commit ea080950069d12713bf146472e18750210c4a24f
from: Omar Polo <op@omarpolo.com>
date: Tue Jul 20 08:34:58 2021 UTC

touch ~/.telescope/crashed if the connection to ui process dies

commit - 8064b84908439d34f2d8c11f09107d7e226d3809
commit + ea080950069d12713bf146472e18750210c4a24f
blob - 8a803f10ae2871a1068d20eb8d286357f2740cac
blob + c49aada1867eade200f189c326cbc652fdde5370
--- fs.c
+++ fs.c
@@ -55,6 +55,7 @@ static FILE			*session;
 static char	lockfile_path[PATH_MAX];
 static char	bookmark_file[PATH_MAX];
 static char	known_hosts_file[PATH_MAX], known_hosts_tmp[PATH_MAX];
+static char	crashed_file[PATH_MAX];
 
 char	session_file[PATH_MAX];
 
@@ -350,7 +351,23 @@ static void
 handle_dispatch_imsg(int fd, short ev, void *d)
 {
 	struct imsgev	*iev = d;
-	dispatch_imsg(iev, ev, handlers, sizeof(handlers));
+	int		 e;
+
+	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1) {
+		/*
+		 * This should leave a ~/.telescope/crashed file to
+		 * trigger about:crash on next run.  Unfortunately, if
+		 * the main process dies the fs sticks around and
+		 * doesn't notice that the fd was closed.  Why EV_READ
+		 * is not triggered when a fd is closed on the other end?
+		 */
+		e = errno;
+		if ((fd = open(crashed_file, O_CREAT|O_TRUNC|O_WRONLY, 0600))
+		    == -1)
+			err(1, "open");
+		close(fd);
+		errx(1, "connection closed: %s", strerror(e));
+	}
 }
 
 static int
@@ -386,6 +403,9 @@ fs_init(void)
 	strlcpy(session_file, getenv("HOME"), sizeof(session_file));
 	strlcat(session_file, "/.telescope/session", sizeof(session_file));
 
+	strlcpy(crashed_file, getenv("HOME"), sizeof(crashed_file));
+	strlcat(crashed_file, "/.telescope/crashed", sizeof(crashed_file));
+
 	return 1;
 }
 
blob - e42024b1ac845d80b1ff160f43770ad712f73b9a
blob + 165dfe5ff526750c3ca47b1ab1d4f6b2ca5d1034
--- gemini.c
+++ gemini.c
@@ -567,7 +567,9 @@ static void
 handle_dispatch_imsg(int fd, short ev, void *d)
 {
 	struct imsgev	*iev = d;
-	dispatch_imsg(iev, ev, handlers, sizeof(handlers));
+
+	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1)
+		err(1, "connection closed");
 }
 
 static int
blob - 06045f111b22cb336a414b93ebc84d74c367ccd0
blob + e01b03d74d63d9fee1f99ba2c2cfec45d0ec49fc
--- telescope.c
+++ telescope.c
@@ -541,7 +541,9 @@ static void
 handle_dispatch_imsg(int fd, short ev, void *d)
 {
 	struct imsgev	*iev = d;
-	dispatch_imsg(iev, ev, handlers, sizeof(handlers));
+
+	if (dispatch_imsg(iev, ev, handlers, sizeof(handlers)) == -1)
+		err(1, "connection closed");
 }
 
 static void
blob - 0da6cb218cdd79482477250ca15f821435846658
blob + 3824cee6e40bdc431ec84e473727dc570b4738bb
--- telescope.h
+++ telescope.h
@@ -337,7 +337,7 @@ int		 mark_nonblock(int);
 int		 has_prefix(const char*, const char*);
 int		 unicode_isspace(uint32_t);
 int		 unicode_isgraph(uint32_t);
-void		 dispatch_imsg(struct imsgev*, short, imsg_handlerfn**, size_t);
+int		 dispatch_imsg(struct imsgev *, short, imsg_handlerfn **, size_t);
 int		 imsg_compose_event(struct imsgev *, uint16_t, uint32_t, pid_t, int, const void *, uint16_t);
 
 /* wrap.c */
blob - 9d51f36474be436c2bd10eae4ecd1f741a37ebd8
blob + 6db63f66abf8ca343e535fd83df530d61fa67243
--- util.c
+++ util.c
@@ -75,7 +75,7 @@ imsg_event_add(struct imsgev *iev)
 	event_add(&iev->ev, NULL);
 }
 
-void
+int
 dispatch_imsg(struct imsgev *iev, short event, imsg_handlerfn **handlers,
     size_t size)
 {
@@ -90,13 +90,13 @@ dispatch_imsg(struct imsgev *iev, short event, imsg_ha
 		if ((n = imsg_read(ibuf)) == -1 && errno != EAGAIN)
 			err(1, "imsg_read error");
 		if (n == 0)
-			err(1, "connection closed");
+			return -1;
 	}
 	if (event & EV_WRITE) {
 		if ((n = msgbuf_write(&ibuf->w)) == -1 && errno != EAGAIN)
 			err(1, "msgbuf_write");
 		if (n == 0)
-			err(1, "connection closed");
+			return -1;
 	}
 
 	for (;;) {
@@ -113,6 +113,7 @@ dispatch_imsg(struct imsgev *iev, short event, imsg_ha
 	}
 
 	imsg_event_add(iev);
+	return 0;
 }
 
 int