Fix #9789 FP Logical condition considered always false (#3985)

Author: chrchr-github

lib/checkcondition.cpp

@@ -1134,6 +1134,11 @@ void CheckCondition::checkIncorrectLogicOperator()
             if (inconclusive && !printInconclusive)
                 continue;
 
+            const bool isUnknown = (expr1 && expr1->valueType() && expr1->valueType()->type == ValueType::UNKNOWN_TYPE) ||
+                                   (expr2 && expr2->valueType() && expr2->valueType()->type == ValueType::UNKNOWN_TYPE);
+            if (isUnknown)
+                continue;
+
             const bool isfloat = astIsFloat(expr1, true) || MathLib::isFloat(value1) || astIsFloat(expr2, true) || MathLib::isFloat(value2);
 
             ErrorPath errorPath;
@@ -1442,6 +1447,12 @@ void CheckCondition::alwaysTrueFalse()
             if (!(constIfWhileExpression || constValExpr || compExpr || ternaryExpression || returnExpression))
                 continue;
 
+            const Token* expr1 = tok->astOperand1(), *expr2 = tok->astOperand2();
+            const bool isUnknown = (expr1 && expr1->valueType() && expr1->valueType()->type == ValueType::UNKNOWN_TYPE) ||
+                                   (expr2 && expr2->valueType() && expr2->valueType()->type == ValueType::UNKNOWN_TYPE);
+            if (isUnknown)
+                continue;
+
             // Don't warn when there are expanded macros..
             bool isExpandedMacro = false;
             visitAstNodes(tok, [&](const Token * tok2) {

test/testcondition.cpp

@@ -1209,6 +1209,14 @@ class TestCondition : public TestFixture {
               "  if (x && x != ZERO) {}\n"
               "}");
         ASSERT_EQUALS("", errout.str());
+
+        check("void f(int N) {\n" // #9789
+              "    T a[20] = { 0 };\n"
+              "    for (int i = 0; i < N; ++i) {\n"
+              "        if (0 < a[i] && a[i] < 1) {}\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void incorrectLogicOperator5() { // complex expressions