it and %s been un-merged (status %s) so %s stay usable: %s.',
+                count($handled['unmerged']),
+                count($handled['unmerged']) === 1 ? 'ticket was' : 'tickets were',
+                count($handled['unmerged']) === 1 ? 'has' : 'have',
+                Ticket::STATUS_UNMERGED,
+                count($handled['unmerged']) === 1 ? 'it' : 'they',
+                implode(', ', $handled['unmerged']),
+            );
+        }
+
+        if ($handled['repointed'] !== []) {
+            $parts[] = sprintf(
+                '%s %s merged into it and %s now recorded as merged into its own merge target: %s.',
+                count($handled['repointed']),
+                count($handled['repointed']) === 1 ? 'ticket was' : 'tickets were',
+                count($handled['repointed']) === 1 ? 'is' : 'are',
+                implode(', ', $handled['repointed']),
+            );
+        }
+
+        return implode(' ', $parts);
+    }
+
+    /**
+     * UN-MERGE A STRANDED TICKET — [central-ticketing] #1567.
+     *
+     * The recovery for the rows minted before `destroy()` learned to clean up
+     * after itself: `status = 'merged'` with no `merged_into_id`, read-only on the
+     * server (#920 reads the status) and pointing at nothing, so there was no
+     * sequence of clicks that could free one. This is that sequence.
+     *
+     * Scoped to {@see Ticket::isStrandedMerge()} and nothing else, so it cannot be
+     * used to un-merge a LIVE merge — a ticket whose target still exists is
+     * correctly read-only and stays that way.
+     */
+    public function unmerge(Ticket $ticket)
+    {
+        if (! $this->isAgent($ticket->group_id)) {
+            abort(403);
+        }
+
+        if (! $ticket->isStrandedMerge()) {
+            // Not an error: the button only renders on a stranded row, so getting
+            // here means a colleague already dealt with it, or the ticket is
+            // merged into something that still exists.
+            return redirect()->route('ticketing.show', $ticket)
+                ->with('success', $ticket->isMerged()
+                    ? 'That ticket is merged into a ticket that still exists — nothing to un-merge.'
+                    : 'That ticket is not merged — nothing to un-merge.');
+        }
+
+        StrandedMerge::release(
+            $ticket,
+            'The ticket this one had been merged into no longer exists, so this ticket was '
+            .'un-merged and is editable again.',
+            'user '.Auth::id(),
+        );
+
+        return redirect()->route('ticketing.show', $ticket)
+            ->with('success', "Ticket {$ticket->number} is un-merged and is no longer read-only.");
     }
 
     /**
@@ -609,7 +860,7 @@ class TicketController extends Controller
         if ($source->id === $ticket->id) {
             return back()->withErrors(['source_number' => 'Cannot merge a ticket into itself.']);
         }
-        if ($source->status === 'merged') {
+        if ($source->isMerged()) {
             return back()->withErrors(['source_number' => 'That ticket has already been merged.']);
         }
         if (! $this->isAgent($source->group_id)) {
@@ -638,7 +889,7 @@ class TicketController extends Controller
 
             // Mark source as merged
             $source->update([
-                'status'         => 'merged',
+                'status'         => Ticket::STATUS_MERGED,
                 'merged_into_id' => $ticket->id,
             ]);
         });
@@ -647,6 +898,48 @@ class TicketController extends Controller
             ->with('success', "Ticket {$source->number} merged in.");
     }
 
+    /**
+     * MARK ONE INCONSISTENT ROW AS MERGED — option B of [central-ticketing] #938.
+     *
+     * The rows the merge bug minted carry `merged_into_id` while their status
+     * says `open`. #920 left them editable ON PURPOSE, so that they could be
+     * corrected in the product; this is the correction, and until it existed the
+     * only way to make one was to type the right status into the Edit form and
+     * know that `merged` was not in the list.
+     *
+     * Note what it is NOT: it is not `update()` with a status of `merged`, which
+     * `refuseIfMerged()` would have to be weakened to allow, and it does not
+     * touch messages, participants or any field somebody edited after the merge.
+     * It writes one column, on a row that is provably in the broken shape, and
+     * it is a no-op on anything else — so a double-click, a stale page and a row
+     * a colleague fixed thirty seconds ago all land somewhere harmless.
+     */
+    public function markMerged(Ticket $ticket)
+    {
+        if (! $this->isAgent($ticket->group_id)) {
+            abort(403);
+        }
+
+        if (! $ticket->isInconsistentlyMerged()) {
+            // Deliberately not an error: the button is only rendered on a row in
+            // the broken shape, so arriving here means somebody else has already
+            // fixed it, and being told so is the right answer.
+            //
+            // #1567 gave `merged_inconsistent` a second shape, and "already
+            // consistent" would be a lie on one of them: a stranded row is still
+            // flagged, and what it needs is `unmerge()`, not this.
+            return redirect()->route('ticketing.show', $ticket)
+                ->with('success', $ticket->isStrandedMerge()
+                    ? 'That ticket is merged into a ticket that no longer exists — un-merge it instead.'
+                    : 'That ticket is already consistent — nothing to fix.');
+        }
+
+        MergedTicketRepair::repair($ticket, 'user '.Auth::id());
+
+        return redirect()->route('ticketing.show', $ticket)
+            ->with('success', "Ticket {$ticket->number} is marked merged and is read-only again.");
+    }
+
     /**
      * Split this ticket — create a copy with a new number, same metadata, duplicated messages.
      */
@@ -656,6 +949,10 @@ class TicketController extends Controller
             abort(403);
         }
 
