[plasma/plasma-login-manager] src: Revert "VirtualTerminal: take over stale VT_PROCESS handler and ignore VT switch..."

Git commit 20935f7ca78f004660b2d7a46e2137f3cec9c772 by David Edmundson.
Committed on 29/07/2026 at 23:12.
Pushed by davidedmundson into branch 'master'.

Revert "VirtualTerminal: take over stale VT_PROCESS handler and ignore VT switch..."

This reverts commit a05fadfb95e229c69e96122bbc9be98ab849d69f

M  +0    -19   src/common/VirtualTerminal.cpp
M  +0    -1    src/common/VirtualTerminal.h
M  +0    -3    src/helper/UserSession.cpp

https://invent.kde.org/plasma/plasma-login-manager/-/commit/20935f7ca78f004660b2d7a46e2137f3cec9c772

diff --git a/src/common/VirtualTerminal.cpp b/src/common/VirtualTerminal.cpp
index 6c1e7737..9e25d5cb 100644
--- a/src/common/VirtualTerminal.cpp
+++ b/src/common/VirtualTerminal.cpp
@@ -109,17 +109,6 @@ static bool handleVtSwitches(int fd)
     return ok;
 }
 
-void ignoreVtSwitches()
-{
-    // For callers that execve() while still the VT_PROCESS owner:
-    // handled dispositions reset to SIG_DFL across exec, so a switch
-    // request in the window before the new compositor takes VT control
-    // would kill the process. SIG_IGN survives exec; the kernel defers
-    // the switch until the compositor re-establishes VT handling.
-    signal(RELEASE_DISPLAY_SIGNAL, SIG_IGN);
-    signal(ACQUIRE_DISPLAY_SIGNAL, SIG_IGN);
-}
-
 static void fixVtMode(int fd, bool vt_auto)
 {
     vt_mode getmodeReply{};
@@ -132,14 +121,6 @@ static void fixVtMode(int fd, bool vt_auto)
         ok = false;
     }
 
-    // The previous VT_PROCESS owner (logind for Wayland greeters)
-    // can clear its VT mode mid-switch, leaving VT_WAITACTIVE hung.
-    // Take over so the relsig handshake completes locally.
-    if (getmodeReply.mode == VT_PROCESS) {
-        ok = handleVtSwitches(fd);
-        modeFixed = true;
-    }
-
     if (getmodeReply.mode != VT_AUTO) {
         goto out;
     }
diff --git a/src/common/VirtualTerminal.h b/src/common/VirtualTerminal.h
index 09eb11b1..456884e7 100644
--- a/src/common/VirtualTerminal.h
+++ b/src/common/VirtualTerminal.h
@@ -47,7 +47,6 @@ int currentVt();
 Terminal openVt(int vt);
 Terminal setUpNewVt();
 void jumpToVt(int vt, bool vt_auto);
-void ignoreVtSwitches();
 }
 }
 
diff --git a/src/helper/UserSession.cpp b/src/helper/UserSession.cpp
index 6f6c22f4..9d9609b7 100644
--- a/src/helper/UserSession.cpp
+++ b/src/helper/UserSession.cpp
@@ -146,9 +146,6 @@ void UserSession::childModifier()
 
     if (vtNumber > 0) {
         VirtualTerminal::jumpToVt(vtNumber, x11Session);
-        // This process becomes the session via execve(); leave the VT
-        // switch signals ignored so they survive the exec.
-        VirtualTerminal::ignoreVtSwitches();
     }
 
 #ifdef Q_OS_LINUX