ValueFlow: Avoid FP when lambda is used

lib/valueflow.cpp

@@ -1882,6 +1882,8 @@ static bool valueFlowForward(Token * const               startToken,
         // TODO: handle lambda functions
         if (tok2->str() == "[" && findLambdaEndToken(tok2)) {
             Token *lambdaEndToken = const_cast<Token *>(findLambdaEndToken(tok2));
+            if (isVariableChanged(lambdaEndToken->link(), lambdaEndToken, varid, var->isGlobal(), settings, tokenlist->isCPP()))
+                return false;
             // Dont skip lambdas for lifetime values
             if (!std::all_of(values.begin(), values.end(), std::mem_fn(&ValueFlow::Value::isLifetimeValue))) {
                 tok2 = lambdaEndToken;

test/testvalueflow.cpp

@@ -1441,6 +1441,15 @@ private:
                "}\n";
         ASSERT_EQUALS(false, testValueOfX(code, 4U, 0));
 
+        code = "int f() {\n"
+               "    int x = 1;\n"
+               "    dostuff([&]() {\n"
+               "        x = y;\n"
+               "    });\n"
+               "    return x;\n"
+               "}\n";
+        ASSERT_EQUALS(false, testValueOfX(code, 6U, 1));
+
         // ?:
         code = "void f() {\n"
                "    int x = 8;\n"