+        if ($refusal = $this->refuseIfMerged($ticket)) {
+            return $refusal;
+        }
+
         $newTicket = DB::transaction(function () use ($ticket) {
             $group  = TicketingGroup::findOrFail($ticket->group_id);
             $number = $group->nextTicketNumber();
@@ -754,6 +1051,10 @@ class TicketController extends Controller
             abort(403);
         }
 
+        if ($refusal = $this->refuseIfMerged($ticket, stayPut: true)) {
+            return $refusal;
+        }
+
         $validated = $request->validate([
             'user_id' => 'required|integer|exists:users,id',
         ]);
@@ -775,6 +1076,10 @@ class TicketController extends Controller
             abort(403);
         }
 
+        if ($refusal = $this->refuseIfMerged($ticket, stayPut: true)) {
+            return $refusal;
+        }
+
         TicketParticipant::where('ticket_id', $ticket->id)
             ->where('user_id', $userId)
             ->delete();
@@ -786,6 +1091,66 @@ class TicketController extends Controller
      * Search users by name/email — for the participant picker.
      * Returns up to 10 matches, excluding existing participants and the submitter.
      */
+    /**
+     * WHO TO ADD AS A PARTICIPANT — and it answers in CHIPS (#1598).
+     *
+     * The operator, 11:46 PDT 2026-09-10, having just had the device picker
+     * converted: *"are there other places we can search users where we're not
+     * using the chips? please go through and check."* This endpoint was one of
+     * the six the lead's audit found that were not, and it is central-ticketing's.
+     *
+     * It returned `DB::table('users')->get(['id', 'name', 'email'])`, so the
+     * picker drew a name and an address per row and nothing else: no role dot to
+     * tell an agent that "D. Ellis" is the child rather than the parent of the
+     * same surname, and — because those two fields were once the WHOLE of a chip
+     * — a school that configures the student chip to grade + homeroom would have
+     * been left with this one picker still showing an address.
+     *
+     * `PersonChip::rows()` is the shared serializer and this is now the same
+     * answer, key for key, as `admin.settings.users.search` — which is the point
+     * rather than a coincidence: `TicketParticipantsAreChipsTest` compares the
+     * two payloads against each other instead of against a literal list, so a
+     * key added to the platform's row cannot skip this surface.
+     *
+     * WHO IS SEARCHABLE DOES NOT CHANGE. Same `like` on name-or-email, same
+     * two-character floor, same limit of 10, same exclusion of the people
+     * already on the ticket, and `User` carries no global scope or soft delete
+     * that `DB::table('users')` did not — measured against the model on
+     * 2026-09-10. The card was explicit that this one is about the DRAWING.
+     *
+     * Two things about the query are not cosmetic:
+     *
+     *  - `PersonChip::columns()` and not `['id', 'name', 'email']`. A chip line
+     *    may name any user column, and a constrained select hands the helper a
+     *    model whose attribute is simply ABSENT — indistinguishable from a
+     *    person who has no value, so the line is blank for everybody with
+     *    nothing failing. `PersonChip::columns()`' own docblock has the trap;
+     *    `PersonChipSurfacesTest::test_a_chip_is_never_built_from_a_hand_written_select`
+     *    is the shell's guard against it.
+     *  - The name-or-email `like` stays inside its own closure. Flattened beside
+     *    the exclusion it would be an `OR` at the top level and an address match
+     *    would smuggle a person already on the ticket back into the list — the
+     *    operator-precedence hole the same shape opened on [central-inventory]
+     *    #1594.
+     *
+     * AN ORDER AT ALL is new, and it is `PersonNames::orderUsers()` rather than
+     * `orderBy('name')`. The old query had no order, so ten rows arrived in
+     * whatever sequence the storage engine happened to return them and the same
+     * two letters could list the same people differently twice running. But the
+     * column that makes an order CONSISTENT is not automatically the one that
+     * makes it READABLE: `users.name` is the cached "First Last" ("Andrew Fast")
+     * and these rows are chips, which read "Last, First" ("Fast, Andrew"). A
+     * list labelled one way and collated the other is what an operator calls
+     * unsorted — "Toews, Fast, Ivanov, Mwangi, Bergman" is perfectly ordered by
+     * a string the row no longer shows. `PersonNames::orderUsers()` is the
+     * platform's one answer to that (#524), it is what the reference search
+     * (`admin.settings.users.search`) and the sibling conversions use, and it
+     * honours the operator's `name_format` rather than assuming surname-first.
+     *
+     * It also decides WHICH TEN come back, not merely their sequence, so this is
+     * not cosmetic: on a common surname the limit falls on a different set of
+     * people under the two collations.
+     */
     public function searchUsers(Request $request, Ticket $ticket)
     {
         if (! $this->isAgent($ticket->group_id)) {
@@ -803,16 +1168,16 @@ class TicketController extends Controller
             ->unique()
             ->values();
 
