2 files changed, 19 insertions, 3 deletions
diff --git a/src/utility/filteredStream.cpp b/src/utility/filteredStream.cpp
index eda0c64c..5db01047 100644
--- a/src/utility/filteredStream.cpp
+++ b/src/utility/filteredStream.cpp
@@ -30,6 +30,22 @@ namespace vmime {
 namespace utility {
 
 
+// filteredInputStream
+
+stream::size_type filteredInputStream::getBlockSize()
+{
+	return std::min(inputStream::getBlockSize(), getPreviousInputStream().getBlockSize());
+}
+
+
+// filteredOutputStream
+
+stream::size_type filteredOutputStream::getBlockSize()
+{
+	return std::min(outputStream::getBlockSize(), getNextOutputStream().getBlockSize());
+}
+
+
 // dotFilteredInputStream
 
 dotFilteredInputStream::dotFilteredInputStream(inputStream& is)
diff --git a/src/utility/stream.cpp b/src/utility/stream.cpp
index bb5300ef..8fbf337b 100644
--- a/src/utility/stream.cpp
+++ b/src/utility/stream.cpp
@@ -38,7 +38,7 @@ namespace utility {
 
 // stream
 
-stream::size_type stream::getBlockSize() const
+stream::size_type stream::getBlockSize()
 {
 	return 32768;  // 32 KB
 }
@@ -468,7 +468,7 @@ void outputStreamSocketAdapter::flush()
 }
 
 
-stream::size_type outputStreamSocketAdapter::getBlockSize() const
+stream::size_type outputStreamSocketAdapter::getBlockSize()
 {
 	return 16384;  // 16 KB
 }
@@ -511,7 +511,7 @@ stream::size_type inputStreamSocketAdapter::skip
 }
 
 
-stream::size_type inputStreamSocketAdapter::getBlockSize() const
+stream::size_type inputStreamSocketAdapter::getBlockSize()
 {
 	return 16384;  // 16 KB
 }