Change the sC packet handling to support the multiprocess extension.
Instead of returning the first thread, we return the first thread of the
current process.

Signed-off-by: Luc Michel <luc.michel@greensocs.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
---
 gdbstub.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/gdbstub.c b/gdbstub.c
index ba8b1a3413..9be83486f5 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -1546,13 +1546,18 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
             type = strtoul(p, (char **)&p, 16);
             sstep_flags = type;
             put_packet(s, "OK");
             break;
         } else if (strcmp(p,"C") == 0) {
-            /* "Current thread" remains vague in the spec, so always return
-             *  the first CPU (gdb returns the first thread). */
-            put_packet(s, "QC1");
+            /* "Current thread" remains vague in the spec, so always return the
+             * first thread of the current process (gdb returns the first
+             * thread).
+             */
+            cpu = get_first_cpu_in_process(s, gdb_get_cpu_process(s, s->g_cpu));
+            snprintf(buf, sizeof(buf), "QC%s",
+                     gdb_fmt_thread_id(s, cpu, thread_id, sizeof(thread_id)));
+            put_packet(s, buf);
             break;
         } else if (strcmp(p,"fThreadInfo") == 0) {
             s->query_cpu = first_cpu;
             goto report_cpuinfo;
         } else if (strcmp(p,"sThreadInfo") == 0) {
-- 
2.19.1