From b9af9881a9024732e738f05fbaa7375f69eb47e5 Mon Sep 17 00:00:00 2001
From: David Schulz <david.schulz@qt.io>
Date: Mon, 17 Feb 2020 12:57:59 +0100
Subject: [PATCH] LanguageClient: update semantic highlighting only if server
 supports it

Task-number: QTCREATORBUG-23599
Change-Id: I76c804b51362ad6ab2aecf0631a16289a33e4810
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
---
 src/plugins/languageclient/client.cpp                  |  6 ++++--
 .../languageclient/semantichighlightsupport.cpp        | 10 ++++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/plugins/languageclient/client.cpp b/src/plugins/languageclient/client.cpp
index cafad5f89cc..5d62cdfeb9a 100644
--- a/src/plugins/languageclient/client.cpp
+++ b/src/plugins/languageclient/client.cpp
@@ -392,8 +392,10 @@ void Client::deactivateDocument(TextEditor::TextDocument *document)
     hideDiagnostics(document);
     resetAssistProviders(document);
     document->setFormatter(nullptr);
-    if (TextEditor::SyntaxHighlighter *highlighter = document->syntaxHighlighter())
-        highlighter->clearAllExtraFormats();
+    if (m_serverCapabilities.semanticHighlighting().has_value()) {
+        if (TextEditor::SyntaxHighlighter *highlighter = document->syntaxHighlighter())
+            highlighter->clearAllExtraFormats();
+    }
     for (Core::IEditor *editor : Core::DocumentModel::editorsForDocument(document)) {
         if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor))
             textEditor->editorWidget()->removeHoverHandler(&m_hoverHandler);
diff --git a/src/plugins/languageclient/semantichighlightsupport.cpp b/src/plugins/languageclient/semantichighlightsupport.cpp
index 59b415455f7..8f333ea1838 100644
--- a/src/plugins/languageclient/semantichighlightsupport.cpp
+++ b/src/plugins/languageclient/semantichighlightsupport.cpp
@@ -151,10 +151,12 @@ void applyHighlight(TextEditor::TextDocument *doc,
         }
     }
 
-    TextEditor::SemanticHighlighter::setExtraAdditionalFormats(
-        doc->syntaxHighlighter(),
-        results,
-        scopesToFormatHash(highlightScopes(capabilities), doc->fontSettings()));
+    if (capabilities.semanticHighlighting().has_value()) {
+        TextEditor::SemanticHighlighter::setExtraAdditionalFormats(
+            doc->syntaxHighlighter(),
+            results,
+            scopesToFormatHash(highlightScopes(capabilities), doc->fontSettings()));
+    }
 }
 
 } // namespace SemanticHighligtingSupport