From 92e2f4e42074693bdc540ec9d0ae7392c7771a65 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mjumper@apache.org>
Date: Mon, 18 Apr 2016 18:53:12 -0700
Subject: [PATCH 1/4] GUACAMOLE-33: Restore guac_common_cursor_remove_user()
 (reverts commit af7968e).

---
 src/common/guac_cursor.c |  9 +++++++++
 src/common/guac_cursor.h | 15 +++++++++++++++
 src/protocols/vnc/user.c |  9 +++++++++
 src/protocols/vnc/user.h |  5 +++++
 4 files changed, 38 insertions(+)

diff --git a/src/common/guac_cursor.c b/src/common/guac_cursor.c
index e376ab03..4ed66b1d 100644
--- a/src/common/guac_cursor.c
+++ b/src/common/guac_cursor.c
@@ -367,3 +367,12 @@ void guac_common_cursor_set_blank(guac_common_cursor* cursor) {
 
 }
 
+void guac_common_cursor_remove_user(guac_common_cursor* cursor,
+        guac_user* user) {
+
+    /* Disassociate from given user */
+    if (cursor->user == user)
+        cursor->user = NULL;
+
+}
+
diff --git a/src/common/guac_cursor.h b/src/common/guac_cursor.h
index ae359b7f..9db7067d 100644
--- a/src/common/guac_cursor.h
+++ b/src/common/guac_cursor.h
@@ -249,4 +249,19 @@ void guac_common_cursor_set_ibar(guac_common_cursor* cursor);
  */
 void guac_common_cursor_set_blank(guac_common_cursor* cursor);
 
+/**
+ * Removes the given user, such that future synchronization will not occur.
+ * This is necessary when a user leaves the connection. If a user leaves the
+ * connection and this is not called, the corresponding guac_user and socket
+ * may cease to be valid, and future synchronization attempts will segfault.
+ *
+ * @param cursor
+ *     The cursor to remove the user from.
+ *
+ * @param user
+ *     The user to remove.
+ */
+void guac_common_cursor_remove_user(guac_common_cursor* cursor,
+        guac_user* user);
+
 #endif
diff --git a/src/protocols/vnc/user.c b/src/protocols/vnc/user.c
index 0b89d7c9..53423a11 100644
--- a/src/protocols/vnc/user.c
+++ b/src/protocols/vnc/user.c
@@ -97,3 +97,12 @@ int guac_vnc_user_join_handler(guac_user* user, int argc, char** argv) {
 
 }
 
+int guac_vnc_user_leave_handler(guac_user* user) {
+
+    guac_vnc_client* vnc_client = (guac_vnc_client*) user->client->data;
+
+    guac_common_cursor_remove_user(vnc_client->display->cursor, user);
+
+    return 0;
+}
+
diff --git a/src/protocols/vnc/user.h b/src/protocols/vnc/user.h
index 125e4965..e74b2a05 100644
--- a/src/protocols/vnc/user.h
+++ b/src/protocols/vnc/user.h
@@ -29,5 +29,10 @@
  */
 guac_user_join_handler guac_vnc_user_join_handler;
 
+/**
+ * Handler for leaving users.
+ */
+guac_user_leave_handler guac_vnc_user_leave_handler;
+
 #endif
 

From 46b29edc5f64d361a6d190b67425910423a7b3a9 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mjumper@apache.org>
Date: Mon, 18 Apr 2016 18:58:16 -0700
Subject: [PATCH 2/4] GUACAMOLE-33: Actually use VNC's leave handler.

---
 src/protocols/vnc/client.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/protocols/vnc/client.c b/src/protocols/vnc/client.c
index 10391dd3..f3840bb7 100644
--- a/src/protocols/vnc/client.c
+++ b/src/protocols/vnc/client.c
@@ -52,6 +52,7 @@ int guac_client_init(guac_client* client) {
 
     /* Set handlers */
     client->join_handler = guac_vnc_user_join_handler;
+    client->leave_handler = guac_vnc_user_leave_handler;
     client->free_handler = guac_vnc_client_free_handler;
 
     return 0;

From 82fd6a279b110a7d1cab7a7f3c48c9dfcaecb7e3 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mjumper@apache.org>
Date: Mon, 18 Apr 2016 19:03:38 -0700
Subject: [PATCH 3/4] GUACAMOLE-33: Implement leave handlers for RDP, SSH, and
 telnet.

