master a7057745f5e: Detect the readline support for Python shell completion

[Basil L. Contovounesios]

branch: master
commit a7057745f5ef903a2655c6d9e7813168e361baf7
Author: Liu Hui <liuhui1610@gmail.com>
Commit: Basil L. Contovounesios <basil@contovou.net>

    Detect the readline support for Python shell completion
    
    * lisp/progmodes/python.el
    (python-shell-comint-watch-for-first-prompt-output-filter):
    Detect the readline support.
    (python-shell-readline-completer-delims): Update docstring.
    (python-shell-completion-native-setup): Move the readline
    detection code to ...
    (python-shell-readline-detect): ... new function.
    (python-shell-completion-native-turn-on-maybe): Skip if Python
    has no readline support.
    (python-shell-completion-at-point): Respect the delimiter of
    readline completer in non-native completion.
    * test/lisp/progmodes/python-tests.el
    (python-shell-completion-at-point-1)
    (python-shell-completion-at-point-native-1)
    (python-completion-at-point-1, python-completion-at-point-2)
    (python-completion-at-point-pdb-1)
    (python-completion-at-point-while-running-1)
    (python-completion-at-point-native-1)
    (python-completion-at-point-native-2)
    (python-completion-at-point-native-with-ffap-1)
    (python-completion-at-point-native-with-eldoc-1): Skip tests if
    Python has no readline support.
    (python-shell-completion-at-point-jedi-completer): Add test for
    non-native Python shell completion. (bug#68559)
---
 lisp/progmodes/python.el            | 29 ++++++++++++++++++++++-------
 test/lisp/progmodes/python-tests.el | 31 ++++++++++++++++++++++++++-----
 2 files changed, 48 insertions(+), 12 deletions(-)

diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 1016655cb62..8279617b6e7 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -3601,6 +3601,7 @@ The coding cookie regexp is specified in PEP 263.")
           (python-shell-send-string-no-output 
python-shell-eval-file-setup-code))
         (with-current-buffer (current-buffer)
           (let ((inhibit-quit nil))
+            (python-shell-readline-detect)
             (run-hooks 'python-shell-first-prompt-hook))))))
   output)
 
@@ -4361,7 +4362,23 @@ When a match is found, native completion is disabled."
 
 (defvar python-shell-readline-completer-delims nil
   "Word delimiters used by the readline completer.
-It is automatically set by Python shell.")
+It is automatically set by Python shell.  An empty string means no
+characters are considered delimiters and the readline completion
+considers the entire line of input.  A value of nil means the Python
+shell has no readline support.")
+
+(defun python-shell-readline-detect ()
+  "Detect the readline support for Python shell completion."
+  (let* ((process (python-shell-get-process))
+         (output (python-shell-send-string-no-output "
+try:
+    import readline
+    print(readline.get_completer_delims())
+except:
+    print('No readline support')" process)))
+    (setq-local python-shell-readline-completer-delims
+                (unless (string-search "No readline support" output)
+                  (string-trim-right output)))))
 
 (defvar python-shell-completion-native-redirect-buffer
   " *Python completions redirect*"
@@ -4501,10 +4518,6 @@ def __PYTHON_EL_native_completion_setup():
 __PYTHON_EL_native_completion_setup()" process)))
     (when (string-match-p "python\\.el: native completion setup loaded"
                           output)
-      (setq-local python-shell-readline-completer-delims
-                  (string-trim-right
-                   (python-shell-send-string-no-output
-                    "import readline; 
print(readline.get_completer_delims())")))
       (python-shell-completion-native-try))))
 
