Deal with more windows console braindeadedness.

The window and the screen buffer are two different things... the
screen buffer must always be the same size as or larger than the
window.  Further, there are times where it's not possible to resize
the windown programatically (new terminal for example).

There still appears to be a stupid bug in what I assume is the
Windows Terminal LCF flag implementation which causes writes to
the beginning of a line that occur after a write to the end of the
previous line to be in the wrong position.  If it's not the LCF flag
(which isn't turned on), it's in their wrapping thing which is extra
irritating since I explocitly turn that off.

src/conio/win32cio.c

@@ -642,6 +642,21 @@ int win32_showmouse(void)
 	return(0);
 }
 
+static bool
+getWindowSize(HANDLE h, int *x, int *y)
+{
+	CONSOLE_SCREEN_BUFFER_INFO inf;
+	SMALL_RECT *r = &inf.srWindow;
+
+	if (!GetConsoleScreenBufferInfo(h, &inf))
+		return false;
+	if (x)
+		*x = r->Right - r->Left + 1;
+	if (y)
+		*y = r->Bottom - r->Top + 1;
+	return true;
+}
+
 void win32_textmode(int mode)
 {
 	HANDLE	h;
@@ -651,6 +666,7 @@ void win32_textmode(int mode)
 	int i;
 	DWORD oldmode;
 	DWORD cmode;
+	int wx, wy;
 
 	modeidx = find_vmode(mode);
 	if (modeidx == -1)
@@ -671,15 +687,26 @@ void win32_textmode(int mode)
 		}
 	}
 
+	if ((h=GetStdHandle(STD_OUTPUT_HANDLE)) == INVALID_HANDLE_VALUE)
+		return;
+
+	/*
+	 * First, we need to set the screen buffer "big enough" for the
+	 * new window, but at least as big as the current window
+	 */
 	sz.X = cio_textinfo.screenwidth > vparams[modeidx].cols ? cio_textinfo.screenwidth : vparams[modeidx].cols;
 	sz.Y = cio_textinfo.screenheight > vparams[modeidx].rows ? cio_textinfo.screenheight : vparams[modeidx].rows;
+	if (getWindowSize(h, &wx, &wy)) {
+		if (wx > sz.X)
+			sz.X = wx;
+		if (wy > sz.Y)
+			sz.Y = wy;
+	}
 	rc.Left=0;
 	rc.Right=vparams[modeidx].cols-1;
 	rc.Top=0;
 	rc.Bottom=vparams[modeidx].rows-1;
 
-	if ((h=GetStdHandle(STD_OUTPUT_HANDLE)) == INVALID_HANDLE_VALUE)
-		return;
 	if (!SetConsoleScreenBufferSize(h,sz)) {
 		DWORD err = GetLastError();
 		switch(err) {
@@ -690,10 +717,21 @@ void win32_textmode(int mode)
 				return;
 		}
 	}
-	if (!SetConsoleWindowInfo(h,TRUE,&rc))
-		return;
+
+	// Now we try to set the window size
+	SetConsoleWindowInfo(h,TRUE,&rc);
+
+	// And finally, we set the screen buffer to *just* fit the window
 	sz.X=vparams[modeidx].cols;
 	sz.Y=vparams[modeidx].rows;
+
+	// Of course, the window may not be the size we asked for...
+	if (getWindowSize(h, &wx, &wy)) {
+		if (wx > sz.X)
+			sz.X = wx;
+		if (wy > sz.Y)
+			sz.Y = wy;
+	}
 	if (!SetConsoleScreenBufferSize(h,sz)) {
 		DWORD err = GetLastError();
 		switch(err) {