---
 src/protocols/rdp/user.c    |  9 +++++++++
 src/protocols/rdp/user.h    |  5 +++++
 src/protocols/ssh/user.c    |  9 +++++++++
 src/protocols/ssh/user.h    |  9 +++++++--
 src/protocols/telnet/user.c | 10 ++++++++++
 src/protocols/telnet/user.h |  5 +++++
 6 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/src/protocols/rdp/user.c b/src/protocols/rdp/user.c
index 6ded2eb8..af597dbd 100644
--- a/src/protocols/rdp/user.c
+++ b/src/protocols/rdp/user.c
@@ -122,3 +122,12 @@ int guac_rdp_user_file_handler(guac_user* user, guac_stream* stream,
     return 0;
 }
 
+int guac_rdp_user_leave_handler(guac_user* user) {
+
+    guac_rdp_client* rdp_client = (guac_rdp_client*) user->client->data;
+
+    guac_common_cursor_remove_user(rdp_client->display->cursor, user);
+
+    return 0;
+}
+
diff --git a/src/protocols/rdp/user.h b/src/protocols/rdp/user.h
index fe94d3e8..99b8c578 100644
--- a/src/protocols/rdp/user.h
+++ b/src/protocols/rdp/user.h
@@ -27,6 +27,11 @@
  */
 guac_user_join_handler guac_rdp_user_join_handler;
 
+/**
+ * Handler for leaving users.
+ */
+guac_user_leave_handler guac_rdp_user_leave_handler;
+
 /**
  * Handler for received simple file uploads. This handler will automatically
  * select between RDPDR and SFTP depending on which is available and which has
diff --git a/src/protocols/ssh/user.c b/src/protocols/ssh/user.c
index fc9913c9..4a224a0b 100644
--- a/src/protocols/ssh/user.c
+++ b/src/protocols/ssh/user.c
@@ -82,3 +82,12 @@ int guac_ssh_user_join_handler(guac_user* user, int argc, char** argv) {
 
 }
 
+int guac_ssh_user_leave_handler(guac_user* user) {
+
+    guac_ssh_client* ssh_client = (guac_ssh_client*) user->client->data;
+
+    guac_common_cursor_remove_user(ssh_client->term->cursor, user);
+
+    return 0;
+}
+
diff --git a/src/protocols/ssh/user.h b/src/protocols/ssh/user.h
index b9e99400..8287fed4 100644
--- a/src/protocols/ssh/user.h
+++ b/src/protocols/ssh/user.h
@@ -17,8 +17,8 @@
  * under the License.
  */
 
-#ifndef GUAC_VNC_USER_H
-#define GUAC_VNC_USER_H
+#ifndef GUAC_SSH_USER_H
+#define GUAC_SSH_USER_H
 
 #include "config.h"
 
@@ -29,5 +29,10 @@
  */
 guac_user_join_handler guac_ssh_user_join_handler;
 
+/**
+ * Handler for leaving users.
+ */
+guac_user_leave_handler guac_ssh_user_leave_handler;
+
 #endif
 
diff --git a/src/protocols/telnet/user.c b/src/protocols/telnet/user.c
index 45855bde..427112b6 100644
--- a/src/protocols/telnet/user.c
+++ b/src/protocols/telnet/user.c
@@ -78,3 +78,13 @@ int guac_telnet_user_join_handler(guac_user* user, int argc, char** argv) {
 
 }
 
+int guac_telnet_user_leave_handler(guac_user* user) {
+
+    guac_telnet_client* telnet_client =
+        (guac_telnet_client*) user->client->data;
+
+    guac_common_cursor_remove_user(telnet_client->term->cursor, user);
+
+    return 0;
+}
+
diff --git a/src/protocols/telnet/user.h b/src/protocols/telnet/user.h
index 0968f679..910f0cb5 100644
--- a/src/protocols/telnet/user.h
+++ b/src/protocols/telnet/user.h
@@ -29,5 +29,10 @@
  */
 guac_user_join_handler guac_telnet_user_join_handler;
 
+/**
+ * Handler for leaving users.
+ */
+guac_user_leave_handler guac_telnet_user_leave_handler;
+
 #endif
 

From 2b8e1555c68b3eab2b401e506849353d7a04e29e Mon Sep 17 00:00:00 2001
From: Michael Jumper <mjumper@apache.org>
Date: Mon, 18 Apr 2016 20:07:54 -0700
Subject: [PATCH 4/4] GUACAMOLE-33: Fix comment regarding user removal.

---
 src/common/guac_cursor.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/common/guac_cursor.h b/src/common/guac_cursor.h
index 9db7067d..a6d9681e 100644
--- a/src/common/guac_cursor.h
+++ b/src/common/guac_cursor.h
@@ -252,8 +252,8 @@ void guac_common_cursor_set_blank(guac_common_cursor* cursor);
 /**
  * Removes the given user, such that future synchronization will not occur.
  * This is necessary when a user leaves the connection. If a user leaves the
- * connection and this is not called, the corresponding guac_user and socket
- * may cease to be valid, and future synchronization attempts will segfault.
+ * connection and this is not called, the mouse cursor state may not update
+ * correctly in response to mouse events.
  *
  * @param cursor
  *     The cursor to remove the user from.