-        $users = DB::table('users')
-            ->where(function ($query) use ($q) {
+        return response()->json(PersonChip::rows(
+            User::where(function ($query) use ($q) {
                 $query->where('name', 'like', "%{$q}%")
                       ->orWhere('email', 'like', "%{$q}%");
             })
-            ->whereNotIn('id', $excludeIds)
-            ->limit(10)
-            ->get(['id', 'name', 'email']);
-
-        return response()->json($users);
+                ->whereNotIn('id', $excludeIds)
+                ->tap(fn ($query) => PersonNames::orderUsers($query))
+                ->limit(10)
+                ->get(PersonChip::columns())
+        ));
     }
 
     public function myTickets(): Response

src/Http/Controllers/TicketMessageController.php

@@ -29,6 +29,19 @@ class TicketMessageController extends Controller
             abort(403);
         }
 
+        /*
+         * A merged ticket takes no new messages — [central-ticketing] #920.
+         *
+         * Show.vue replaces the composer with "This ticket has been merged and is
+         * read-only.", and that was the whole of the guard: a POST straight to this
+         * route (or from a page that was already open when the merge happened) still
+         * wrote a message onto a ticket whose thread has moved to the merge target,
+         * where nobody working the ticket would ever see it.
+         */
+        if ($ticket->isMerged()) {
+            return back()->withErrors(['ticket' => Ticket::READ_ONLY_REASON]);
+        }
+
         $validated = $request->validate([
             'body' => 'required|string',
             'is_internal' => 'boolean',

src/Http/Controllers/TicketingSettingsController.php

@@ -9,6 +9,7 @@ use Dashboard\Ticketing\Models\TicketingAgentAccess;
 use Dashboard\Ticketing\Models\TicketingGroup;
 use Dashboard\Ticketing\Models\TicketingProject;
 use Dashboard\Ticketing\Models\TicketStatus;
+use Dashboard\Ticketing\Support\MergedTicketRepair;
 use Illuminate\Http\Request;
 use Illuminate\Routing\Controller;
 use Illuminate\Support\Facades\Auth;
@@ -121,6 +122,11 @@ class TicketingSettingsController extends Controller
             'isBootstrap'      => $isBootstrap,
             'isSiteAdmin'      => $this->isSiteAdmin(),
             'autoCloseDays'    => (int) Setting::get('ticketing.auto_close_days', 0),
+            // #938 — the deploy-time repair, and how many rows it would touch. The
+            // count is what turns an abstract toggle into a decision somebody can
+            // actually make, so it is shown beside it whether the toggle is on or off.
+            'autoRepairMerged' => MergedTicketRepair::enabledOnDeploy(),
+            'inconsistentMergedCount' => MergedTicketRepair::count(),
         ]);
     }
 
@@ -575,10 +581,20 @@ class TicketingSettingsController extends Controller
 
         $validated = $request->validate([
             'auto_close_days' => 'required|integer|min:0|max:365',
+            'auto_repair_merged_on_deploy' => 'sometimes|boolean',
         ]);
 
         Setting::set('ticketing.auto_close_days', $validated['auto_close_days']);
 
+        // #938 option A is a behaviour rule, so it is a setting, and it defaults
+        // off: a deploy must never rewrite rows nobody asked it to rewrite.
+        if (array_key_exists('auto_repair_merged_on_deploy', $validated)) {
+            Setting::set(
+                MergedTicketRepair::SETTING,
+                $validated['auto_repair_merged_on_deploy'] ? '1' : '0',
+            );
+        }
+
         return back()->with('success', 'Automation settings saved.');
     }
 }

src/Models/Ticket.php

@@ -2,12 +2,39 @@
 
 namespace Dashboard\Ticketing\Models;
 
