Fixed #7310 (ValueFlow: Value of NULL in function call)

Author: danmar

lib/valueflow.cpp

@@ -584,6 +584,12 @@ static void valueFlowNumber(TokenList *tokenlist)
                 ValueFlow::Value value(tok->str() == "true");
                 value.setKnown();
                 setTokenValue(tok, value);
+            } else if (Token::Match(tok, "[(,] NULL [,)]")) {
+                // NULL function parameters are not simplified in the
+                // normal tokenlist
+                ValueFlow::Value value(0);
+                value.setKnown();
+                setTokenValue(tok->next(), value);
             }
         }
     }

test/testvalueflow.cpp

@@ -167,6 +167,7 @@ class TestValueFlow : public TestFixture {
         ASSERT_EQUALS(123, valueOfTok("x=123;",   "123").intvalue);
         ASSERT_EQUALS(0, valueOfTok("x=false;", "false").intvalue);
         ASSERT_EQUALS(1, valueOfTok("x=true;",  "true").intvalue);
+        ASSERT_EQUALS(0, valueOfTok("x(NULL);",  "NULL").intvalue);
         ASSERT_EQUALS((int)('a'), valueOfTok("x='a';",  "'a'").intvalue);
         ASSERT_EQUALS((int)('\n'), valueOfTok("x='\\n';", "'\\n'").intvalue);
     }