ClangCodeModel: Fix another false positive

... in output argument highlighting.
If there is not enough information for clang to determine the const-ness
of the argument passing (as it can happen in templates), do not report
an output argument.

Change-Id: I8d0143042f02ac44d8d971398014828cff14697f
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/clangcodemodel/clangdclient.cpp

@@ -2712,8 +2712,12 @@ static void semanticHighlighter(QFutureInterface<HighlightingResult> &future,
             if (it->kind() == "Call") {
                 // The first child is e.g. a called lambda or an object on which
                 // the call happens, and should not be highlighted as an output argument.
+                // If the call is not fully resolved (as in templates), we don't
+                // know whether the argument is passed as const or not.
                 const QList<AstNode> children = it->children().value_or(QList<AstNode>());
-                return children.isEmpty() || children.first().range() != (it - 1)->range();
+                return children.isEmpty()
+                        || (children.first().range() != (it - 1)->range()
+                                && children.first().kind() != "UnresolvedLookup");
             }
 
             // The token should get marked for e.g. lambdas, but not for assignment operators,

src/plugins/clangcodemodel/test/clangdtests.cpp

@@ -1327,6 +1327,8 @@ void ClangdTestHighlighting::test_data()
                                                   << QList<int>{C_LOCAL} << 0;
     QTest::newRow("call on inherited member") << 1024 << 9 << 1024 << 12
                                                   << QList<int>{C_FIELD} << 0;
+    QTest::newRow("pass inherited member by value") << 1038 << 21 << 1038 << 26
+                                                    << QList<int>{C_FIELD} << 0;
 }
 
 void ClangdTestHighlighting::test()

src/plugins/clangcodemodel/test/data/highlighting/highlighting.cpp

@@ -1024,3 +1024,19 @@ template<typename T> class Derived : public BaseWithMember
         vec.clear();
     }
 };
+
+static bool testVal(int val);
+class BaseWithMember2
+{
+protected:
+    int value;
+};
+template<typename T> class Derived2 : public BaseWithMember2
+{
+    bool foo()
+    {
+        if (testVal(value))
+            return true;
+        return false;
+    }
+};