Fix 10468: False positive; uninitialized variable. Loop is always executed at least once (#3462)

Author: pfultz2

lib/forwardanalyzer.cpp

@@ -67,7 +67,7 @@ struct ForwardTraversal {
         std::vector<int> result = analyzer->evaluate(tok, ctx);
         // TODO: We should convert to bool
         bool checkThen = std::any_of(result.begin(), result.end(), [](int x) {
-            return x == 1;
+            return x != 0;
         });
         bool checkElse = std::any_of(result.begin(), result.end(), [](int x) {
             return x == 0;

lib/valueflow.cpp

@@ -705,6 +705,7 @@ static void setTokenValue(Token* tok, ValueFlow::Value value, const Settings* se
             }
         } else if (!value.isImpossible()) {
             // is condition only depending on 1 variable?
+            // cppcheck-suppress[variableScope] #8541
             nonneg int varId = 0;
             bool ret = false;
             visitAstNodes(parent->astOperand1(),
@@ -724,9 +725,6 @@ static void setTokenValue(Token* tok, ValueFlow::Value value, const Settings* se
             v.conditional = true;
             v.changeKnownToPossible();
 
-            if (varId)
-                v.varId = varId;
-
             setTokenValue(parent, v, settings);
         }
     }

test/testuninitvar.cpp

@@ -4895,6 +4895,15 @@ class TestUninitVar : public TestFixture {
                         "  return a;\n" // <- a has been initialized
                         "}");
         ASSERT_EQUALS("[test.cpp:3]: (error) Uninitialized variable: x\n", errout.str());
+
+        // #10468
+        valueFlowUninit("uint32_t foo(uint32_t in) {\n"
+                        "    uint32_t out, mask = 0x7F;\n"
+                        "    while (mask ^ 0x7FFFFFFF)\n"
+                        "        out = in & ~mask;\n"
+                        "    return out;\n"
+                        "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void uninitvar_ipa() {