LanguageClient: prevent assert in semantic highlighter

Do not send messages to server that are not reachable, but queue the
highlighting requests until the client is fully initialized.

Change-Id: I7da140ec33fb1974d3eaed03110ed85dc3a87594
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/languageclient/semantichighlightsupport.cpp

@@ -68,12 +68,16 @@ void SemanticTokenSupport::refresh()
 
 void SemanticTokenSupport::reloadSemanticTokens(TextDocument *textDocument)
 {
-    reloadSemanticTokensImpl(textDocument);
+    if (m_client->reachable())
+        reloadSemanticTokensImpl(textDocument);
+    else
+        queueDocumentReload(textDocument);
 }
 
 void SemanticTokenSupport::reloadSemanticTokensImpl(TextDocument *textDocument,
                                                     int remainingRerequests)
 {
+    m_docReloadQueue.remove(textDocument);
     const SemanticRequestTypes supportedRequests = supportedSemanticRequests(textDocument);
     if (supportedRequests.testFlag(SemanticRequestType::None))
         return;
@@ -122,7 +126,10 @@ void SemanticTokenSupport::reloadSemanticTokensImpl(TextDocument *textDocument,
 
 void SemanticTokenSupport::updateSemanticTokens(TextDocument *textDocument)
 {
-    updateSemanticTokensImpl(textDocument);
+    if (m_client->reachable())
+        updateSemanticTokensImpl(textDocument);
+    else
+        queueDocumentReload(textDocument);
 }
 
 void SemanticTokenSupport::updateSemanticTokensImpl(TextDocument *textDocument,
@@ -168,6 +175,22 @@ void SemanticTokenSupport::updateSemanticTokensImpl(TextDocument *textDocument,
     reloadSemanticTokens(textDocument);
 }
 
+void SemanticTokenSupport::queueDocumentReload(TextEditor::TextDocument *doc)
+{
+    if (m_docReloadQueue.contains(doc))
+        return;
+    m_docReloadQueue << doc;
+    connect(
+        m_client,
+        &Client::initialized,
+        this,
+        [this, doc = QPointer<TextDocument>(doc)]() {
+            if (doc)
+                reloadSemanticTokensImpl(doc);
+        },
+        Qt::QueuedConnection);
+}
+
 void SemanticTokenSupport::clearHighlight(TextEditor::TextDocument *doc)
 {
     if (m_tokens.contains(doc->filePath())){

src/plugins/languageclient/semantichighlightsupport.h

@@ -32,6 +32,7 @@
 #include <texteditor/semantichighlighter.h>
 #include <texteditor/textdocument.h>
 
+#include <QSet>
 #include <QTextCharFormat>
 
 #include <functional>
@@ -86,6 +87,7 @@ public:
 private:
     void reloadSemanticTokensImpl(TextEditor::TextDocument *doc, int remainingRerequests = 3);
     void updateSemanticTokensImpl(TextEditor::TextDocument *doc, int remainingRerequests = 3);
+    void queueDocumentReload(TextEditor::TextDocument *doc);
     LanguageServerProtocol::SemanticRequestTypes supportedSemanticRequests(
         TextEditor::TextDocument *document) const;
     void handleSemanticTokens(const Utils::FilePath &filePath,
@@ -117,6 +119,7 @@ private:
     SemanticTokensHandler m_tokensHandler;
     QStringList m_tokenTypeStrings;
     QStringList m_tokenModifierStrings;
+    QSet<TextEditor::TextDocument *> m_docReloadQueue;
 };
 
 } // namespace LanguageClient