diff -urN src/gdb/gdbserver/server.c dev/gdb/gdbserver/server.c
--- src/gdb/gdbserver/server.c	2007-03-29 05:37:17.000000000 +0200
+++ dev/gdb/gdbserver/server.c	2007-04-27 12:31:45.000000000 +0200
@@ -259,6 +259,14 @@
 {
   static struct inferior_list_entry *thread_ptr;
 
+  /* Reply the current thread id.  */
+  if (strcmp ("qC", own_buf) == 0)
+    {
+      sprintf (own_buf, "QC%lx",
+        ((struct inferior_list_entry *) current_inferior)->id);
+      return;
+    }
+
   if (strcmp ("qSymbol::", own_buf) == 0)
     {
       if (the_target->look_up_symbols != NULL)