ValueFlow: Better handling of && and || in for loop to avoid FP

Author: danmar

lib/valueflow.cpp

@@ -2301,8 +2301,8 @@ static void valueFlowForLoopSimplify(Token * const bodyStart, const unsigned int
 
         if (Token::Match(tok2, "%oror%|&&")) {
             const ProgramMemory programMemory(getProgramMemory(tok2->astTop(), varid, ValueFlow::Value(value)));
-            if ((tok2->str() == "&&" && conditionIsFalse(tok2->astOperand1(), programMemory)) ||
-                (tok2->str() == "||" && conditionIsTrue(tok2->astOperand1(), programMemory))) {
+            if ((tok2->str() == "&&" && !conditionIsTrue(tok2->astOperand1(), programMemory)) ||
+                (tok2->str() == "||" && !conditionIsFalse(tok2->astOperand1(), programMemory))) {
                 // Skip second expression..
                 const Token *parent = tok2;
                 while (parent && parent->str() == tok2->str())

test/testvalueflow.cpp

@@ -1731,6 +1731,14 @@ class TestValueFlow : public TestFixture {
         ASSERT_EQUALS(false, testValueOfX(code, 4U, 0));
         ASSERT_EQUALS(true,  testValueOfX(code, 4U, 9));
 
+        code = "void foo() {\n"
+               "  for (int x = 0; x < 10; x++) {\n"
+               "    if (x < value\n"
+               "        && x) {}" // <- maybe x is not 9
+               "  }\n"
+               "}\n";
+        ASSERT_EQUALS(false, testValueOfX(code, 4U, 9));
+
         // ||
         code = "void foo() {\n"
                "  for (int x = 0; x < 10; x++) {\n"