diff -r 1d3500806565 -r 16590c9c497c test/buffer_tests.c
--- a/test/buffer_tests.c	Wed Oct 10 13:58:51 2012 +0200
+++ b/test/buffer_tests.c	Wed Oct 10 14:18:06 2012 +0200
@@ -145,6 +145,30 @@
     free(buffer);
 }
 
+UCX_TEST_IMPLEMENT(test_ucx_buffer_write_ax) {
+    char *buffer = malloc(4);
+
+    UcxBuffer *b = ucx_buffer_new(buffer, 16,
+            UCX_BUFFER_AUTOEXTEND | UCX_BUFFER_AUTOFREE);
+    int r;
+
+    UCX_TEST_BEGIN
+
+    char* teststring = "this is way too much";
+    r = ucx_buffer_write(teststring, 1, 20, b);
+    buffer = b->space; /* autoextend is enabled, so we MUST retrieve pointer */
+    UCX_TEST_ASSERT(r == 20, "not all characters written");
+    UCX_TEST_ASSERT(b->size == 32, "buffer not properly extended");
+    UCX_TEST_ASSERT(b->pos == 20, "position incorrect");
+    UCX_TEST_ASSERT(memcmp(buffer,
+            "this is way too much\0\0\0\0\0\0\0\0\0\0\0\0", 32) == 0,
+            "incorrect buffer content");
+
+    UCX_TEST_END
+
+    ucx_buffer_free(b);
+}
+
 UCX_TEST_IMPLEMENT(test_ucx_buffer_read) {
     char *buffer = malloc(16);
     memset(buffer, 56, 8);