bug#17752: 24.4.50; Scrolling other window while skeleton reads input inserts garbage

[Matthias Meulien <orontee@gmail.com>]

Hi Lars,

Thanks for your time.
 
> Could you provide a step-by-step recipe, starting from "emacs 
> -Q"?

Steps to reproduce (I am now using GNU Emacs 28.0.50 (build 29, 
x86_64-pc-linux-gnu, GTK+ Version 3.24.5, cairo version 1.16.0) of 
2020-11-21), commit 789ee3e1d5 from master:  1. M-x find-file 
/usr/lib/python3.7/copy.py RET 

2. C-x C-w ~/test.py RET 

3. C-v C-v C-u 15 C-n <= scroll two pages and reach an blank line 
where 
   inserting a new class definition makes sense 

4. M-x python-skeleton-class 

6. C-M-S-v

7. C-M-S-v 

8. Test <= I wrote this in the minibuffer where I was prompted 
since 
   step 4 for a class name as required by python-skeleton-class 

7. Press RET  Now the diff of the resulting file is the following. 
As you can see it's not the expected result of 
python-skeleton-class.   --- /usr/lib/python3.7/copy.py	2020-07-25 
15:03:44.000000000 +0200 +++ /home/matthias/test.py	2020-12-05 
17:53:35.503140351 +0100 @@ -46,6 +46,10 @@ 
 to control pickling: they can define methods called 
 __getinitargs__(), __getstate__() and __setstate__().  See the 
 documentation for module "pickle" for information on these 
 methods. 
+Test: +"""""" + + 
 """  import types 
@@ -105,7 +109,7 @@ 
         return x 
     return _reconstruct(x, None, *rv) 
  
- +class  
 _copy_dispatch = d = {}  def _copy_immutable(x): 
 
Diff finished.  Sat Dec  5 17:53:44 2020 

Feel free to ask if it's still unclear.

Regards,
-- 
Matthias