From 212074c21dc84bba181c8ffde97a6a49b5d25675 Mon Sep 17 00:00:00 2001
From: Dmitry Sapozhnikov <11535558+o-sdn-o@users.noreply.github.com>
Date: Sat, 4 Oct 2025 19:57:18 +0500
Subject: [PATCH 1/2] Fix the SIGWINCH interrupt makes the write operation
 think its failed, and causes it to try again.

xlink https://github.com/directvt/vtm/issues/819#issuecomment-3368223680

> When a window resize event is received (terminal generates WINDOW_BUFFER_SIZE_EVENT event when switching between alternate/normal buffer mode), the errno becomes EINTR which causes the write operation think its failed.

potentially fixes PowerShell/Win32-OpenSSH#2275
---
 contrib/win32/win32compat/console.c | 11 -----------
 contrib/win32/win32compat/signal.c  |  2 +-
 2 files changed, 1 insertion(+), 12 deletions(-)

diff --git a/contrib/win32/win32compat/console.c b/contrib/win32/win32compat/console.c
index f34a8d19d40..12673ad3198 100644
--- a/contrib/win32/win32compat/console.c
+++ b/contrib/win32/win32compat/console.c
@@ -225,17 +225,6 @@ ConEnterRawMode()
 	ScrollBottom = ConVisibleWindowHeight();
 	
 	in_raw_mode = 1;
-
-	/*
-	Consume and ignore the first WINDOW_BUFFER_SIZE_EVENT, as we've triggered it ourselves by updating the console settings above.
-	Not consuming this event can cause a race condition: the event can cause a write to the console to be printed twice as the
-	SIGWINCH interrupt makes the write operation think its failed, and causes it to try again.
-	*/
-	INPUT_RECORD peek_input;
-	int out_count = 0;
-	if (PeekConsoleInputW(GetConsoleInputHandle(), &peek_input, 1, &out_count) && peek_input.EventType == WINDOW_BUFFER_SIZE_EVENT) {
-		ReadConsoleInputW(GetConsoleInputHandle(), &peek_input, 1, &out_count);
-	}
 }
 
 /* Used to Uninitialize the Console */
diff --git a/contrib/win32/win32compat/signal.c b/contrib/win32/win32compat/signal.c
index f61cdd882d8..e6eeda5cd53 100644
--- a/contrib/win32/win32compat/signal.c
+++ b/contrib/win32/win32compat/signal.c
@@ -230,7 +230,7 @@ sw_process_pending_signals()
 				w32_raise(exp[i]);
 				/* dont error EINTR for SIG_ALRM, */
 				/* sftp client is not expecting it */
-				if (exp[i] != W32_SIGALRM)
+				if (exp[i] != W32_SIGALRM && exp[i] != W32_SIGWINCH)
 					sig_int = TRUE;
 			} else if (exp[i] == W32_SIGCHLD) /*if SIGCHLD is SIG_IGN, reap zombies*/
 				sw_cleanup_child_zombies();

From 811aa23b618616ada5c558b63730b12eb4b4dde4 Mon Sep 17 00:00:00 2001
From: Dmitry Sapozhnikov <11535558+o-sdn-o@users.noreply.github.com>
Date: Sun, 5 Oct 2025 13:29:01 +0500
Subject: [PATCH 2/2] #2275: Add comments to the fix the SIGWINCH interrupt
 makes the write operation think its failed

---
 contrib/win32/win32compat/signal.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/contrib/win32/win32compat/signal.c b/contrib/win32/win32compat/signal.c
index e6eeda5cd53..24560eceed9 100644
--- a/contrib/win32/win32compat/signal.c
+++ b/contrib/win32/win32compat/signal.c
@@ -228,8 +228,8 @@ sw_process_pending_signals()
 		if (sigismember(&pending_tmp, exp[i])) {
 			if (sig_handlers[exp[i]] != W32_SIG_IGN) {
 				w32_raise(exp[i]);
-				/* dont error EINTR for SIG_ALRM, */
-				/* sftp client is not expecting it */
+				/* don't set errno=EINTR on SIGALRM, sftp client is not expecting it */
+				/* don't set errno=EINTR on SIGWINCH in order to avoid breaking the sequence of waiting for completion of IO operations. */
 				if (exp[i] != W32_SIGALRM && exp[i] != W32_SIGWINCH)
 					sig_int = TRUE;
 			} else if (exp[i] == W32_SIGCHLD) /*if SIGCHLD is SIG_IGN, reap zombies*/