Fix #12487 FN knownConditionTrueFalse with integer operand (#6082)

Author: chrchr-github

lib/checkcondition.cpp

@@ -1540,9 +1540,17 @@ void CheckCondition::alwaysTrueFalse()
                 continue;
             if (Token::Match(tok, "! %num%|%bool%|%char%"))
                 continue;
-            if (Token::Match(tok, "%oror%|&&") &&
-                (tok->astOperand1()->hasKnownIntValue() || tok->astOperand2()->hasKnownIntValue()))
-                continue;
+            if (Token::Match(tok, "%oror%|&&")) {
+                bool bail = false;
+                for (const Token* op : { tok->astOperand1(), tok->astOperand2() }) {
+                    if (op->hasKnownIntValue() && (!op->isLiteral() || op->isBoolean())) {
+                        bail = true;
+                        break;
+                    }
+                }
+                if (bail)
+                    continue;
+            }
             if (Token::simpleMatch(tok, ":"))
                 continue;
             if (Token::Match(tok->astOperand1(), "%name% (") && Token::simpleMatch(tok->astParent(), "return"))

test/testcondition.cpp

@@ -5712,6 +5712,13 @@ class TestCondition : public TestFixture {
               "        return s.size()>2U && s[0]=='4' && s[0]=='2';\n"
               "}\n");
         ASSERT_EQUALS("[test.cpp:2] -> [test.cpp:2]: (style) Return value 's[0]=='2'' is always false\n", errout.str());
+
+        check("void f(int i) { if (i == 1 || 2) {} }\n"); // #12487
+        ASSERT_EQUALS("[test.cpp:1]: (style) Condition 'i==1||2' is always true\n", errout.str());
+
+        check("enum E { E1 = 1, E2 = 2 };\n"
+              "void f(int i) { if (i == E1 || E2) {} }\n");
+        ASSERT_EQUALS("[test.cpp:2]: (style) Condition 'i==E1||E2' is always true\n", errout.str());
     }
 
     void pointerAdditionResultNotNull() {