From: Lennart Poettering <lennart@poettering.net>
Date: Fri, 19 Sep 2025 12:50:53 +0000 (+0200)
Subject: ptyfwd: reset tty when exiting
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=3d97db8f3c3e86b70d09444965ebfddd051df39c;p=thirdparty%2Fsystemd.git

ptyfwd: reset tty when exiting

Let's do a "soft" reset of the TTY when a ptyfwd session ends. This is a
good idea, in order to reset changes to the scrolling window that code
inside the session might have made. A "soft" reset will undo this.

While we are at it, make sure to output the ansi sequences for this
*after* terminating any half-written line, as that is still somewhat
contents of the session, even if it's augmented.
---

diff --git a/src/basic/terminal-util.c b/src/basic/terminal-util.c
index 2106d0db8c7..2175523e201 100644
--- a/src/basic/terminal-util.c
+++ b/src/basic/terminal-util.c
@@ -955,7 +955,7 @@ finish:
         return r;
 }
 
-static int terminal_reset_ansi_seq(int fd) {
+int terminal_reset_ansi_seq(int fd) {
         int r, k;
 
         assert(fd >= 0);
diff --git a/src/basic/terminal-util.h b/src/basic/terminal-util.h
index 28694693533..6428d9a1472 100644
--- a/src/basic/terminal-util.h
+++ b/src/basic/terminal-util.h
@@ -34,6 +34,8 @@
 
 bool isatty_safe(int fd);
 
+int terminal_reset_ansi_seq(int fd);
+
 typedef enum TerminalResetFlags {
         TERMINAL_RESET_SWITCH_TO_TEXT = 1 << 0,
         TERMINAL_RESET_AVOID_ANSI_SEQ = 1 << 1,
diff --git a/src/shared/ptyfwd.c b/src/shared/ptyfwd.c
index 46151ee21b9..6d2b07d2b4d 100644
--- a/src/shared/ptyfwd.c
+++ b/src/shared/ptyfwd.c
@@ -133,13 +133,6 @@ static void pty_forward_disconnect(PTYForward *f) {
                 /* STDIN/STDOUT should not be non-blocking normally, so let's reset it */
                 (void) fd_nonblock(f->output_fd, false);
 
-                if (colors_enabled()) {
-                        (void) loop_write(f->output_fd, ANSI_NORMAL ANSI_ERASE_TO_END_OF_SCREEN, SIZE_MAX);
-
-                        if (f->title)
-                                (void) loop_write(f->output_fd, ANSI_WINDOW_TITLE_POP, SIZE_MAX);
-                }
-
                 if (f->last_char_set && f->last_char != '\n') {
                         const char *s;
 
@@ -153,6 +146,13 @@ static void pty_forward_disconnect(PTYForward *f) {
                         f->last_char = '\n';
                 }
 
+                if (colors_enabled()) {
+                        if (f->title)
+                                (void) loop_write(f->output_fd, ANSI_WINDOW_TITLE_POP, SIZE_MAX);
+
+                        terminal_reset_ansi_seq(f->output_fd);
+                }
+
                 if (f->close_output_fd)
                         f->output_fd = safe_close(f->output_fd);
         }