+use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 
 class Ticket extends Model
 {
+    /** Set only by TicketController::merge(); never offered by any form. */
+    public const STATUS_MERGED = 'merged';
+
+    /**
+     * WHERE AN UN-MERGED TICKET LANDS — [central-ticketing] #1567.
+     *
+     * A merge is a way of closing a ticket, so a ticket that is un-merged because
+     * its target was deleted goes to `closed` and not to `open`: it stays out of
+     * the All Open / Mine / Unassigned work queues, exactly as it was before, and
+     * the only thing that changes is that it is no longer read-only, so an agent
+     * can reopen it, reply to it or reassign it. Un-merging to `open` would push
+     * somebody's tidied-away ticket back into a live queue without being asked.
+     *
+     * It is one of the six values the `tickets.status` ENUM allows and it is
+     * `is_closed` in `ticketing_statuses`, so both the column and every count
+     * that reads `$closedSlugs` already understand it.
+     */
+    public const STATUS_UNMERGED = 'closed';
+
+    /**
+     * What every surface says when a write to a merged ticket is refused. The Show
+     * page has displayed this sentence since merge shipped; #920 was that it was
+     * only ever a sentence, with no server-side guard behind it.
+     */
+    public const READ_ONLY_REASON = 'This ticket has been merged and is read-only.';
+
     protected $fillable = [
         'number', 'group_id', 'submitter_id', 'assigned_to', 'project_id',
         'title', 'description', 'status', 'priority_id', 'due_date', 'merged_into_id',
@@ -27,6 +54,23 @@ class Ticket extends Model
     // value) still stores the right day — measured in UTC and in
     // America/New_York. So nothing was ever lost in the database; the value
     // simply had no way of reaching the screen.
+    /**
+     * `merged_inconsistent` rides on every serialized ticket — #938.
+     *
+     * The badge and its "Mark merged" button are rendered per ROW, on the index
+     * list, in the detail pane and on the Show header, so the page needs the
+     * answer for each ticket it draws. Handing it the model's own predicate
+     * rather than letting three Vue files each write
+     * `t.merged_into_id && t.status !== 'merged'` is what keeps the client's idea
+     * of "inconsistent" from drifting away from the scope the repair uses.
+     * It costs no query — both columns are already loaded.
+     *
+     * #1567 added `merged_stranded` beside it, for the same reason: there are now
+     * TWO ways a merge can fail to add up and they need different offers, so the
+     * page is handed which one it is rather than working it out from the columns.
+     */
+    protected $appends = ['merged_inconsistent', 'merged_stranded'];
+
     protected $casts = [
         'due_date' => 'date:Y-m-d',
     ];
@@ -70,4 +114,138 @@ class Ticket extends Model
     {
         return $this->belongsTo(Ticket::class, 'merged_into_id');
     }
+
+    /**
+     * A merged ticket is read-only — its messages and attachments now live on the
+     * ticket it was merged into, so it is a stub kept for its reference number and
+     * the audit trail, not a ticket anyone can still work.
+     *
+     * `status === 'merged'` and NOT `merged_into_id !== null`, deliberately. #920
+     * minted rows with `status = 'open', merged_into_id = 56` — the very rows this
+     * guard exists to prevent — and reading the id would make each of those
+     * permanently uneditable, i.e. a row the product will not let anyone correct.
+     * The status is the state; the id is the pointer that goes with it.
+     */
+    public function isMerged(): bool
+    {
+        return $this->status === self::STATUS_MERGED;
+    }
+
+    /**
+     * THE SHAPE THE MERGE BUG MINTED — [central-ticketing] #938.
+     *
+     * `merged_into_id` points at a target while `status` is something other than
+     * `merged`: the row was merged, and then a save through the unguarded Edit
+     * form (#920) put the status back. #920 stopped new ones being made and
+     * deliberately left the existing ones EDITABLE — `isMerged()` reads the
+     * status, not the pointer — so that the office can correct one rather than
+     * needing SQL. This is the predicate that finds them.
+     *
+     * It is one definition and three callers read it: the badge that offers the
+     * fix, the `mark-merged` verb that applies it one row at a time, and the
