gdbserver: Fix vAttach response when attaching is not supported

handle_v_attach calls attach_inferior, which says:

  "return -1 if attaching is unsupported, 0 if it succeeded, and call
  error() otherwise."

So if attach_inferior return != 0, we have the unsupported case,
meaning we should return the empty packet instead of an error.

In practice, this shouldn't trigger, as vAttach support is supposed to
be reported via qSupported.  But it doesn't hurt to be pedantic here.

Change-Id: I99cce6fa678f2370571e6bca0657451300956127
Approved-By: Tom Tromey <tom@tromey.com>

diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index 2633df08ddb7f195ed815c629c6524c2392ae73c..789af36d9a42cbd496abba574cdaced7338da159 100644 (file)
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -3318,7 +3318,10 @@ handle_v_attach (char *own_buf)
            prepare_resume_reply (own_buf, cs.last_ptid, cs.last_status);
        }
       else
-       write_enn (own_buf);
+       {
+         /* Not supported.  */
+         own_buf[0] = 0;
+       }
     }
   catch (const gdb_exception_error &exception)
     {