From aed72ca85e23f61673f10e6217db47571aa28785 Mon Sep 17 00:00:00 2001
From: Marek Marczykowski <marmarek@invisiblethingslab.com>
Date: Mon, 2 Jan 2012 03:59:14 +0100
Subject: [PATCH] vm/file-editor: wait for Xorg (and qubes-session) before
 starting up editor (#400)

---
 appvm/vm-file-editor.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/appvm/vm-file-editor.c b/appvm/vm-file-editor.c
index 86956e89..ab286934 100644
--- a/appvm/vm-file-editor.c
+++ b/appvm/vm-file-editor.c
@@ -49,15 +49,44 @@ void send_file_back(char * filename)
 int
 main()
 {
-	struct stat stat_pre, stat_post;
+	struct stat stat_pre, stat_post, session_stat;
 	char *filename = get_filename();
 	int child, status, log_fd;
+	FILE *waiter_pidfile;
 
 	copy_file(filename);
 	if (stat(filename, &stat_pre)) {
 		perror("stat pre");
 		exit(1);
 	}
+	// wait for X server to starts (especially in DispVM)
+	if (stat("/tmp/qubes-session-env", &session_stat)) {
+		switch (child = fork()) {
+			case -1:
+				perror("fork");
+				exit(1);
+			case 0:
+				waiter_pidfile = fopen("/tmp/qubes-session-waiter", "a");
+				if (waiter_pidfile == NULL) {
+					perror("fopen waiter_pidfile");
+					exit(1);
+				}
+				fprintf(waiter_pidfile, "%d\n", getpid());
+				fclose(waiter_pidfile);
+				// check the second time, to prevent race
+				if (stat("/tmp/qubes-session-env", &session_stat)) {
+					// wait for qubes-session notify
+					pause();
+				}
+				exit(0);
+			default:
+				waitpid(child, &status, 0);
+				if (WIFEXITED(status) && WEXITSTATUS(status) != 0) {
+					//propagate exit code from child
+					exit(WEXITSTATUS(status));
+				}
+		}
+	}
 	switch (child = fork()) {
 		case -1:
 			perror("fork");