+     * repair migration that applies it to all of them at once. Two spellings of
+     * "inconsistent" that drifted apart would mean a badge on a row the repair
+     * skips.
+     */
+    public function scopeInconsistentlyMerged(Builder $query): Builder
+    {
+        return $query->whereNotNull('merged_into_id')
+            ->where('status', '!=', self::STATUS_MERGED);
+    }
+
+    /** The row-level twin of {@see scopeInconsistentlyMerged()}. */
+    public function isInconsistentlyMerged(): bool
+    {
+        return $this->merged_into_id !== null && ! $this->isMerged();
+    }
+
+    /**
+     * THE OTHER DIRECTION — [central-ticketing] #1567.
+     *
+     * `status = 'merged'` with NOTHING to point at. `merged_into_id` carries
+     * `nullOnDelete()`, so deleting the ticket that others had been merged INTO
+     * used to blank their pointer and leave the status behind: a row that
+     * {@see isMerged()} still calls read-only, whose banner names a ticket that
+     * no longer exists, and which the Merged view — scoped by the pointer — could
+     * not list. Nothing in the product could act on it.
+     *
+     * `destroy()` no longer mints these ({@see \Dashboard\Ticketing\Support\StrandedMerge}),
+     * but the rows already made are still out there, so the shape needs a name:
+     * this is what the badge offers to un-merge and what the Merged view now
+     * includes.
+     *
+     * Deliberately NOT folded into {@see scopeInconsistentlyMerged()}: that scope
+     * is what #938's repair writes `status = 'merged'` over, and a stranded row
+     * already HAS that status — repairing it would match forever and write
+     * nothing, which is exactly the idempotency the repair guarantees.
+     */
+    public function scopeStrandedMerge(Builder $query): Builder
+    {
+        return $query->where('status', self::STATUS_MERGED)
+            ->whereNull('merged_into_id');
+    }
+
+    /** The row-level twin of {@see scopeStrandedMerge()}. */
+    public function isStrandedMerge(): bool
+    {
+        return $this->isMerged() && $this->merged_into_id === null;
+    }
+
+    /**
+     * EITHER shape of a merge that does not add up — #938's and #1567's.
+     *
+     * The two are mutually exclusive by construction (one has a pointer and the
+     * wrong status, the other has the right status and no pointer), and the
+     * badge, the sidebar's warning count and `merged_inconsistent` all want the
+     * union: "this row's status and its pointer disagree, whichever way round".
+     * The repair scopes stay separate because the fixes differ.
+     */
+    public function scopeMergeInconsistent(Builder $query): Builder
+    {
+        return $query->where(function (Builder $q) {
+            $q->where(fn (Builder $i) => $i->inconsistentlyMerged())
+                ->orWhere(fn (Builder $s) => $s->strandedMerge());
+        });
+    }
+
+    /**
+     * Every row that carries the merge shape AT ALL — what the Merged view lists.
+     *
+     * Pointer set (whatever the status: #938's rows included) or status `merged`
+     * (whether or not the pointer survived: #1567's stranded rows included).
+     * Scoping the view by the pointer alone dropped a stranded row out of the one
+     * view whose whole job is showing merges, leaving it visible only under
+     * Resolved — so a reader looking for merged tickets never found it.
+     */
+    public function scopeEverMerged(Builder $query): Builder
+    {
+        return $query->where(function (Builder $q) {
+            $q->whereNotNull('merged_into_id')
+                ->orWhere('status', self::STATUS_MERGED);
+        });
+    }
+
+    /**
+     * @see $appends — the same answer, for the page.
+     *
+     * #1567 widened this to the union: a stranded row is inconsistent in the
+     * plainest sense (it says it is merged into nothing), and the flag existing
+     * while reading `false` on exactly that row was half of what the card
+     * reported.
+     */
+    public function getMergedInconsistentAttribute(): bool
+    {
+        return $this->isInconsistentlyMerged() || $this->isStrandedMerge();
+    }
+
+    /**
+     * @see $appends — WHICH of the two shapes, for a page that must offer
+     * different fixes. `merged_inconsistent` says something is wrong;
+     * `merged_stranded` says the target is gone, so the offer is "un-merge"
+     * rather than #938's "mark merged".
+     */
+    public function getMergedStrandedAttribute(): bool
+    {
+        return $this->isStrandedMerge();
+    }
 }

