[PATCH 08/12] gdbserver: Fix vAttach response when attaching is not supported

[Pedro Alves]

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
---
 gdbserver/server.cc | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index 2633df08ddb..789af36d9a4 100644
--- 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)
     {
-- 
2.43.2