patch 8.2.3764: cannot see any text when window was made zero lines

Problem:    Cannot see any text when window was made zero lines or zero
            columns.
Solution:   Ensure there is at least one line and column. (fixes #9307)
diff --git a/src/normal.c b/src/normal.c
index 0fbfe92..d3c4c78 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -608,6 +608,11 @@
 	old_mapped_len = 0;	// do go to Insert mode
     }
 
+    // If the window was made so small that nothing shows, make it at least one
+    // line and one column when typing a command.
+    if (KeyTyped && !KeyStuffed)
+	win_ensure_size();
+
 #ifdef FEAT_CMDL_INFO
     need_flushbuf = add_to_showcmd(c);
 #endif