Lspinfo's exec answer is the +Lsp pane it fills: any language answer that fills a pane answers that pane, made or filled again

The answer was taken from the asking pane's search pane, which a
listing like +Lsp never sets, so Lspinfo answered the file pane. The
pane the answer filled is now known from what fillResults made or
refilled, whatever kind of listing it is.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

2 files changed, 15 insertions, 4 deletions

diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index 3b3873e3..5827a4ed 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -4294,3 +4294,13 @@ test "Find ends with what it skipped, and a Find or Grep that finds nothing leav
     try testing.expectEqualStrings(before, search.file.?.content);
     try testing.expect(th.logHas(p, "Find: name not found"));
 }
+
+test "Lspinfo's answer is the +Lsp pane it fills, as a Rename preview's is its +Search" {
+    const p = try withFile(testing.allocator, "x\n");
+    defer p.deinit();
+    p.fs.lsp_result = null;
+    p.lspRequest(p.active, .status, "");
+    p.lspResponse(p.lsp_wait.?.id, "backend: lsp-client\n");
+    const shown = p.paneBySerial(p.fs.lsp_result.?).?;
+    try testing.expect(std.mem.endsWith(u8, p.panes[shown].?.file.?.path, "+Lsp"));
+}
diff --git a/src/pardes.zig b/src/pardes.zig
index b15cfb00..2b0ed8f0 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -6760,15 +6760,16 @@ pub const Pardes = struct {
 
         const dir = if (pane.file) |f| (std.fs.path.dirname(f.path) orelse "/") else pane.cwdSlice();
         const content = p.gpa.dupe(u8, rows) catch return;
+        const serial_before = p.next_serial;
+        p.fs.refilled = null;
         panes.Output.fillResults(p, w.pane, dir, from, w.arg.slice(), content, null) catch |err| {
             p.reportError(w.pane, "language response", err);
             return;
         };
         // What a 9P write that asked it answers: the pane the rows are in
-        // (a multi-file Rename's preview), not the pane it was asked from.
-        if (pane.search_pane) |rid| if (p.panes[rid]) |rp| {
-            p.fs.lsp_result = rp.serial;
-        };
+        // (a multi-file Rename's preview, Lspinfo's +Lsp), made or filled
+        // again, not the pane it was asked from.
+        p.fs.lsp_result = if (p.next_serial != serial_before) p.next_serial else p.fs.refilled;
         if (w.kind == .rename) {
             var said_buf: [128]u8 = undefined;
             // Rows that only name a file the server left alone (lsp_client