Re: Async Python src block behavior with :dir header property

[Ihor Radchenko]

Jack Kamm <jackkamm@gmail.com> writes:

> On executing any python session block I am getting the following error
> which I think is caused by the above:
>
>   Debugger entered--Lisp error: (void-variable buffer-name)

That's a mystery.

> Also, make shows a byte-compiler warning about this:
>
>   Compiling 
> /home/jack/src/org-mode/2024-01-async-file-results-dir/lisp/ob-core.el...
>   
>   In org-babel-session-buffer:
>   ob-core.el:785:15: Warning: reference to free variable ‘buffer-name’

But this is a real problem.
See the attached updated version of the patch set.

>From 1185e7a3569048b465b697fe173ce50a3ab7f0cc Mon Sep 17 00:00:00 2001
Message-ID: 
<1185e7a3569048b465b697fe173ce50a3ab7f0cc.1707406936.git.yantar92@posteo.net>
From: Ihor Radchenko <yantar92@posteo.net>
Date: Sat, 3 Feb 2024 16:47:57 +0100
Subject: [PATCH v2 1/3] org-babel-execute-src-block: Force :dir according to
 live session

* lisp/ob-core.el (org-babel-execute-src-block): Force eval directory
to follow live session buffer, if any.  This is consistent with what
we promise in the manual section "16.4 Environment of a Code
Block">Choosing a working directory.

Link: 87mssi8ht2.fsf@gmail.com">https://orgmode.org/list/87mssi8ht2.fsf@gmail.com
---
 lisp/ob-core.el | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/lisp/ob-core.el b/lisp/ob-core.el
index 1de3af6ad..fd8d06c5d 100644
--- a/lisp/ob-core.el
+++ b/lisp/ob-core.el
@@ -840,14 +840,17 @@ (defun org-babel-execute-src-block (&optional arg info 
params executor-type)
                 (dir (cdr (assq :dir params)))
                 (mkdirp (cdr (assq :mkdirp params)))
                 (default-directory
-                  (cond
-                   ((not dir) default-directory)
-                   ((member mkdirp '("no" "nil" nil))
-                    (file-name-as-directory (expand-file-name dir)))
-                   (t
-                    (let ((d (file-name-as-directory (expand-file-name dir))))
-                      (make-directory d 'parents)
-                      d))))
+                 (cond
+                  ((not dir) default-directory)
+                   ((when-let ((session (cdr (assq :session params))))
+                      (when (org-babel-comint-buffer-livep session)
+                        (buffer-local-value 'default-directory (get-buffer 
session)))))
+                  ((member mkdirp '("no" "nil" nil))
+                   (file-name-as-directory (expand-file-name dir)))
+                  (t
+                   (let ((d (file-name-as-directory (expand-file-name dir))))
+                     (make-directory d 'parents)
+                     d))))
                 (cmd (intern (concat "org-babel-execute:" lang)))
                 result exec-start-time)
            (unless (fboundp cmd)
-- 
2.43.0

>From 8799d747ab2983f43dab117713342dbc92c6fc16 Mon Sep 17 00:00:00 2001
Message-ID: 
<8799d747ab2983f43dab117713342dbc92c6fc16.1707406936.git.yantar92@posteo.net>
In-Reply-To: 
<1185e7a3569048b465b697fe173ce50a3ab7f0cc.1707406936.git.yantar92@posteo.net>
References: 
<1185e7a3569048b465b697fe173ce50a3ab7f0cc.1707406936.git.yantar92@posteo.net>
From: Jack Kamm <jackkamm@gmail.com>
Date: Wed, 31 Jan 2024 20:06:00 -0800
Subject: [PATCH v2 2/3] ob-comint: Make file results from async sessions
 respect :dir header

