Fix issue 9865: false positive: knownConditionTrueFalse (cppcheck-opensource#2764)

pfultz2 · web-flow · commit ba84196dca10 · 2020-09-01T11:22:38.000+02:00
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
@@ -4325,6 +4325,8 @@ struct ValueFlowConditionHandler {
                         if (!values.empty()) {
                             bool assign = false;
                             visitAstNodes(parent->astOperand2(), [&](Token* tok2) {
+                                if (tok2 == tok)
+                                    return ChildrenToVisit::done;
                                 if (isSameExpression(tokenlist->isCPP(), false, cond.vartok, tok2, settings->library, true, false))
                                     setTokenValue(tok2, values.front(), settings);
                                 else if (Token::Match(tok2, "++|--|=") && isSameExpression(tokenlist->isCPP(),
diff --git a/test/testcondition.cpp b/test/testcondition.cpp
@@ -3412,6 +3412,18 @@ class TestCondition : public TestFixture {
               "}\n");
         ASSERT_EQUALS("", errout.str());
 
+        // #9865
+        check("void f(const std::string &s) {\n"
+              "    for (std::string::const_iterator it = s.begin(); it != s.end(); ++it) {\n"
+              "        const unsigned char c = static_cast<unsigned char>(*it);\n"
+              "        if (c == '0') {}\n"
+              "        else if ((c == 'a' || c == 'A')\n"
+              "                 || (c == 'b' || c == 'B')) {}\n"
+              "        else {}\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
     }
 
     void alwaysTrueInfer() {
