gh-551: Screen scrambled when pressing Alt-F9 under Windows 11 22H2

far/changelog

@@ -1,3 +1,8 @@
+--------------------------------------------------------------------------------
+drkns 07.10.2022 23:13:59 +0100 - build 6038
+
+1. gh-551: Screen scrambled when pressing Alt-F9 under Windows 11 22H2
+
 --------------------------------------------------------------------------------
 drkns 06.10.2022 17:43:00 +0100 - build 6037
 

far/interf.cpp

@@ -540,16 +540,50 @@ void SetVideoMode()
 	}
 }
 
+static bool validate_console_size(point const Size)
+{
+	// https://github.com/microsoft/terminal/issues/10337
+
+	// As of 7 Oct 2022 GetLargestConsoleWindowSize is broken in WT.
+	// It takes the current screen resolution and divides it by an inadequate font size, e.g. 1x16.
+
+	// It is unlikely that it is ever gonna be fixed, so we do a few very basic checks here to filter out obvious rubbish.
+
+	if (Size.x <= 0 || Size.y <= 0)
+		return false;
+
+	// A typical screen ratio these days is roughly 2:1.
+	// A typical font cell is about 1:2, so the expected screen ratio in cells
+	// is around 4 for the landscape and around 1 for the portrait, give or take.
+	// Anything twice larger than that is likely rubbish.
+	if (Size.x >= 8 * Size.y || Size.y >= 2 * Size.x)
+		return false;
+
+	// The API works with SHORTs, anything larger than that makes no sense.
+	if (Size.x >= std::numeric_limits<SHORT>::max() || Size.y >= std::numeric_limits<SHORT>::max())
+		return false;
+
+	return true;
+}
+
 void ChangeVideoMode(bool Maximize)
 {
 	point coordScreen;
 
 	if (Maximize)
 	{
-		SendMessage(console.GetWindow(),WM_SYSCOMMAND,SC_MAXIMIZE,0);
 		coordScreen = console.GetLargestWindowSize();
+
+		if (!validate_console_size(coordScreen))
+		{
+			LOGERROR(L"GetLargestConsoleWindowSize(): the reported size ({{{}, {}}} makes no sense. Talk to your terminal or OS vendor."sv, coordScreen.x, coordScreen.y);
+			return;
+		}
+
 		coordScreen.x += Global->Opt->ScrSize.DeltaX;
 		coordScreen.y += Global->Opt->ScrSize.DeltaY;
+
+		SendMessage(console.GetWindow(), WM_SYSCOMMAND, SC_MAXIMIZE, 0);
 	}
 	else
 	{

far/vbuild.m4

@@ -1 +1 @@
-6037
+6038