Don't try to resize terminated sessions and don't allow sessions smaller than...

Don't try to resize terminated sessions and don't allow sessions smaller than 1x1. Fixes crash when closing a window in IR while another window exists and is key.

PseudoTerminal.m

@@ -3503,6 +3503,9 @@ NSString *sessionsKey = @"sessions";
 // Set the session to a size that fits on the screen.
 - (void)safelySetSessionSize:(PTYSession*)aSession rows:(int)rows columns:(int)columns
 {
+    if ([aSession exited]) {
+        return;
+    }
     PtyLog(@"safelySetSessionSize");
     BOOL hasScrollbar = !_fullScreen && ![[PreferencePanel sharedInstance] hideScrollbar];
     if (windowType_ == WINDOW_TYPE_NORMAL) {

VT100Screen.m

@@ -838,6 +838,8 @@ static char* FormatCont(int c)
     if (WIDTH == 0 || HEIGHT == 0 || (new_width==WIDTH && new_height==HEIGHT)) {
         return;
     }
+    new_width = MAX(new_width, 1);
+    new_height = MAX(new_height, 1);
     // create a new buffer and fill it with the default line.
     new_buffer_lines = (screen_char_t*)calloc(new_height * (new_width+1),