'del_test' (test of deleting windows and sub-windows) crashes on many…

… systems; you need getch( ) delays so you can see the exact point of failure. Also, the description of what's happening was not very good.

tests/del_test.c

@@ -28,41 +28,56 @@ to crash the second time 'win' is deleted.
    We were not clear as to what is 'supposed' to be done here
 according to the X/Open and SVr4 standards.  But in actual practice,
 it's clearly dangerous to do either of the things described in the
-two questions above.
-
-   PDCursesMod will assert() if you delete a window with a parent.
-(It maintains a list of active windows,  and will also assert() if
-you attempt to 're-delete' a window,  or more generally,  pass in
-a pointer to delwin() that isn't actually a current window.)   */
+two questions above.  Portable curses code should delete windows
+only once,  and should never delete a window with a subwindow.
+PDCursesMod will assert() if you attempt to do either of these.
+More generally,  it maintains a list of "current" windows and will
+assert() if you pass a pointer to delwin() that isn't actually a
+valid window.   */
 
 int main( void)
 {
     WINDOW *win, *sub;
     SCREEN *screen = newterm( NULL, NULL, NULL);
     char buff[90];
+    int line = 1;
 
     noecho();
+    mvaddstr( line++, 1, "Code to test deleting windows.  References :");
+    mvaddstr( line++, 1, "https://www.invisible-island.net/ncurses/man/curs_window.3x.html");
+    mvprintw( line++, 1, "https://lists.gnu.org/archive/html/bug-ncurses/2022-08/msg00006.html");
+    mvprintw( line++, 1, "Source code for this program (del_test.c)");
+    line++;
     win = newwin( 0, 0, 0, 0);
-    move( 1, 1);
-    snprintf( buff, sizeof( buff), "New window %p    %s", (void *)win, longname( ));
-    addstr( buff);
-    move( 2, 1);
+    snprintf( buff, sizeof( buff), "Allocated new window %p    %s", (void *)win, longname( ));
+    mvaddstr( line++, 1, buff);
     sub = subwin( win, 10, 10, 10, 10);
     snprintf( buff, sizeof( buff), "Sub window %p    %s", (void *)sub, curses_version( ));
-    mvaddstr( 2, 1, buff);
-    snprintf( buff, sizeof( buff), "Deleted win : %d (should fail,  it still has a subwindow)", delwin( win));
-    mvaddstr( 4, 1, buff);
+    mvaddstr( line++, 1, buff);
+    mvaddstr( line++, 1, "Next step will attempt to delete the window.  Should fail,  since");
+    mvaddstr( line++, 1, "it has a subwindow.  Hit any key :");
+    getch( );
+    snprintf( buff, sizeof( buff), "Window deleted with return value %d", delwin( win));
+    mvaddstr( line++, 1, buff);
+    line++;
+    mvaddstr( line++, 1, "Will now attempt to delete the sub-window.");
+    mvaddstr( line++, 1, "That ought to succeed.  Hit any key :");
+    getch( );
     snprintf( buff, sizeof( buff), "Deleted sub : %d (should succeed)", delwin( sub));
-    mvaddstr( 5, 1, buff);
-    snprintf( buff, sizeof( buff), "Deleted win : %d (should succeed,  it doesn't have a subwin now)", delwin( win));
-    mvaddstr( 6, 1, buff);
-    snprintf( buff, sizeof( buff), "Deleted win : %d (should fail,  it'd be a re-deletion)", delwin( win));
-    mvaddstr( 7, 1, buff);
-
-    mvaddstr( 9, 1, "References :");
-    mvaddstr( 10, 1, "https://www.invisible-island.net/ncurses/man/curs_window.3x.html");
-    mvprintw( 11, 1, "https://lists.gnu.org/archive/html/bug-ncurses/2022-08/msg00006.html");
-    mvaddstr( 12, 1, "Hit the any key:");
+    mvaddstr( line++, 1, buff);
+    line++;
+    mvaddstr( line++, 1, "Will now attempt to delete the parent window.  This should succeed,");
+    mvaddstr( line++, 1, "since it no longer has a sub-window.  Hit any key :");
+    getch( );
+    snprintf( buff, sizeof( buff), "Deleted win : %d", delwin( win));
+    mvaddstr( line++, 1, buff);
+    line++;
+    mvaddstr( line++, 1, "Now we'll delete that window again,  which should fail.");
+    mvaddstr( line++, 1, "Hit any key :");
+    getch( );
+    snprintf( buff, sizeof( buff), "Deleted win : %d", delwin( win));
+    mvaddstr( line++, 1, buff);
+    mvaddstr( line++, 1, "And we're done.  Hit any key to exit :");
     getch( );
     endwin( );
     delscreen( screen);