Fix crash in CheckLeakAutoVar (f'up to #12186) (#5683)

Author: chrchr-github

lib/checkleakautovar.cpp

@@ -1109,8 +1109,8 @@ void CheckLeakAutoVar::ret(const Token *tok, VarInfo &varInfo, const bool isEndO
             }
 
             // don't warn when returning after checking return value of outparam allocation
-            const Scope* scope = tok->scope();
-            if (scope->type == Scope::ScopeType::eIf || scope->type== Scope::ScopeType::eElse) {
+            if (it->second.allocTok && (tok->scope()->type == Scope::ScopeType::eIf || tok->scope()->type== Scope::ScopeType::eElse)) {
+                const Scope* scope = tok->scope();
                 if (scope->type == Scope::ScopeType::eElse) {
                     scope = scope->bodyStart->tokAt(-2)->scope();
                 }

test/testleakautovar.cpp

@@ -1594,6 +1594,16 @@ class TestLeakAutoVar : public TestFixture {
               "    s->p = NULL;\n"
               "}\n");
         ASSERT_EQUALS("", errout.str());
+
+        const Settings s = settingsBuilder().library("std.cfg").build();
+        check("struct S {};\n"
+              "void f(int i, std::vector<std::unique_ptr<S>> &v) {\n"
+              "    if (i < 1) {\n"
+              "        auto s = new S;\n"
+              "        v.push_back(std::unique_ptr<S>(s));\n"
+              "    }\n"
+              "}\n", &s);
+        ASSERT_EQUALS("", errout.str()); // don't crash
     }
 
     void goto1() {