master 5a10e6377c 1/2: Make Python evaluation work more reliably

[Lars Ingebrigtsen]

branch: master
commit 5a10e6377c2b97420e5617f114bb374d67ec1a58
Author: Jin Choi <jsc@alum.mit.edu>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Make Python evaluation work more reliably
    
    * lisp/progmodes/python.el (python-shell-buffer-substring): Make
    more regions valid Python code (bug#55174).
    
    Copyright-paperwork-exempt: yes
---
 lisp/progmodes/python.el            | 23 +++++++++++++----------
 test/lisp/progmodes/python-tests.el | 18 +++---------------
 2 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index b7914655aa..11ed732d28 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -3292,22 +3292,25 @@ the python shell:
                               (goto-char start)
                               (python-util-forward-comment 1)
                               (current-indentation))))
-         (fillstr (and (not no-cookie)
-                       (not starts-at-point-min-p)
-                       (concat
-                        (format "# -*- coding: %s -*-\n" encoding)
-                        (make-string
-                         ;; Subtract 2 because of the coding cookie.
-                         (- (line-number-at-pos start) 2) ?\n)))))
+         (fillstr (cond (starts-at-point-min-p
+                         nil)
+                        ((not no-cookie)
+                         (concat
+                          (format "# -*- coding: %s -*-\n" encoding)
+                          (make-string
+                           ;; Subtract 2 because of the coding cookie.
+                           (- (line-number-at-pos start) 2) ?\n)))
+                        (t
+                         (make-string (- (line-number-at-pos start) 1) ?\n)))))
     (with-temp-buffer
       (python-mode)
       (when fillstr
         (insert fillstr))
-      (insert substring)
-      (goto-char (point-min))
       (when (not toplevel-p)
-        (insert "if True:")
+        (forward-line -1)
+        (insert "if True:\n")
         (delete-region (point) (line-end-position)))
+      (insert substring)
       (when nomain
         (let* ((if-name-main-start-end
                 (and nomain
diff --git a/test/lisp/progmodes/python-tests.el 
b/test/lisp/progmodes/python-tests.el
index 1a6a7dc176..01b233cc42 100644
--- a/test/lisp/progmodes/python-tests.el
+++ b/test/lisp/progmodes/python-tests.el
@@ -3503,10 +3503,7 @@ def foo():
    (should (string= (python-shell-buffer-substring
                      (python-tests-look-at "print ('a')")
                      (point-max))
-                    "if True:
-
-    print ('a')
-"))))
+                    "# -*- coding: utf-8 -*-\nif True:\n    print 
('a')\n\n"))))
 
 (ert-deftest python-shell-buffer-substring-11 ()
   "Check substring from partial block and point within indentation."
@@ -3521,10 +3518,7 @@ def foo():
                        (backward-char 1)
                        (point))
                      (point-max))
-                    "if True:
-
-    print ('a')
-"))))
+                    "# -*- coding: utf-8 -*-\nif True:\n    print 
('a')\n\n"))))
 
 (ert-deftest python-shell-buffer-substring-12 ()
   "Check substring from partial block and point in whitespace."
@@ -3539,13 +3533,7 @@ def foo():
    (should (string= (python-shell-buffer-substring
                      (python-tests-look-at "# Whitespace")
                      (point-max))
-                    "if True:
-
-
-        # Whitespace
-
-    print ('a')
-"))))
+                    "# -*- coding: utf-8 -*-\n\nif True:\n        # 
Whitespace\n\n    print ('a')\n\n"))))