From ebceb8bc9494af6d93ace9f6ea84bb3d09adb8f3 Mon Sep 17 00:00:00 2001
From: Jacob Nevins <jacobn@chiark.greenend.org.uk>
Date: Wed, 2 Nov 2022 23:51:57 +0000
Subject: [PATCH] Windows: fix terminal hang with resize forbidden.

A server attempt to resize the window (for instance via DECCOLM) when
"When window is resized" was set to "Forbid resizing completely" would
cause all terminal output to be suspended, due to the resize attempt
never being acknowledged.

(There are other code paths like this, which I've fixed for
completeness, but I don't think they have any effect: the terminal
filters out resize attempts to the current size before this point, and
even if a server can get such a request through the SUPDUP protocol, the
test for that is wrong and will never fire -- this needs fixing
separately.)
---
 windows/window.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/windows/window.c b/windows/window.c
index 82bbe8e6..0cc10e40 100644
--- a/windows/window.c
+++ b/windows/window.c
@@ -1656,20 +1656,27 @@ static void wintw_request_resize(TermWin *tw, int w, int h)
     WinGuiSeat *wgs = container_of(tw, WinGuiSeat, termwin);
     const struct BackendVtable *vt;
     int width, height;
+    int resize_action = conf_get_int(wgs->conf, CONF_resize_action);
+    bool deny_resize = false;
 
-    /* If the window is maximized suppress resizing attempts */
-    if (IsZoomed(wgs->term_hwnd)) {
-        if (conf_get_int(wgs->conf, CONF_resize_action) == RESIZE_TERM) {
-            term_resize_request_completed(wgs->term);
-            return;
-        }
+    /* Suppress server-originated resizing attempts if local resizing
+     * is disabled entirely, or if it's supposed to change
+     * rows/columns but the window is maximised. */
+    if (resize_action == RESIZE_DISABLED
+        || (resize_action == RESIZE_TERM && IsZoomed(wgs->term_hwnd))) {
+        deny_resize = true;
     }
 
-    if (conf_get_int(wgs->conf, CONF_resize_action) == RESIZE_DISABLED) return;
     vt = backend_vt_from_proto(be_default_protocol);
     if (vt && vt->flags & BACKEND_RESIZE_FORBIDDEN)
+        deny_resize = true;
+    if (h == wgs->term->rows && w == wgs->term->cols) deny_resize = true;
+
+    /* We still need to acknowledge a suppressed resize attempt. */
+    if (deny_resize) {
+        term_resize_request_completed(wgs->term);
         return;
-    if (h == wgs->term->rows && w == wgs->term->cols) return;
+    }
 
     /* Sanity checks ... */
     {
@@ -1690,8 +1697,7 @@ static void wintw_request_resize(TermWin *tw, int w, int h)
         }
     }
 
-    if (conf_get_int(wgs->conf, CONF_resize_action) != RESIZE_FONT &&
-        !IsZoomed(wgs->term_hwnd)) {
+    if (resize_action != RESIZE_FONT && !IsZoomed(wgs->term_hwnd)) {
         width = extra_width + font_width * w;
         height = extra_height + font_height * h;