* lisp/ob-comint.el (org-babel-comint-async-filter): Set
default-directory before calling `org-babel-insert-result'

https://list.orgmode.org/875xz9o4nj.fsf@localhost/T/#t
---
 lisp/ob-comint.el | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lisp/ob-comint.el b/lisp/ob-comint.el
index 7d258ea0e..349524701 100644
--- a/lisp/ob-comint.el
+++ b/lisp/ob-comint.el
@@ -224,6 +224,8 @@ (defun org-babel-comint-async-filter (string)
         (file-callback org-babel-comint-async-file-callback)
         (combined-string (concat org-babel-comint-async-dangling string))
         (new-dangling combined-string)
+         ;; Assumes comint filter called with session buffer current
+         (session-dir default-directory)
         ;; list of UUID's matched by `org-babel-comint-async-indicator'
         uuid-list)
     (with-temp-buffer
@@ -248,7 +250,8 @@ (defun org-babel-comint-async-filter (string)
                                 (let* ((info (org-babel-get-src-block-info))
                                        (params (nth 2 info))
                                        (result-params
-                                        (cdr (assq :result-params params))))
+                                        (cdr (assq :result-params params)))
+                                       (default-directory session-dir))
                                   (org-babel-insert-result
                                    (funcall file-callback
                                             (nth
@@ -291,7 +294,8 @@ (defun org-babel-comint-async-filter (string)
                                    (let* ((info (org-babel-get-src-block-info))
                                           (params (nth 2 info))
                                           (result-params
-                                           (cdr (assq :result-params params))))
+                                           (cdr (assq :result-params params)))
+                                          (default-directory session-dir))
                                     (org-babel-insert-result
                                       res-str result-params info))
                                   t))))
-- 
2.43.0

>From 0d496b8fcc205810c994b32b2ab732305a4d9a26 Mon Sep 17 00:00:00 2001
Message-ID: 
<0d496b8fcc205810c994b32b2ab732305a4d9a26.1707406936.git.yantar92@posteo.net>
In-Reply-To: 
<1185e7a3569048b465b697fe173ce50a3ab7f0cc.1707406936.git.yantar92@posteo.net>
References: 
<1185e7a3569048b465b697fe173ce50a3ab7f0cc.1707406936.git.yantar92@posteo.net>
From: Ihor Radchenko <yantar92@posteo.net>
Date: Tue, 6 Feb 2024 15:02:48 +0100
Subject: [PATCH v2 3/3] org-babel: New babel backend API function
 org-babel-session-buffer:<lang>

* lisp/ob-core.el (org-babel-session-buffer): New API function that
return session buffer, if such buffer exists and is live.
(org-babel-execute-src-block): Use `org-babel-session-buffer'.
* lisp/ob-lua.el (org-babel-session-buffer:lua):
* lisp/ob-python.el (org-babel-session-buffer:python): Provide API to
retrieve session buffer name.
(org-babel-python-initiate-session-by-key): Use
`org-babel-session-buffer:python'.
* etc/ORG-NEWS (Org babel backends are now expected to define an
additional API function ~org-babel-session-buffer:<lang>~): Declare
the API addition.

Link: https://orgmode.org/list/87r0hr9f3b.fsf@localhost
---
 etc/ORG-NEWS      | 11 +++++++++++
 lisp/ob-core.el   | 31 ++++++++++++++++++++++++++-----
 lisp/ob-lua.el    |  5 +++++
 lisp/ob-python.el |  8 ++++++--
 4 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 92d363b80..7ac56702d 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -13,6 +13,17 @@ Please send Org bug reports to mailto:emacs-orgmode@gnu.org.
 
 * Version 9.7 (not released yet)
 ** Important announcements and breaking changes
+*** Org babel backends are now expected to define an additional API function 
~org-babel-session-buffer:<lang>~
+
+Org babel now uses session buffer (if it exists) to retrieve
+~default-directory~ environment during src block evaluation.
+
+By default, buffer named like session is checked.  All the backends
+that create sessions inside buffers named differently should provide a
+function ~org-babel-session-buffer:<lang>~.  The function must accept
+two arguments - session name and info list (as returned by
+~org-babel-get-src-block-info~); and return the session buffer name.
+
 *** Org mode now fontifies whole table lines (including newline) according to 
~org-table~ face
 
 Previously, leading indentation and trailing newline in table rows
diff --git a/lisp/ob-core.el b/lisp/ob-core.el
index fd8d06c5d..bfeac257b 100644
--- a/lisp/ob-core.el
+++ b/lisp/ob-core.el
@@ -767,8 +767,30 @@ (defun org-babel--file-desc (params result)
     (`(:file-desc) result)
     (`(:file-desc . ,(and (pred stringp) val)) val)))
 