 (defun python-shell-completion-native-turn-off (&optional msg)
@@ -4533,7 +4546,8 @@ With argument MSG show activation/deactivation message."
       (cond
        ((python-shell-completion-native-interpreter-disabled-p)
         (python-shell-completion-native-turn-off msg))
-       ((python-shell-completion-native-setup)
+       ((and python-shell-readline-completer-delims
+             (python-shell-completion-native-setup))
         (when msg
           (message "Shell native completion is enabled.")))
        (t
@@ -4705,7 +4719,8 @@ using that one instead of current buffer's process."
                (with-current-buffer (process-buffer process)
                  (if python-shell-completion-native-enable
                      (string= python-shell-readline-completer-delims "")
-                   (string-match-p "ipython[23]?\\'" 
python-shell-interpreter)))))
+                   (or (string-match-p "ipython[23]?\\'" 
python-shell-interpreter)
+                       (equal python-shell-readline-completer-delims ""))))))
          (start
           (if (< (point) line-start)
               (point)
diff --git a/test/lisp/progmodes/python-tests.el 
b/test/lisp/progmodes/python-tests.el
index 1ceee690cfb..e11440cdb5b 100644
--- a/test/lisp/progmodes/python-tests.el
+++ b/test/lisp/progmodes/python-tests.el
@@ -4783,6 +4783,7 @@ def foo():
   (python-tests-with-temp-buffer-with-shell
    ""
    (python-shell-with-shell-buffer
+     (skip-unless python-shell-readline-completer-delims)
      (insert "import abc")
      (comint-send-input)
      (python-tests-shell-wait-for-prompt)
@@ -4797,6 +4798,7 @@ def foo():
    ""
    (python-shell-completion-native-turn-on)
    (python-shell-with-shell-buffer
+     (skip-unless python-shell-readline-completer-delims)
      (insert "import abc")
      (comint-send-input)
      (python-tests-shell-wait-for-prompt)
@@ -4883,11 +4885,14 @@ def foo():
     (python-tests-with-temp-buffer-with-shell
      ""
      (python-shell-with-shell-buffer
-      (python-shell-completion-native-turn-on)
-      (skip-unless (string= python-shell-readline-completer-delims ""))
-      (python-tests--completion-module)
-      (python-tests--completion-parameters)
-      (python-tests--completion-extra-context)))))
+       (skip-unless (string= python-shell-readline-completer-delims ""))
+       (python-shell-completion-native-turn-off)
+       (python-tests--completion-module)
+       (python-tests--completion-parameters)
+       (python-shell-completion-native-turn-on)
+       (python-tests--completion-module)
+       (python-tests--completion-parameters)
+       (python-tests--completion-extra-context)))))
 
 (ert-deftest python-shell-completion-at-point-ipython ()
   "Check if Python shell completion works for IPython."
@@ -4924,6 +4929,8 @@ def foo():
 import abc
 "
    (let ((inhibit-message t))
+     (python-shell-with-shell-buffer
+       (skip-unless python-shell-readline-completer-delims))
      (python-shell-send-buffer)
      (python-tests-shell-wait-for-prompt)
      (goto-char (point-max))
@@ -4940,6 +4947,8 @@ import abc
 import abc
 "
    (let ((inhibit-message t))
+     (python-shell-with-shell-buffer
+       (skip-unless python-shell-readline-completer-delims))
      (python-shell-send-buffer)
      (python-tests-shell-wait-for-prompt)
      (python-shell-with-shell-buffer
@@ -4959,6 +4968,8 @@ pdb.set_trace()
 print('Hello')
 "
    (let ((inhibit-message t))
+     (python-shell-with-shell-buffer
+       (skip-unless python-shell-readline-completer-delims))
      (python-shell-send-buffer)
      (python-tests-shell-wait-for-prompt)
      (goto-char (point-max))
@@ -4975,6 +4986,8 @@ import time
 time.sleep(3)
 "
    (let ((inhibit-message t))
+     (python-shell-with-shell-buffer
+       (skip-unless python-shell-readline-completer-delims))
      (python-shell-send-buffer)
      (goto-char (point-max))
      (insert "time.")
@@ -4987,6 +5000,8 @@ time.sleep(3)
 import abc
 "
    (let ((inhibit-message t))
+     (python-shell-with-shell-buffer
+       (skip-unless python-shell-readline-completer-delims))
      (python-shell-completion-native-turn-on)
      (python-shell-send-buffer)
      (python-tests-shell-wait-for-prompt)
@@ -5004,6 +5019,8 @@ import abc
 import abc
 "
    (let ((inhibit-message t))
+     (python-shell-with-shell-buffer
+       (skip-unless python-shell-readline-completer-delims))
      (python-shell-completion-native-turn-on)
      (python-shell-send-buffer)
      (python-tests-shell-wait-for-prompt)
@@ -5020,6 +5037,8 @@ import abc
 import abc
 "
    (let ((inhibit-message t))
+     (python-shell-with-shell-buffer
+       (skip-unless python-shell-readline-completer-delims))
      (python-shell-completion-native-turn-on)
      (python-shell-send-buffer)
      (python-tests-shell-wait-for-prompt)
@@ -5036,6 +5055,8 @@ import abc
 import abc
 "
    (let ((inhibit-message t))
+     (python-shell-with-shell-buffer
+       (skip-unless python-shell-readline-completer-delims))
      (python-shell-completion-native-turn-on)
      (python-shell-send-buffer)
      (python-tests-shell-wait-for-prompt)