Do not generate 7-bit value for parameter if RFC-2231 extended value is generated (thanks to Eugene A. Shatokhin).

1 files changed, 43 insertions, 6 deletions

diff --git a/src/parameter.cpp b/src/parameter.cpp
index 6cd8d1fd..53adacae 100644
--- a/src/parameter.cpp
+++ b/src/parameter.cpp
@@ -257,11 +257,23 @@ void parameter::generate(utility::outputStream& os, const string::size_type maxL
 
 	// For compatibility with implementations that do not understand RFC-2231,
 	// also generate a normal "7bit/us-ascii" parameter
+
+	// [By Eugene A. Shatokhin]
+	// Note that if both the normal "7bit/us-ascii" value and the extended
+	// value are present, the latter can be ignored by mail processing systems.
+	// This may lead to annoying problems, for example, with strange names of
+	// attachments with all but 7-bit ascii characters removed, etc. To avoid
+	// this, I would suggest not to create "7bit/us-ascii" value if the extended
+	// value is to be generated.
+
+	// A stream for a temporary storage
+	std::ostringstream sevenBitBuffer;
+
 	string::size_type pos = curLinePos;
 
 	if (pos + name.length() + 10 + value.length() > maxLineLength)
 	{
-		os << NEW_LINE_SEQUENCE;
+		sevenBitBuffer << NEW_LINE_SEQUENCE;
 		pos = NEW_LINE_SEQUENCE_LENGTH;
 	}
 
@@ -301,12 +313,12 @@ void parameter::generate(utility::outputStream& os, const string::size_type maxL
 
 	if (needQuoting)
 	{
-		os << name << "=\"";
+		sevenBitBuffer << name << "=\"";
 		pos += name.length() + 2;
 	}
 	else
 	{
-		os << name << "=";
+		sevenBitBuffer << name << "=";
 		pos += name.length() + 1;
 	}
 
@@ -318,12 +330,12 @@ void parameter::generate(utility::outputStream& os, const string::size_type maxL
 
 		if (/* needQuoting && */ (c == '"' || c == '\\'))  // 'needQuoting' is implicit
 		{
-			os << '\\' << value[i];  // escape 'x' with '\x'
+			sevenBitBuffer << '\\' << value[i];  // escape 'x' with '\x'
 			pos += 2;
 		}
 		else if (parserHelpers::isAscii(c))
 		{
-			os << value[i];
+			sevenBitBuffer << value[i];
 			++pos;
 		}
 		else
@@ -334,17 +346,31 @@ void parameter::generate(utility::outputStream& os, const string::size_type maxL
 
 	if (needQuoting)
 	{
-		os << '"';
+		sevenBitBuffer << '"';
 		++pos;
 	}
 
+#if VMIME_ALWAYS_GENERATE_7BIT_PARAMETER
+	os << sevenBitBuffer;
+#endif // !VMIME_ALWAYS_GENERATE_7BIT_PARAMETER
+
 	// Also generate an extended parameter if the value contains 8-bit characters
 	// or is too long for a single line
 	if (extended || cutValue)
 	{
+
+#if VMIME_ALWAYS_GENERATE_7BIT_PARAMETER
+
 		os << ';';
 		++pos;
 
+#else // !VMIME_ALWAYS_GENERATE_7BIT_PARAMETER
+
+		// The data output to 'sevenBitBuffer' will be discarded in this case
+		pos = curLinePos;
+
+#endif // VMIME_ALWAYS_GENERATE_7BIT_PARAMETER
+
 		/* RFC-2231
 		 * ========
 		 *
@@ -477,6 +503,17 @@ void parameter::generate(utility::outputStream& os, const string::size_type maxL
 			}
 		}
 	}
+#if !VMIME_ALWAYS_GENERATE_7BIT_PARAMETER
+	else
+	{
+		// The value does not contain 8-bit characters and
+		// is short enough for a single line.
+		// "7bit/us-ascii" will suffice in this case.
+
+		// Output what has been stored in temporary buffer so far
+		os << sevenBitBuffer.str();
+	}
+#endif // !VMIME_ALWAYS_GENERATE_7BIT_PARAMETER
 
 	if (newLinePos)
 		*newLinePos = pos;