#3467 lsp: show log output as debug log

Signed-off-by: Patrizio Bekerle <patrizio@bekerle.com>

Author: pbek

CHANGELOG.md

@@ -16,6 +16,19 @@
   was called synchronously, causing a SIGSEGV in QtWidgets; the UI update is now
   deferred via `QTimer::singleShot` so it runs after the current event is fully
   processed (for [#3578](https://github.com/pbek/QOwnNotes/issues/3578))
+- All Markdown LSP server stderr output is now forwarded to the debug log
+  (via `qDebug`) so the full server log is visible when running QOwnNotes
+  with debug output enabled; previously only lines containing `ERR`/`ERROR`
+  were forwarded (for [#3467](https://github.com/pbek/QOwnNotes/issues/3467))
+- Added debug logging when `textDocument/publishDiagnostics` notifications
+  are received from the Markdown LSP server and when they are applied to the
+  note text edit, to help diagnose why error markers may not appear; note that
+  `marksman` (the default LSP server) does not publish diagnostics — it
+  focuses on cross-reference and wiki-link completion only; to get real-time
+  wave-underline error markers in the note editor, configure a linting LSP
+  such as `rumdl` (command: `rumdl`, argument: `server`) which provides 71
+  Markdown lint rules and publishes `textDocument/publishDiagnostics`
+  (for [#3467](https://github.com/pbek/QOwnNotes/issues/3467))
 
 ## 26.4.22
 

src/services/markdownlspclient.cpp

@@ -427,6 +427,8 @@ void MarkdownLspClient::onReadyReadStandardError() {
             if (trimmed.isEmpty()) {
                 continue;
             }
+            // Log all stderr output as debug for diagnostics
+            qDebug() << "Markdown LSP server:" << trimmed;
             if (errorPattern.match(trimmed).hasMatch()) {
                 emit errorMessage(trimmed);
             }
@@ -625,6 +627,7 @@ void MarkdownLspClient::handleNotification(const QJsonObject &object) {
         diagnostics.push_back(diagnostic);
     }
 
+    qDebug() << "Markdown LSP diagnostics received for" << uri << "- count:" << diagnostics.size();
     emit diagnosticsReceived(uri, diagnostics);
 }
 

src/widgets/qownnotesmarkdowntextedit.cpp

@@ -3598,9 +3598,12 @@ void QOwnNotesMarkdownTextEdit::showMarkdownLspCompletions(int requestId,
 void QOwnNotesMarkdownTextEdit::showMarkdownLspDiagnostics(
     const QString &uri, const QVector<MarkdownLspClient::Diagnostic> &diagnostics) {
     if (uri != _markdownLspUri) {
+        qDebug() << "Markdown LSP: ignoring diagnostics for" << uri
+                 << "(current:" << _markdownLspUri << ")";
         return;
     }
 
+    qDebug() << "Markdown LSP: applying" << diagnostics.size() << "diagnostics for" << uri;
     _markdownLspDiagnostics = diagnostics;
     _markdownLspDiagnosticsSelections.clear();
     for (const MarkdownLspClient::Diagnostic &diagnostic : diagnostics) {