portable_storage: forbid unnamed sections

contrib/epee/include/storages/portable_storage.h

@@ -266,6 +266,7 @@ namespace epee
       static_assert(std::is_rvalue_reference<entry_type&&>(), "unexpected copy of value");
       TRY_ENTRY();
       CHECK_AND_ASSERT(psection, nullptr);
+      CHECK_AND_ASSERT(!pentry_name.empty(), nullptr);
       auto ins_res = psection->m_entries.emplace(pentry_name, std::forward<entry_type>(entry));
       return &ins_res.first->second;
       CATCH_ENTRY("portable_storage::insert_new_entry_get_storage_entry", nullptr);

contrib/epee/include/storages/portable_storage_from_bin.h

@@ -108,6 +108,7 @@ namespace epee
       RECURSION_LIMITATION();
       uint8_t name_len = 0;
       read(name_len);
+      CHECK_AND_ASSERT_THROW_MES(name_len > 0, "Section name is missing");
       sce_name.resize(name_len);
       read((void*)sce_name.data(), name_len);
     }

contrib/epee/include/storages/portable_storage_to_bin.h

@@ -211,6 +211,7 @@ namespace epee
       for(const section_pair& se: sec.m_entries)
       {
         CHECK_AND_ASSERT_THROW_MES(se.first.size() < std::numeric_limits<uint8_t>::max(), "storage_entry_name is too long: " << se.first.size() << ", val: " << se.first);
+        CHECK_AND_ASSERT_THROW_MES(!se.first.empty(), "storage_entry_name is empty");
         uint8_t len = static_cast<uint8_t>(se.first.size());
         strm.write((const char*)&len, sizeof(len));
         strm.write(se.first.data(), size_t(len));