src/Support/MergedTicketRepair.php

@@ -0,0 +1,133 @@
+<?php
+
+namespace Dashboard\Ticketing\Support;
+
+use App\Models\Setting;
+use Dashboard\Ticketing\Models\Ticket;
+use Illuminate\Support\Facades\Log;
+
+/**
+ * REPAIRING THE ROWS THE MERGE BUG MINTED — [central-ticketing] #938.
+ *
+ * #920 stopped the bug making new ones: a ticket whose `status` is `merged` is
+ * read-only server-side, so the Edit form can no longer write `status = open`
+ * over a row that has already been folded into another ticket. It shipped NO
+ * data change, on purpose, and its guard reads the status rather than the
+ * pointer precisely so the rows already carrying the corrupt shape
+ * (`status = open, merged_into_id = 56`) stay editable and can be corrected
+ * through the UI instead of by hand in SQL.
+ *
+ * This class is the correction, and it is deliberately ONE implementation with
+ * three callers, because "which rows are broken" and "what fixing one means"
+ * are the two things that must not drift:
+ *
+ *   - {@see \Dashboard\Ticketing\Http\Controllers\TicketController::markMerged()}
+ *     — the office fixes one row, from the badge on the ticket header.
+ *   - {@see \Dashboard\Ticketing\Console\Commands\RepairMergedTickets}
+ *     — `--dry-run` is the COUNT, and it is the whole reason the class is not
+ *     just a line inside the migration: the operator has to be able to see how
+ *     many rows there are, and which, before anything writes.
+ *   - the `2026_09_04_000001_repair_inconsistent_merged_tickets` migration
+ *     — every row at once, on deploy, and ONLY when the operator has turned
+ *     {@see SETTING} on.
+ *
+ * ── WHAT REPAIRING DOES *NOT* DO ────────────────────────────────────────────
+ *
+ * It writes `status = 'merged'` and nothing else. Messages, participants,
+ * assignee, priority and title are left exactly as they are, including edits
+ * made to the row AFTER the merge — those are somebody's work, they are the
+ * only copy, and there is no record of what the fields held before the bad
+ * save to revert them to. The ticket becoming read-only is the whole change.
+ */
+class MergedTicketRepair
+{
+    /**
+     * "Auto-repair inconsistent merged tickets on deploy", and it DEFAULTS OFF.
+     *
+     * A deploy that silently rewrites rows nobody asked it to rewrite is the one
+     * outcome #938 rules out by name, so the migration reads this and no-ops
+     * when it is unset. Off is therefore the whole behaviour of a box that has
+     * never heard of this setting, which is what makes shipping the migration
+     * safe before the operator has decided anything.
+     */
+    public const SETTING = 'ticketing.auto_repair_merged_on_deploy';
+
+    /** How many rows are inconsistent right now. The dry run, and it writes nothing. */
+    public static function count(): int
+    {
+        return Ticket::query()->inconsistentlyMerged()->count();
+    }
+
+    /**
+     * The rows themselves, for a human to look at before deciding.
+     *
+     * @return \Illuminate\Database\Eloquent\Collection<int,Ticket>
+     */
+    public static function rows()
+    {
+        return Ticket::query()->inconsistentlyMerged()->orderBy('id')->get();
+    }
+
+    /** Has the operator asked for the deploy-time repair? */
+    public static function enabledOnDeploy(): bool
+    {
+        return filter_var(Setting::get(self::SETTING, '0'), FILTER_VALIDATE_BOOLEAN);
+    }
+
+    /**
+     * Re-mark every inconsistent row as merged. Returns how many rows changed.
+     *
+     * IDEMPOTENT, and it is the scope that makes it so rather than a flag: the
+     * second run matches nothing, because the first run's rows no longer satisfy
+     * `status <> 'merged'`. So a migration that is re-run, a command run twice
+     * and a deploy that repeats all answer 0 and write nothing.
+     */
+    public static function repairAll(string $by): int
+    {
+        $numbers = Ticket::query()->inconsistentlyMerged()->pluck('number')->all();
+
+        if ($numbers === []) {
+            Log::info("[ticketing] #938 merged-ticket repair ({$by}): nothing to repair.");
+
+            return 0;
+        }
+
+        $changed = Ticket::query()->inconsistentlyMerged()->update([
+            'status' => Ticket::STATUS_MERGED,
+        ]);
+
+        // The numbers, not just the count. These rows are being made read-only,
+        // and "which ones" is the question the office will ask afterwards.
+        Log::info(sprintf(
+            '[ticketing] #938 merged-ticket repair (%s): re-marked %d ticket(s) as merged — %s',
+            $by,
+            $changed,
+            implode(', ', $numbers),
+        ));
+
+        return $changed;
+    }
+
+    /**
+     * Re-mark ONE row. Returns false when it was not inconsistent to begin with,
+     * so a double-clicked button and a stale page are both no-ops rather than a
+     * second write.
+     */
+    public static function repair(Ticket $ticket, string $by): bool
+    {
+        if (! $ticket->isInconsistentlyMerged()) {
+            return false;
+        }
+
+        $ticket->forceFill(['status' => Ticket::STATUS_MERGED])->save();
+
+        Log::info(sprintf(
+            '[ticketing] #938 merged-ticket repair (%s): re-marked %s as merged (merged into #%d).',
+            $by,
+            $ticket->number,
+            $ticket->merged_into_id,
+        ));
+
+        return true;
+    }
+}

