value flow: improved handling of cast

lib/tokenize.cpp

@@ -3641,6 +3641,8 @@ bool Tokenizer::simplifyTokenList2()
 
     list.createAst();
 
+    ValueFlow::setValues(&list, _errorLogger, _settings);
+
     if (_settings->terminated())
         return false;
 

lib/valueflow.cpp

@@ -164,9 +164,15 @@ static void setTokenValue(Token* tok, const ValueFlow::Value &value)
         --it;
     }
 
-    // Calculations..
     Token *parent = const_cast<Token*>(tok->astParent());
-    if (parent && parent->isArithmeticalOp() && parent->astOperand1() && parent->astOperand2()) {
+
+    // Cast..
+    if (parent && parent->str() == "(" && tok == parent->link()->next()) {
+        setTokenValue(parent,value);
+    }
+
+    // Calculations..
+    else if (parent && parent->isArithmeticalOp() && parent->astOperand1() && parent->astOperand2()) {
         std::list<ValueFlow::Value>::const_iterator value1, value2;
         for (value1 = parent->astOperand1()->values.begin(); value1 != parent->astOperand1()->values.end(); ++value1) {
             for (value2 = parent->astOperand2()->values.begin(); value2 != parent->astOperand2()->values.end(); ++value2) {

test/testbufferoverrun.cpp

@@ -2063,6 +2063,12 @@ private:
               "    if (i==10) {}\n"
               "}");
         ASSERT_EQUALS("[test.cpp:3] -> [test.cpp:4]: (warning) Array 'str[3]' accessed at index 10, which is out of bounds. Otherwise condition 'i==10' is redundant.\n", errout.str());
+
+        check("void f() {\n"
+              "    char str[3];\n"
+              "    str[((unsigned char)3) - 1] = 0;\n"
+              "}", false, "test.cpp", false);
+        ASSERT_EQUALS("", errout.str());
     }
 
     void buffer_overrun_1_standard_functions() {