-(defvar *this*) ; Dynamically bound in `org-babel-execute-src-block'
-                ; and `org-babel-read'
+(defvar *this*)
+;; Dynamically bound in `org-babel-execute-src-block'
+;; and `org-babel-read'
+
+(defun org-babel-session-buffer (&optional info)
+  "Return buffer name for session associated with current code block.
+Return nil when no such live buffer with process exists.
+When INFO is non-nil, it should be a list returned by
+`org-babel-get-src-block-info'.
+This function uses org-babel-session-buffer:<lang> function to
+retrieve backend-specific session buffer name."
+  (declare-function org-babel-comint-buffer-livep "ob-comint" (buffer))
+  (when-let* ((info (or info (org-babel-get-src-block-info 'no-eval)))
+              (lang (nth 0 info))
+              (session (cdr (assq :session (nth 2 info))))
+              (cmd (intern (concat "org-babel-session-buffer:" lang)))
+              (buffer-name
+               (if (fboundp cmd)
+                   (funcall cmd session info)
+                 ;; Use session name as buffer name by default.
+                 session)))
+    (require 'ob-comint)
+    (when (org-babel-comint-buffer-livep buffer-name)
+      buffer-name)))
 
 ;;;###autoload
 (defun org-babel-execute-src-block (&optional arg info params executor-type)
@@ -842,9 +864,8 @@ (defun org-babel-execute-src-block (&optional arg info 
params executor-type)
                 (default-directory
                  (cond
                   ((not dir) default-directory)
-                   ((when-let ((session (cdr (assq :session params))))
-                      (when (org-babel-comint-buffer-livep session)
-                        (buffer-local-value 'default-directory (get-buffer 
session)))))
+                   ((when-let ((session (org-babel-session-buffer info)))
+                      (buffer-local-value 'default-directory (get-buffer 
session))))
                   ((member mkdirp '("no" "nil" nil))
                    (file-name-as-directory (expand-file-name dir)))
                   (t
diff --git a/lisp/ob-lua.el b/lisp/ob-lua.el
index a2b830ca3..b241fccdc 100644
--- a/lisp/ob-lua.el
+++ b/lisp/ob-lua.el
@@ -184,6 +184,11 @@ (defun org-babel-lua-with-earmuffs (session)
        name
       (format "*%s*" name))))
 
+(defun org-babel-session-buffer:lua (session &optional _)
+  "Return session buffer name for SESSION."
+  (or (org-babel-lua-session-buffer session)
+      (org-babel-lua-with-earmuffs session)))
+
 (defun org-babel-lua-without-earmuffs (session)
 "Remove stars around *SESSION*, leaving SESSION."
   (let ((name (if (stringp session) session (format "%s" session))))
diff --git a/lisp/ob-python.el b/lisp/ob-python.el
index cfc0fdcb6..89cdf4c47 100644
--- a/lisp/ob-python.el
+++ b/lisp/ob-python.el
@@ -260,6 +260,11 @@ (defun org-babel-python-without-earmuffs (session)
        (substring name 1 (- (length name) 1))
       name)))
 
+(defun org-babel-session-buffer:python (session &optional _)
+  "Return session buffer name for SESSION."
+  (or (org-babel-python-session-buffer session)
+      (org-babel-python-with-earmuffs session)))
+
 (defun org-babel-python--python-util-comint-end-of-output-p ()
   "Return non-nil if the last prompt matches input prompt.
 Backport of `python-util-comint-end-of-output-p' to emacs28.  To
@@ -302,8 +307,7 @@ (defun org-babel-python-initiate-session-by-key (&optional 
session)
 initialized session."
   (save-window-excursion
     (let* ((session (if session (intern session) :default))
-           (py-buffer (or (org-babel-python-session-buffer session)
-                          (org-babel-python-with-earmuffs session)))
+           (py-buffer (org-babel-session-buffer:python session))
            (python-shell-buffer-name
            (org-babel-python-without-earmuffs py-buffer))
            (existing-session-p (comint-check-proc py-buffer))
-- 
2.43.0

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>