Fix #13450 FP containerOutOfBounds with nested std::vector (danmar#7118)

Author: chrchr-github

lib/valueflow.cpp

@@ -6428,9 +6428,9 @@ static std::vector<ValueFlow::Value> getInitListSize(const Token* tok,
     std::vector<const Token*> args = getArguments(tok);
     if (args.empty())
         return {makeContainerSizeValue(std::size_t{0}, known)};
-    bool initList = true;
+    bool initList = tok->str() == "{";
     // Try to disambiguate init list from constructor
-    if (args.size() < 4) {
+    if (initList && args.size() < 4) {
         initList = !isIteratorPair(args);
         const Token* containerTypeToken = valueType->containerTypeToken;
         if (valueType->container->stdStringLike) {

test/testvalueflow.cpp

@@ -7121,6 +7121,12 @@ class TestValueFlow : public TestFixture {
                "    return x;\n"
                "}";
         ASSERT_EQUALS(false, testValueOfXKnown(code, 5U, 2));
+
+        code = "auto f() {\n" // #13450
+               "    auto v = std::vector<std::vector<S*>>(3, std::vector<S*>());\n"
+               "    return v[2];\n"
+               "}";
+        ASSERT(isKnownContainerSizeValue(tokenValues(code, "v ["), 3).empty());
     }
 
     void valueFlowContainerElement()