Fix crash in iscpp11init_impl() (#4743)

Author: chrchr-github

lib/tokenlist.cpp

@@ -677,7 +677,7 @@ static bool iscpp11init_impl(const Token * const tok)
         return false; // trailing return type. The only function body that can contain no semicolon is a void function.
     if (Token::simpleMatch(nameToken->previous(), "namespace") || Token::simpleMatch(nameToken, "namespace") /*anonymous namespace*/)
         return false;
-    if (endtok != nullptr && !Token::Match(nameToken, "return|:")) {
+    if (precedes(nameToken->next(), endtok) && !Token::Match(nameToken, "return|:")) {
         // If there is semicolon between {..} this is not a initlist
         for (const Token *tok2 = nameToken->next(); tok2 != endtok; tok2 = tok2->next()) {
             if (tok2->str() == ";")

test/testtokenize.cpp

@@ -7654,6 +7654,9 @@ class TestTokenizer : public TestFixture {
                         "};\n",
                         "{ } }",
                         TokenImpl::Cpp11init::NOINIT);
+
+        ASSERT_NO_THROW(tokenizeAndStringify("template<typename U> struct X {};\n" // don't crash
+                                             "template<typename T> auto f(T t) -> X<decltype(t + 1)> {}\n"));
         #undef testIsCpp11init
     }
 };