src/Support/StrandedMerge.php

@@ -0,0 +1,202 @@
+<?php
+
+namespace Dashboard\Ticketing\Support;
+
+use Dashboard\Ticketing\Models\Ticket;
+use Dashboard\Ticketing\Models\TicketMessage;
+use Illuminate\Support\Facades\Log;
+
+/**
+ * DELETING A MERGE TARGET MUST NOT STRAND WHAT WAS MERGED INTO IT — #1567.
+ *
+ * `tickets.merged_into_id` is declared `nullOnDelete()`, so deleting a ticket
+ * that other tickets had been merged INTO used to blank their pointer and walk
+ * away, leaving `status = 'merged'` behind with nothing on the other end:
+ *
+ *   - {@see Ticket::isMerged()} still calls the row read-only, so the page drops
+ *     the status / priority / assignee selects and the reply composer, and the
+ *     only control left on it is Delete. Nothing can reopen it, reassign it or
+ *     reply to it — ever.
+ *   - the banner "This ticket has been merged and is read-only." names a merge
+ *     target that no longer exists.
+ *   - the Merged view was scoped by the pointer, so the row vanished from the one
+ *     view whose job is showing merges and turned up only under Resolved.
+ *
+ * And `destroy()` gave no hint any of this was about to happen: the confirm was
+ * the generic "This cannot be undone."
+ *
+ * ── WHAT THIS DOES INSTEAD ──────────────────────────────────────────────────
+ *
+ * {@see handleTargetDeletion()} runs inside `destroy()`'s transaction, BEFORE the
+ * row goes, and gives every ticket pointing at it somewhere real to be:
+ *
+ *   RE-POINT, when the doomed ticket was itself merged into a third ticket. The
+ *   messages genuinely did travel that far — merge moves them to the target, so
+ *   merging the target onward moved them again — and the surviving ticket at the
+ *   end of the chain really is where this ticket's content lives. This is the
+ *   answer that keeps the merge true.
+ *
+ *   UN-MERGE, otherwise. There is nowhere left to point, so the row stops
+ *   claiming to be merged: {@see Ticket::STATUS_UNMERGED} (`closed`) and a NULL
+ *   pointer, which is an ordinary closed ticket — out of the work queues, but
+ *   editable, reopenable and answerable again.
+ *
+ * Either way the source gets a system note saying which ticket was deleted and
+ * what happened to it, because the row is being changed by somebody who was
+ * looking at a different ticket entirely and its own history is the only place
+ * that will ever explain it.
+ *
+ * ── THE ROWS ALREADY OUT THERE ──────────────────────────────────────────────
+ *
+ * This stops new ones. The stranded rows prod already holds are found by
+ * {@see Ticket::scopeStrandedMerge()}, now report `merged_inconsistent`, are
+ * listed by the Merged view, and are released one at a time by
+ * {@see \Dashboard\Ticketing\Http\Controllers\TicketController::unmerge()} —
+ * which calls {@see release()} here, so "un-merged" means one thing whichever
+ * door it came through.
+ *
+ * Deliberately NOT part of {@see MergedTicketRepair}: that class repairs #938's
+ * shape by writing `status = 'merged'` onto a row that has a target. This is the
+ * opposite operation on the opposite shape, and the two must not share a scope.
+ */
+class StrandedMerge
+{
+    /** How many rows are stranded right now — status `merged`, pointer NULL. */
+    public static function count(): int
+    {
+        return Ticket::query()->strandedMerge()->count();
+    }
+
+    /**
+     * The stranded rows themselves.
+     *
+     * @return \Illuminate\Database\Eloquent\Collection<int,Ticket>
+     */
+    public static function rows()
+    {
+        return Ticket::query()->strandedMerge()->orderBy('id')->get();
+    }
+
+    /**
+     * Give every ticket merged into `$target` somewhere real to be, before
+     * `$target` is deleted. Call inside the deleting transaction.
+     *
+     * Group membership is NOT re-checked per source. A source can live in another
+     * group, and the alternative to touching it is leaving it permanently frozen
+     * — this is the delete's own clean-up, not a write the operator chose to make
+     * on that ticket.
+     *
+     * @return array{repointed: list<string>, unmerged: list<string>, cleared: list<string>}
+     *         ticket numbers, by what happened to them
+     */
+    public static function handleTargetDeletion(Ticket $target, string $by): array
+    {
+        $sources = Ticket::where('merged_into_id', $target->id)->get();
+
+        $result = ['repointed' => [], 'unmerged' => [], 'cleared' => []];
+
+        if ($sources->isEmpty()) {
+            return $result;
+        }
+
+        // Where the content actually went. `merged_into_id` is nulled when ITS
+        // target is deleted, so this is either a live ticket or nothing.
+        $chain = $target->merged_into_id;
+
+        foreach ($sources as $source) {
+            // #938's shape: the pointer is stale but the status is live, so the
+            // row is an ordinary working ticket that happens to carry a dangling
+            // id. Dropping the id is the whole fix — and it is what the FK was
+            // about to do anyway; doing it here means the row is consistent
+            // inside this transaction rather than as a side effect afterwards.
+            if (! $source->isMerged()) {
+                $source->forceFill(['merged_into_id' => null])->save();
+                $result['cleared'][] = $source->number;
+                continue;
+            }
+
+            // `$chain === $source->id` cannot be produced by `merge()` (it
+            // refuses a merged source and a self-merge), but a cycle would make
+            // the row point at itself, which is worse than un-merging it.
+            if ($chain !== null && $chain !== $source->id) {
+                $chainTicket = Ticket::find($chain);
+
+                if ($chainTicket) {
+                    $source->forceFill(['merged_into_id' => $chainTicket->id])->save();
+
+                    TicketMessage::system($source, sprintf(
+                        'Ticket %s was deleted. This ticket had been merged into it, and %s '
+                        .'had itself been merged into %s — where its messages now live — so it '
+                        .'is recorded as merged into %s.',
+                        $target->number,
+                        $target->number,
+                        $chainTicket->number,
+                        $chainTicket->number,
+                    ));
+
+                    $result['repointed'][] = $source->number;
+                    continue;
+                }
+            }
+
+            self::release(
+                $source,
+                sprintf(
+                    'Ticket %s, which this ticket had been merged into, was deleted. This '
+                    .'ticket has been un-merged so that it is no longer read-only; its status '
+                    .'is now %s.',
+                    $target->number,
+                    Ticket::STATUS_UNMERGED,
+                ),
+                $by,
+            );
+
+            $result['unmerged'][] = $source->number;
+        }
+
+        Log::info(sprintf(
+            '[ticketing] #1567 deleting %s: re-pointed %d, un-merged %d, cleared %d dangling pointer(s) (%s).',
+            $target->number,
+            count($result['repointed']),
+            count($result['unmerged']),
+            count($result['cleared']),
+            $by,
+        ));
+
+        return $result;
+    }
+
+    /**
+     * Un-merge ONE ticket: status to {@see Ticket::STATUS_UNMERGED}, pointer to
+     * NULL, and a system note saying why.
+     *
+     * `forceFill`, not `update([...])`, for the same reason the rest of the merge
+     * code uses it: this is the machinery correcting its own state, and it must
+     * not be routed through anything that treats `merged` as read-only.
+     *
+     * Returns false when the row was not merged at all, so a double-clicked
+     * button and a stale page are no-ops rather than a second write.
+     */
+    public static function release(Ticket $ticket, string $reason, string $by): bool
+    {
+        if (! $ticket->isMerged()) {
+            return false;
+        }
+
+        $ticket->forceFill([
+            'status'         => Ticket::STATUS_UNMERGED,
+            'merged_into_id' => null,
+        ])->save();
+
+        TicketMessage::system($ticket, $reason);
+
+        Log::info(sprintf(
+            '[ticketing] #1567 un-merged %s to %s (%s).',
+            $ticket->number,
+            Ticket::STATUS_UNMERGED,
+            $by,
+        ));
+
+        return true;
+    }
+}

