Fix 10318: iterator converted to type, wrong scope check (#3433)

lib/valueflow.cpp

@@ -3253,7 +3253,7 @@ static void valueFlowForwardLifetime(Token * tok, TokenList *tokenlist, ErrorLog
         return;
     }
     Token *parent = tok->astParent();
-    while (parent && (parent->isArithmeticalOp() || parent->str() == ","))
+    while (parent && parent->str() == ",")
         parent = parent->astParent();
     if (!parent)
         return;

test/testautovariables.cpp

@@ -2421,6 +2421,17 @@ private:
               "    }\n"
               "};\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("int f() {\n"
+              "    int i;\n"
+              "    {\n"
+              "        std::vector<int> vec;\n"
+              "        const auto iter = vec.begin();\n"
+              "        i = (int)(iter - vec.begin());\n"
+              "    }\n"
+              "    return i;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void danglingLifetime() {