Fix #12641 FP mismatchingContainers with repeated ternary (#6337)

Author: chrchr-github

lib/checkstl.cpp

@@ -727,12 +727,18 @@ static bool isSameIteratorContainerExpression(const Token* tok1,
 
 static ValueFlow::Value getLifetimeIteratorValue(const Token* tok, MathLib::bigint path = 0)
 {
+    auto findIterVal = [](const std::vector<ValueFlow::Value>& values, const std::vector<ValueFlow::Value>::const_iterator beg) {
+        return std::find_if(beg, values.cend(), [](const ValueFlow::Value& v) {
+            return v.lifetimeKind == ValueFlow::Value::LifetimeKind::Iterator;
+        });
+    };
     std::vector<ValueFlow::Value> values = ValueFlow::getLifetimeObjValues(tok, false, path);
-    auto it = std::find_if(values.cbegin(), values.cend(), [](const ValueFlow::Value& v) {
-        return v.lifetimeKind == ValueFlow::Value::LifetimeKind::Iterator;
-    });
-    if (it != values.end())
-        return *it;
+    auto it = findIterVal(values, values.begin());
+    if (it != values.end()) {
+        auto it2 = findIterVal(values, it + 1);
+        if (it2 == values.cend())
+            return *it;
+    }
     if (values.size() == 1)
         return values.front();
     return ValueFlow::Value{};

test/teststl.cpp

@@ -69,6 +69,7 @@ class TestStl : public TestFixture {
         TEST_CASE(iterator27); // #10378
         TEST_CASE(iterator28); // #10450
         TEST_CASE(iterator29);
+        TEST_CASE(iterator30);
         TEST_CASE(iteratorExpression);
         TEST_CASE(iteratorSameExpression);
         TEST_CASE(mismatchingContainerIterator);
@@ -1869,6 +1870,22 @@ class TestStl : public TestFixture {
         ASSERT_EQUALS("", errout_str());
     }
 
+    void iterator30()
+    {
+        check("struct S {\n" // #12641
+              "    bool b;\n"
+              "    std::list<int> A, B;\n"
+              "    void f();\n"
+              "};\n"
+              "void S::f() {\n"
+              "    std::list<int>::iterator i = (b ? B : A).begin();\n"
+              "    while (i != (b ? B : A).end()) {\n"
+              "        ++i;\n"
+              "    }\n"
+              "}\n");
+        ASSERT_EQUALS("", errout_str());
+    }
+
     void iteratorExpression() {
         check("std::vector<int>& f();\n"
               "std::vector<int>& g();\n"