cli: move before you kill, and the question leaves the list standing

Killing the aria on screen closed the socket the pager was watching, which
ended the session whatever successor had been chosen. The successor is now
attended FIRST and the old aria dies after, so the pager never holds a dead
connection.

The question also set the pit aside rather than closing it: answering no puts
the listing back with its cursor where it stood.

Author: gluck

internal/cli/command.go

@@ -387,31 +387,45 @@ func (in *interactiveInput) killAria(ctx context.Context, id string, recursive b
 	if err != nil {
 		return "", err
 	}
+	// MOVE BEFORE YOU KILL. The pager holds the subject's socket; killing the
+	// aria it is watching closes that connection under the session, which
+	// ends it whatever the successor was going to be. So the successor is
+	// decided, attended, and only then does the old aria die.
 	onScreen := id == in.currentID()
-	successor := ""
-	if onScreen {
-		successor = in.successorFor(ctx, acli, id, prefer)
-	}
-	if err := acli.Kill(ctx, id, recursive); err != nil {
-		return "", fmt.Errorf("kill %s: %w", id, err)
-	}
-	in.mu.Lock()
-	in.jumps.forget(id)
-	in.mu.Unlock()
 	if !onScreen {
+		if err := acli.Kill(ctx, id, recursive); err != nil {
+			return "", fmt.Errorf("kill %s: %w", id, err)
+		}
+		in.forgetAria(id)
 		return "killed " + id, nil
 	}
+	successor := in.successorFor(ctx, acli, id, prefer)
 	if successor == "" {
+		if err := acli.Kill(ctx, id, recursive); err != nil {
+			return "", fmt.Errorf("kill %s: %w", id, err)
+		}
+		in.forgetAria(id)
 		in.leaveSession()
 		return "killed " + id + ": nothing left to attend", nil
 	}
 	note, aerr := in.attendNote(ctx, successor)
 	if aerr != nil {
 		return "", aerr
 	}
+	if err := acli.Kill(ctx, id, recursive); err != nil {
+		return "", fmt.Errorf("kill %s: %w", id, err)
+	}
+	in.forgetAria(id)
 	return "killed " + id + "; " + note, nil
 }
 
+// forgetAria drops a dead aria from the path, so no hop can land on it.
+func (in *interactiveInput) forgetAria(id string) {
+	in.mu.Lock()
+	in.jumps.forget(id)
+	in.mu.Unlock()
+}
+
 // askKill puts the question up and runs the kill only on a yes. The question
 // is drawn by the pager, so this hops onto the render lock the way every
 // other pager mutation does.

internal/cli/confirm.go

@@ -10,17 +10,25 @@ import "strings"
 // answer is swallowed) plus a pinned notice, which is the one alert that does
 // not retire on its own: it stands for exactly as long as the question does.
 
-// confirmAsk is the pending question: the sentence, and what a yes runs.
+// confirmAsk is the pending question: the sentence, what a yes runs, and the
+// pit the question was asked from, which comes back either way. A reader who
+// says no must find their list exactly where they left it.
 type confirmAsk struct {
 	prompt string
 	yes    func()
+	behind pit
 }
 
 // askConfirm puts the question up. The caller's action runs on the input
 // goroutine, so it must hand off anything that dials, exactly as every other
 // hook here does.
 func (t *transcript) askConfirm(prompt string, yes func()) {
-	t.confirm = &confirmAsk{prompt: prompt, yes: yes}
+	// THE PIT UNDERNEATH IS NOT CLOSED, it is set aside: showList would close
+	// a hosted view and drop a list's cursor, and the question is a moment,
+	// not a new place to be.
+	behind := t.pit
+	t.confirm = &confirmAsk{prompt: prompt, yes: yes, behind: behind}
+	t.pit = pit{}
 	t.pit.showList(pitConfirm, "", []pitRow{staticRow("  " + prompt + "  [y/N]")})
 	t.status.pinNotice(prompt)
 	t.focused = focusPit
@@ -30,9 +38,13 @@ func (t *transcript) askConfirm(prompt string, yes func()) {
 // clearConfirm takes the question down and the notice with it, in that order:
 // the bar must not be left holding a sentence about a question nobody can see.
 func (t *transcript) clearConfirm() {
+	ask := t.confirm
 	t.confirm = nil
 	if t.showing(pitConfirm) {
-		t.pit.close()
+		t.pit = pit{}
+		if ask != nil {
+			t.pit = ask.behind
+		}
 	}
 	t.status.setNotice("")
 }

internal/cli/confirm_test.go

@@ -69,3 +69,25 @@ func TestConfirm_TheNoticeStandsWhileTheQuestionDoes(t *testing.T) {
 		t.Fatalf("the notice must clear with the question: %q", note)
 	}
 }
+
+// The question is a moment, not a place: the list it was asked from is still
+// there afterwards, with its cursor where the reader left it.
+func TestConfirm_TheListSurvivesTheQuestion(t *testing.T) {
+	tr, _ := visualFixture(t)
+	tr.dropRow = func(pit, id, next string) {}
+	tr.pit.showList(pitOutput, ":ls", []pitRow{
+		{text: "  aria1234", id: "aria1234", yank: "aria1234"},
+		{text: "  aria5678", id: "aria5678", yank: "aria5678"},
+	})
+	tr.focused = focusPit
+	tr.pit.moveSelection(1) // stand on the second row
+	tr.key('x')
+	tr.key('n')
+	if tr.pit.id != pitOutput {
+		t.Fatalf("the listing did not come back: pit = %q", tr.pit.id)
+	}
+	row, ok := tr.pit.selected()
+	if !ok || row.id != "aria5678" {
+		t.Fatalf("the cursor moved across the question: %+v", row)
+	}
+}