Set failbit on ostream in case of error

4 files changed, 31 insertions, 2 deletions

diff --git a/src/io/stream_writer.cpp b/src/io/stream_writer.cpp
index ee8b0ee2b6..036c5d40ac 100644
--- a/src/io/stream_writer.cpp
+++ b/src/io/stream_writer.cpp
@@ -41,6 +41,7 @@ void stream_writer::write_string(const std::string& str)
 {
     if(str.size() > max_string_len)
     {
+        os.setstate(std::ios::failbit);
         std::ostringstream sstr;
         sstr << "String is too long for NBT (" << str.size() << " > " << max_string_len << ")";
         throw std::length_error(sstr.str());
diff --git a/src/tag_array.cpp b/src/tag_array.cpp
index 124c470bd1..41f00eedc3 100644
--- a/src/tag_array.cpp
+++ b/src/tag_array.cpp
@@ -147,7 +147,10 @@ template<>
 void tag_array<int8_t>::write_payload(io::stream_writer& writer) const
 {
     if(size() > INT32_MAX)
+    {
+        writer.get_ostr().setstate(std::ios::failbit);
         throw std::length_error("Byte array is too large for NBT");
+    }
     writer.write_num(static_cast<int32_t>(size()));
     writer.get_ostr().write(reinterpret_cast<const char*>(data.data()), data.size());
 }
@@ -156,7 +159,10 @@ template<>
 void tag_array<int32_t>::write_payload(io::stream_writer& writer) const
 {
     if(size() > INT32_MAX)
+    {
+        writer.get_ostr().setstate(std::ios::failbit);
         throw std::length_error("Int array is too large for NBT");
+    }
     writer.write_num(static_cast<int32_t>(size()));
     for(int32_t i: data)
         writer.write_num(i);
diff --git a/src/tag_list.cpp b/src/tag_list.cpp
index dbdda2db77..d2aa01d314 100644
--- a/src/tag_list.cpp
+++ b/src/tag_list.cpp
@@ -162,7 +162,10 @@ void tag_list::read_payload(io::stream_reader& reader)
 void tag_list::write_payload(io::stream_writer& writer) const
 {
     if(size() > INT32_MAX)
+    {
+        writer.get_ostr().setstate(std::ios::failbit);
         throw std::length_error("List is too large for NBT");
+    }
     writer.write_type(el_type_ != tag_type::Null
                       ? el_type_
                       : tag_type::End);
@@ -171,7 +174,10 @@ void tag_list::write_payload(io::stream_writer& writer) const
     {
         //check if the value is of the correct type
         if(val.get_type() != el_type_)
+        {
+            writer.get_ostr().setstate(std::ios::failbit);
             throw std::bad_cast();
+        }
         writer.write_payload(val);
     }
 }
diff --git a/test/write_test.cpp b/test/write_test.cpp
index d6eac53a53..9445e4ab70 100644
--- a/test/write_test.cpp
+++ b/test/write_test.cpp
@@ -54,8 +54,11 @@ void test_stream_writer_big()
         0x00, 0x06, //string length in Big Endian
         'f', 'o', 'o', 'b', 'a', 'r'
     };
-    std::string s = os.str();
     ASSERT(os.str() == expected);
+
+    //too long for NBT
+    EXPECT_EXCEPTION(writer.write_string(std::string(65536, '.')), std::length_error);
+    ASSERT(!os);
     std::clog << "test_stream_writer_big passed" << std::endl;
 }
 
@@ -77,8 +80,10 @@ void test_stream_writer_little()
         0x06, 0x00, //string length in Little Endian
         'f', 'o', 'o', 'b', 'a', 'r'
     };
-    std::string s = os.str();
     ASSERT(os.str() == expected);
+
+    EXPECT_EXCEPTION(writer.write_string(std::string(65536, '.')), std::length_error);
+    ASSERT(!os);
     std::clog << "test_stream_writer_little passed" << std::endl;
 }
 
@@ -114,6 +119,9 @@ void test_write_payload_big()
         0x00, 0x06, //string length in Big Endian
         'b', 'a', 'r', 'b', 'a', 'z'
     }));
+    EXPECT_EXCEPTION(writer.write_payload(tag_string(std::string(65536, '.'))), std::length_error);
+    ASSERT(!os);
+    os.clear();
 
     //tag_byte_array
     os.str("");
@@ -193,7 +201,15 @@ void test_write_payload_big()
     ASSERT(os.str() == endtag + subtag1 + subtag2 + endtag
         || os.str() == endtag + subtag2 + subtag1 + endtag);
 
+    //Now for write_tag:
+    os.str("");
+    writer.write_tag("foo", tag_string("quux"));
+    ASSERT(os.str() == subtag1);
     ASSERT(os);
+
+    //too long key for NBT
+    EXPECT_EXCEPTION(writer.write_tag(std::string(65536, '.'), tag_long(-1)), std::length_error);
+    ASSERT(!os);
     std::clog << "test_write_payload_big passed" << std::endl;
 }