Fix issue 8839: FP knownConditionTrueFalse - condition inside a while-clause (#1469)

lib/valueflow.cpp

@@ -1145,6 +1145,7 @@ static void valueFlowTerminatingCondition(TokenList *tokenlist, SymbolDatabase*
             const Scope * condScope = nullptr;
             for(const Scope * parent = condTok->scope();parent;parent = parent->nestedIn) {
                 if (parent->type == Scope::eIf || 
+                    parent->type == Scope::eWhile ||
                     parent->type == Scope::eSwitch) {
                     condScope = parent;
                     break;

test/testcondition.cpp

@@ -2673,6 +2673,16 @@ private:
               "    return std::time(0) > maxtime;\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        check("void foo(double param) {\n"
+              "  while(bar()) {\n"
+              "    if (param<0.)\n"
+              "       return;\n"
+              "  }\n"
+              "  if (param<0.)\n"
+              "    return;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void multiConditionAlwaysTrue() {