fix(control): ignore SIGPIPE so a vanishing client can't kill the emulator

A client that connects and closes before reading (e.g. the HUD's liveness
probe) made the greeting write() raise SIGPIPE, terminating the whole emulator
- this was behind much of the 'it keeps dying' this session. Also: gbhud now
re-resolves the live instance from the registry on every reconnect (skipping
stale sockets by test-connecting), so the HUD follows respawns, and its box
rendering is ANSI-width-correct.

1 files changed, 5 insertions, 0 deletions

diff --git a/src/control.c b/src/control.c
index 322646b..5cea4e0 100644
--- a/src/control.c
+++ b/src/control.c
@@ -11,6 +11,7 @@
 #include <errno.h>
 #include <unistd.h>
 #include <fcntl.h>
+#include <signal.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 
@@ -508,6 +509,10 @@ static void service_client(GB *gb, int i) {
 // ---------------------------------------------------------------------------
 
 void control_open(const char *path) {
+    // A client can connect and vanish before we finish writing (e.g. a liveness
+    // probe that connects and closes without reading the greeting). Ignore
+    // SIGPIPE so those writes fail with EPIPE instead of killing the emulator.
+    signal(SIGPIPE, SIG_IGN);
     for (int i = 0; i < MAX_CLIENTS; i++) clients[i].fd = -1;
 
     listen_fd = socket(AF_UNIX, SOCK_STREAM, 0);