Added helper function to replace header field.

src/header.cpp

@@ -276,6 +276,13 @@ void header::removeField(const size_t pos)
 }
 
 
+void header::replaceField(ref <headerField> field, ref <headerField> newField)
+{
+	insertFieldBefore(field, newField);
+	removeField(field);
+}
+
+
 void header::removeAllFields()
 {
 	m_fields.clear();

tests/parser/headerTest.cpp

@@ -43,6 +43,8 @@ VMIME_TEST_SUITE_BEGIN
 		VMIME_TEST(testInsertFieldAfter1)
 		VMIME_TEST(testInsertFieldAfter2)
 
+		VMIME_TEST(testReplaceField)
+
 		VMIME_TEST(testRemoveField1)
 		VMIME_TEST(testRemoveField2)
 
@@ -192,6 +194,23 @@ VMIME_TEST_SUITE_BEGIN
 		VASSERT_EQ("Third value", "C: c", headerTest::getFieldValue(*res[2]));
 	}
 
+	// replaceField
+	void testReplaceField()
+	{
+		vmime::header hdr;
+		hdr.parse("A: a\r\nB: b\r\nC: c\r\n");
+
+		vmime::ref <vmime::headerField> hf = vmime::headerFieldFactory::getInstance()->create("Z", "z");
+		hdr.replaceField(hdr.getField("B"), hf);
+
+		std::vector <vmime::ref <vmime::headerField> > res = hdr.getFieldList();
+
+		VASSERT_EQ("Count", static_cast <unsigned int>(3), res.size());
+		VASSERT_EQ("First value", "A: a", headerTest::getFieldValue(*res[0]));
+		VASSERT_EQ("Second value", "Z: z", headerTest::getFieldValue(*res[1]));
+		VASSERT_EQ("Third value", "C: c", headerTest::getFieldValue(*res[2]));
+	}
+
 	// removeField
 	void testRemoveField1()
 	{

vmime/header.hpp

@@ -170,6 +170,14 @@ public:
 	  */
 	void removeField(const size_t pos);
 
+	/** Replaces a field with another field.
+	  *
+	  * @param field field to be replaced
+	  * @param newField field to replace with
+	  * @throw exceptions::no_such_field if the field is not in the list
+	  */
+	void replaceField(ref <headerField> field, ref <headerField> newField);
+
 	/** Remove all fields from the list.
 	  */
 	void removeAllFields();