src/TicketingServiceProvider.php

@@ -26,6 +26,7 @@ class TicketingServiceProvider extends ServiceProvider
         if ($this->app->runningInConsole()) {
             $this->commands([
                 \Dashboard\Ticketing\Console\Commands\AutoCloseTickets::class,
+                \Dashboard\Ticketing\Console\Commands\RepairMergedTickets::class,
             ]);
         }
     }

src/routes/ticketing.php

@@ -76,6 +76,10 @@ Route::middleware(['web', 'auth', 'app.access:ticketing'])
             Route::post('/{ticket}/view',                     [TicketController::class, 'recordView'])        ->name('tickets.view');
             Route::post('/{ticket}/merge',                    [TicketController::class, 'merge'])             ->name('merge');
             Route::post('/{ticket}/split',                    [TicketController::class, 'split'])             ->name('split');
+            // #938 — the one-click fix for a row the merge bug left inconsistent.
+            Route::post('/{ticket}/mark-merged',              [TicketController::class, 'markMerged'])        ->name('mark-merged');
+            // #1567 — the one-click release for a row whose merge target was deleted.
+            Route::post('/{ticket}/unmerge',                  [TicketController::class, 'unmerge'])           ->name('unmerge');
             Route::post('/{ticket}/participants',             [TicketController::class, 'addParticipant'])    ->name('participants.store');
             Route::delete('/{ticket}/participants/{userId}',  [TicketController::class, 'removeParticipant'])->name('participants.destroy');
             Route::get('/{ticket}/users/search',              [TicketController::class, 'searchUsers'])       ->name('users.search');