Language protocol: no longer show completion window when no completion items match completion prefix in source buffer

src/source_language_protocol.cc

@@ -1414,6 +1414,12 @@ void Source::LanguageProtocolView::setup_autocomplete() {
                 }
               }
               if(!label.empty()) {
+                std::string prefix;
+                {
+                  std::lock_guard<std::mutex> lock(autocomplete.prefix_mutex);
+                  prefix = autocomplete.prefix;
+                }
+                if(prefix.compare(0, prefix.size(), label, 0, prefix.size()) == 0) {
                   autocomplete.rows.emplace_back(std::move(label));
                   autocomplete_comment.emplace_back(std::move(detail));
                   if(!documentation.empty() && documentation != autocomplete_comment.back()) {
@@ -1424,6 +1430,7 @@ void Source::LanguageProtocolView::setup_autocomplete() {
                   autocomplete_insert.emplace_back(std::move(insert));
                 }
               }
+            }
 
             if(autocomplete_enable_snippets) {
               std::string prefix;