ClangCodeModel: Fix mis-detection of class members as operators

The name check was not tight enough.

Change-Id: I5d813a29525bd5b5c23ce04f0bd9e5982a36536e
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/clangcodemodel/clangdclient.cpp

@@ -3839,10 +3839,18 @@ void ExtraHighlightingResultsCollector::collectFromNode(const AstNode &node)
     QString detail = node.detail().value_or(QString());
     const bool isCallToNew = node.kind() == "CXXNew";
     const bool isCallToDelete = node.kind() == "CXXDelete";
-    if (!isCallToNew && !isCallToDelete
+    const auto isProperOperator = [&] {
-            && (!detail.startsWith(operatorPrefix) || detail == operatorPrefix)) {
+        if (isCallToNew || isCallToDelete)
+            return true;
+        if (!detail.startsWith(operatorPrefix))
+            return false;
+        if (detail == operatorPrefix)
+            return false;
+        const QChar nextChar = detail.at(operatorPrefix.length());
+        return !nextChar.isLetterOrNumber() && nextChar != '_';
+    };
+    if (!isProperOperator())
         return;
-    }
 
     if (!isCallToNew && !isCallToDelete)
         detail.remove(0, operatorPrefix.length());

src/plugins/clangcodemodel/test/clangdtests.cpp

@@ -1329,6 +1329,14 @@ void ClangdTestHighlighting::test_data()
                                                   << QList<int>{C_FIELD} << 0;
     QTest::newRow("pass inherited member by value") << 1038 << 21 << 1038 << 26
                                                     << QList<int>{C_FIELD} << 0;
+    QTest::newRow("fake operator member declaration") << 1045 << 9 << 1045 << 23
+                                                    << QList<int>{C_FIELD, C_DECLARATION} << 0;
+    QTest::newRow("fake operator method declaration") << 1046 << 10 << 1046 << 24
+                                                    << QList<int>{C_FUNCTION, C_DECLARATION} << 0;
+    QTest::newRow("fake operator member access") << 1049 << 8 << 1049 << 22
+                                                    << QList<int>{C_FIELD} << 0;
+    QTest::newRow("fake operator method call") << 1050 << 8 << 1050 << 22
+                                               << QList<int>{C_FUNCTION} << 0;
 }
 
 void ClangdTestHighlighting::test()

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

@@ -1040,3 +1040,12 @@ template<typename T> class Derived2 : public BaseWithMember2
         return false;
     }
 };
+
+struct StructWithMisleadingMemberNames {
+    int operatormember;
+    void operatorMethod();
+};
+void useStrangeStruct(StructWithMisleadingMemberNames *s) {
+    s->operatormember = 5;
+    s->operatorMethod();
+}