A language with no server to start says language server for .py not found, not that it did not answer

A question about a file whose language server is not there came back as no answer at all, which the core said as the language server did not answer. The client now answers @none language server for <ext> not found, ENOENT by its words.

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

1 files changed, 15 insertions, 0 deletions

diff --git a/src/lsp/lsp_client.zig b/src/lsp/lsp_client.zig
index 91ea67d6..7c1980f6 100644
--- a/src/lsp/lsp_client.zig
+++ b/src/lsp/lsp_client.zig
@@ -429,6 +429,8 @@ pub fn query(gpa: std.mem.Allocator, arena: std.mem.Allocator, req: lsp.Req, out
     record(si, req, us, rows, err_name);
 
     if (req.kind == .explain) return traceOut(&tr, req, out, rows, us);
+    // No server to start for the language: said, not "did not answer".
+    if (failure) |err| if (err == error.NoServer) return lsp.none(out, "language server for {s} not found", .{std.fs.path.extension(req.path)});
     if (failure) |err| return err;
     try out.writeAll(scratch.buffered());
 }
@@ -2231,3 +2233,16 @@ test "LSP source snippets preserve indentation with UTF16 byte ranges and prose
         }
     }
 }
+
+test "a language with no server to start says so, not that it did not answer" {
+    const si = specFor("/x/a.py") orelse return;
+    const was = conns[si].state;
+    conns[si].state = .disabled;
+    defer conns[si].state = was;
+    var arena: std.heap.ArenaAllocator = .init(std.testing.allocator);
+    defer arena.deinit();
+    var buf: [256]u8 = undefined;
+    var out: std.Io.Writer = .fixed(&buf);
+    try query(std.testing.allocator, arena.allocator(), .{ .kind = .hover, .path = "/x/a.py", .source = "", .offset = 0 }, &out);
+    try std.testing.expectEqualStrings("@none language server for .py not found\n", out.buffered());
+}