Do not hold the deletes for a refusal that happened earlier

src/DiffEngineViewer.Tests/HeldDeleteTests.cs

@@ -0,0 +1,69 @@
+/// <summary>
+/// When a sweep holds its deletes. A snapshot moving inline arrives as two unrelated entries - the
+/// patch and a delete of the verified file it replaces - so a patch the applier will not take must
+/// stop the delete, or the snapshot loses both copies at once.
+/// </summary>
+public class HeldDeleteTests
+{
+    /// <summary>
+    /// A refusal recorded on a conflicted entry belongs to the targeted accept that made it, not
+    /// to the batch reading it. A bulk accept hands conflicted entries back untouched, so that
+    /// status sat there and held every pending delete on every later accept-all, citing a refusal
+    /// that had not happened.
+    /// </summary>
+    [Test]
+    public async Task A_refusal_left_on_a_conflicted_entry_does_not_hold_a_later_sweep()
+    {
+        var state = Conflicted();
+
+        // One variant accepted on its own, and refused - the file was locked, say. The entry
+        // stays, conflicted still, and carries what the applier said
+        var refused = ViewerSession.Apply(
+            state,
+            CommandKind.Accept,
+            Sweeping(InlineApplyResult.Failed("Failed to write: BTests.cs")));
+        await Assert.That(refused.Queue.Single(_ => _.Kind == QueueEntryKind.Inline).Status).IsNotNull();
+
+        var swept = ViewerSession.Apply(refused, CommandKind.AcceptAll, Sweeping(InlineApplyResult.Applied));
+        await Assert.That(swept.Queue.Where(_ => _.Kind == QueueEntryKind.Delete)).IsEmpty();
+    }
+
+    /// <summary>
+    /// The reason the read exists at all: a patch this batch could not write still holds the
+    /// deletes.
+    /// </summary>
+    [Test]
+    public async Task A_refusal_in_this_sweep_holds_the_deletes()
+    {
+        var state = ViewerSession.EnqueueTracked(
+            Fixtures.Inline(Fixtures.Patch("A.cs", 1)),
+            Fixtures.Delete());
+
+        var swept = ViewerSession.Apply(
+            state,
+            CommandKind.AcceptAll,
+            Sweeping(InlineApplyResult.NotFound("Could not locate the VerifyInline call")));
+
+        var delete = swept.Queue.Single(_ => _.Kind == QueueEntryKind.Delete);
+        await Assert.That(delete.Status).StartsWith("Held:");
+    }
+
+    /// <summary>
+    /// A delete that is actually deletable, so that a held one and a failed one cannot be confused
+    /// for each other: the fixture's default actions throw for anything touching a file.
+    /// </summary>
+    static ViewerActions Sweeping(InlineApplyResult result) =>
+        Fixtures.Applying(result) with
+        {
+            DeleteFile = static _ =>
+            {
+            }
+        };
+
+    static SessionState Conflicted() =>
+        ViewerSession.EnqueueTracked(
+            Fixtures.Inline(
+                Fixtures.Patch(content: "eight", framework: "net8.0"),
+                Fixtures.Patch(content: "nine", framework: "net9.0")),
+            Fixtures.Delete());
+}

src/DiffEngineViewer/ViewerSession.cs

@@ -630,8 +630,12 @@ static SessionState SweepTracked(
     /// not the last copy of it leaving.
     /// </para>
     /// <para>
-    /// A status on an inline entry is the outcome of an attempt, so this reads failures only:
-    /// conflicted entries that a bulk accept skips are handed back untouched and carry none.
+    /// A status on an inline entry is the outcome of an attempt, and this has to read only the
+    /// attempts the sweep it is answering for made. A bulk accept skips conflicted entries and
+    /// hands them back exactly as they were, so a status on one of those was left by a targeted
+    /// accept of a single variant, at some earlier point - and reading it held every pending
+    /// delete on every accept-all after it, citing a refusal in a batch that never touched the
+    /// entry. Everything else left in the queue with a status was tried and refused just now.
     /// Discarding asks nothing of the patches, so it sweeps as it always did.
     /// </para>
     /// </summary>
@@ -644,7 +648,7 @@ static bool InlineRefused(IReadOnlyList<QueueEntry> queue, bool discarding)
 
         foreach (var entry in queue)
         {
-            if (entry is {Kind: QueueEntryKind.Inline, Status: not null})
+            if (entry is {Kind: QueueEntryKind.Inline, Conflicted: false, Status: not null})
             {
                 return true;
             }