* lib/gdb.exp (gdb_skip_xml_test): Add comment.

gdb/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2010-01-07  Doug Evans  <dje@google.com>
+
+	* lib/gdb.exp (gdb_skip_xml_test): Add comment.
+
 2010-01-07  Tom Tromey  <tromey@redhat.com>
 
 	* gdb.base/source.exp: Use correct line number.

gdb/testsuite/lib/gdb.exp

@@ -2730,6 +2730,7 @@ proc gdb_skip_bogus_test { msg } {
 
 # Return true if a test should be skipped due to lack of XML support
 # in the host GDB.
+# NOTE: This must be called while gdb is *not* running.
 
 proc gdb_skip_xml_test { } {
     global gdb_prompt