fix(lsp): 拉取诊断客户端不再重复收到 push 诊断

initialize 记录 textDocument.diagnostic 能力；客户端支持 pull 时不再发送 publishDiagnostics，避免 Problems 面板重复。gate2 增加溢出诊断断言：仅 1 条、range 覆盖完整字面量、错误恢复后函数语义 token 仍在，并验证 pull 客户端不会同时收到 push。

App/lib/lsp/LspServer.vp

@@ -33,6 +33,10 @@ define LSP_CANCEL_CAP = 64
 _cancel_int: list[int]* = None
 _cancel_str: list[str]* = None
 
+# 1 when the client advertises pull diagnostics (`textDocument.diagnostic`). Pushing
+# publishDiagnostics as well would show every problem twice in the Problems panel.
+_pull_diagnostics: int = 0
+
 
 def _CancelAdd(pool: memhub.MemManager*, id_node: json.JsonValue*):
     if id_node is None:
@@ -146,9 +150,24 @@ def _BuildInitializeResult(pool: memhub.MemManager*) -> json.JsonValue*:
     return result
 
 
+def _ClientSupportsPull(params: json.JsonValue*) -> int:
+    """Whether initialize params advertise textDocument/diagnostic (pull diagnostics)."""
+    if params is None:
+        return 0
+    caps: json.JsonValue* = params["capabilities"]
+    if caps is None:
+        return 0
+    td: json.JsonValue* = caps["textDocument"]
+    if td is None:
+        return 0
+    return 1 if td["diagnostic"] is not None else 0
+
+
 def _HandleInitialize(pool: memhub.MemManager*, tr: LspTransport.LspTransport*,
                       ws: LspWorkspace.LspWorkspace*, id_node: json.JsonValue*,
                       params: json.JsonValue*) -> int:
+    global _pull_diagnostics
+    _pull_diagnostics = _ClientSupportsPull(params)
     root_uri: str = None
     if params is not None:
         root_uri = LspRpc.GetStringField(params, "rootUri")
@@ -188,6 +207,8 @@ def _HandleDidOpen(pool: memhub.MemManager*, tr: LspTransport.LspTransport*,
     if docs.Open(uri, text, version) is None:
         LspTransport.StderrWrite("viperc-lsp: didOpen failed to store document\n")
         return -1
+    if _pull_diagnostics != 0:
+        return 0
     return LspDiagnostics.Publish(pool, tr, docs, uri)
 
 
@@ -227,6 +248,8 @@ def _HandleDidChange(pool: memhub.MemManager*, tr: LspTransport.LspTransport*,
             LspTransport.StderrWrite("viperc-lsp: didChange failed to apply a content change\n")
             return -1
         i += 1
+    if _pull_diagnostics != 0:
+        return 0
     return LspDiagnostics.Publish(pool, tr, docs, uri)
 
 
@@ -239,6 +262,8 @@ def _HandleDidClose(pool: memhub.MemManager*, tr: LspTransport.LspTransport*,
     if uri is None:
         return -1
     docs.Close(uri)
+    if _pull_diagnostics != 0:
+        return 0
     return LspDiagnostics.PublishEmpty(pool, tr, uri)
 
 
@@ -250,6 +275,8 @@ def _HandleDidSave(pool: memhub.MemManager*, tr: LspTransport.LspTransport*,
     uri: str = LspRpc.GetStringField(td, "uri")
     if uri is None:
         return -1
+    if _pull_diagnostics != 0:
+        return 0
     return LspDiagnostics.Publish(pool, tr, docs, uri)
 
 

Tools/lsp/probe.py

@@ -395,12 +395,72 @@ def gate2(exe: str) -> int:
     if not isinstance(diagnostics, list) or len(diagnostics) != 0:
         raise AssertionError(f"didClose did not clear diagnostics: {publish}")
 
+    # Lexer overflow: exactly one diagnostic, the range covers the whole literal, and the rest of
+    # the file keeps its symbols/semantic tokens (recovery parsing).
+    overflow = "def a(l: int):\n    pass\n\ndef main():\n    a(1024000000000000000000)\n"
+    client.notify(
+        "textDocument/didOpen",
+        {"textDocument": {"uri": uri, "languageId": "viper", "version": 3, "text": overflow}},
+    )
+    publish = client.wait_notification("textDocument/publishDiagnostics")
+    diagnostics = publish.get("params", {}).get("diagnostics")
+    if not isinstance(diagnostics, list) or len(diagnostics) != 1:
+        raise AssertionError(f"expected exactly one overflow diagnostic: {publish}")
+    overflow_diag = diagnostics[0]
+    if overflow_diag["range"]["start"] != {"line": 4, "character": 6} or \
+            overflow_diag["range"]["end"] != {"line": 4, "character": 28}:
+        raise AssertionError(f"overflow range does not cover the literal: {overflow_diag}")
+    if "1024000000000000000000" not in overflow_diag["message"]:
+        raise AssertionError(f"overflow diagnostic lost the literal text: {overflow_diag}")
+    sem = client.request(
+        "textDocument/semanticTokens/full", {"textDocument": {"uri": uri}}, timeout=120.0
+    ).get("result")
+    sem_tokens = _decode_tokens(sem.get("data", [])) if isinstance(sem, dict) else []
+    legend = response.get("result", {}).get("capabilities", {}) \
+        .get("semanticTokensProvider", {}).get("legend", {}).get("tokenTypes", [])
+    function_type = legend.index("function")
+    functions = {(t["line"], t["character"]) for t in sem_tokens if t["type"] == function_type}
+    if (0, 4) not in functions or (3, 4) not in functions:
+        raise AssertionError(f"semantic tokens lost after a lexer error: {sem_tokens}")
+    client.notify("textDocument/didClose", {"textDocument": {"uri": uri}})
+    client.wait_notification("textDocument/publishDiagnostics")
+
     client.request("shutdown")
     code = client.close()
     if code != 0:
         raise AssertionError(f"exit code is {code}, expected 0")
+
+    # A pull-diagnostics client must not also receive publishDiagnostics (that shows every
+    # problem twice in the Problems panel).
+    pull_client = Client(exe)
+    pull_client.request(
+        "initialize",
+        {"processId": os.getpid(), "rootUri": root.as_uri(),
+         "capabilities": {"textDocument": {"diagnostic": {}}}},
+    )
+    pull_client.notify("initialized", {})
+    pull_client.notify(
+        "textDocument/didOpen",
+        {"textDocument": {"uri": uri, "languageId": "viper", "version": 4, "text": overflow}},
+    )
+    time.sleep(0.4)
+    pushed: list[dict[str, Any]] = []
+    while not pull_client.reader.messages.empty():
+        pushed.append(pull_client.reader.messages.get())
+    if any(m.get("method") == "textDocument/publishDiagnostics" for m in pushed):
+        raise AssertionError(f"pull client received duplicate push diagnostics: {pushed}")
+    pulled = pull_client.request(
+        "textDocument/diagnostic", {"textDocument": {"uri": uri}}, timeout=60.0
+    ).get("result")
+    items = pulled.get("items", []) if isinstance(pulled, dict) else []
+    if len(items) != 1:
+        raise AssertionError(f"pull diagnostics returned {len(items)} items: {pulled}")
+    pull_client.request("shutdown")
+    pull_client.close()
+
     print("diagnostics: OK")
     print("recovery: OK")
+    print("overflow-diagnostics: OK")
     return 0