[PATCH] ob-core: Fix handling of multiple noweb refs in same line

[Kyle Meyer <kyle@kyleam.com>]

Tom Gillespie writes:

> Hi,
>    The 9.4 release has a bug where it will only tangle the first noweb
> reference on a line.
> This is also present at 9c31cba002a1ba93053aebea1f778be87f61ba06. It happens in
> emacs-27 and emacs-28. The reproduction is below. Best!

Thanks for the report and the reproducer.

This bisects to c1aed9f80 (ob-core: Refactor
`org-babel-expand-noweb-references', 2020-01-12).  The patch below
addresses the case you provided (added as a test) and doesn't cause any
of the other tests to fail.  However, I'm no tangler, so I'd appreciate
if you could give it some testing and report back.

(I should also look more closely at org-babel-expand-noweb-references
before applying and see if I spot anything that suggests this change is
problematic.)

-- >8 --
Subject: [PATCH] ob-core: Fix handling of multiple noweb refs in same line

* lisp/ob-core.el (org-babel-expand-noweb-references): Don't anchor
noweb regexp at start of line to allow multiple matches per line.
* testing/lisp/test-ob-tangle.el (ob-tangle/multiple-noweb-in-line):
Add test.

This fixes a regression introduced by c1aed9f80 (ob-core: Refactor
`org-babel-expand-noweb-references', 2020-01-12), which was part of
the 9.4 release.

Reported-by: Tom Gillespie <tgbugs@gmail.com>
Ref: https://orgmode.org/list/CA+G3_PO2yO1jMMpdrkc39BGQQ2eU5X4FzTEJVotjDJo-50dsqQ@mail.gmail.com
---
 lisp/ob-core.el                |  2 +-
 testing/lisp/test-ob-tangle.el | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/lisp/ob-core.el b/lisp/ob-core.el
index a5e079d9a..7300f239e 100644
--- a/lisp/ob-core.el
+++ b/lisp/ob-core.el
@@ -2781,7 +2781,7 @@ (defun org-babel-expand-noweb-references (&optional info parent-buffer)
          (lang (nth 0 info))
          (body (nth 1 info))
 	 (comment (string= "noweb" (cdr (assq :comments (nth 2 info)))))
-	 (noweb-re (format "^\\(.*?\\)\\(%s\\)"
+	 (noweb-re (format "\\(.*?\\)\\(%s\\)"
 			   (with-current-buffer parent-buffer
 			     (org-babel-noweb-wrap))))
 	 (cache nil)
diff --git a/testing/lisp/test-ob-tangle.el b/testing/lisp/test-ob-tangle.el
index e0e2ea52c..cfdf16d40 100644
--- a/testing/lisp/test-ob-tangle.el
+++ b/testing/lisp/test-ob-tangle.el
@@ -420,6 +420,38 @@ (ert-deftest ob-tangle/commented-src-blocks ()
 		    (org-split-string (buffer-string))))
 	      (delete-file file))))))
 
+(ert-deftest ob-tangle/multiple-noweb-in-line ()
+  "Test handling of multiple noweb references in a single line."
+  (should
+   (equal '("1" "2" "1")
+	  (let ((file (make-temp-file "org-tangle-")))
+	    (unwind-protect
+		(progn
+		  (org-test-with-temp-text-in-file
+		      (format "
+#+name: block1
+#+begin_src elisp
+1
+#+end_src
+
+#+name: block2
+#+begin_src elisp
+2
+#+end_src
+
+#+name: block3
+#+begin_src elisp :noweb yes :tangle %s
+<<block1>> <<block2>> <<block1>>
+#+end_src"
+			      file)
+		    (let ((org-babel-noweb-error-all-langs nil)
+			  (org-babel-noweb-error-langs nil))
+		      (org-babel-tangle)))
+		  (with-temp-buffer
+		    (insert-file-contents file)
+		    (org-split-string (buffer-string))))
+	      (delete-file file))))))
+
 (ert-deftest ob-tangle/detangle-false-positive ()
   "Test handling of false positive link during detangle."
   (let (buffer)

base-commit: e6021bc9b18982b30dd61417d98276b2984892cd
-- 
2.28.0