ob-tangle: Fix `org-babel-tangle-jump-to-org'

* lisp/ob-tangle.el (org-babel-tangle-jump-to-org): Find correct
  location in the Org document.

* testing/lisp/test-ob-tangle.el (ob-tangle/jump-to-org): New test.

lisp/ob-tangle.el

@@ -29,10 +29,13 @@
 (require 'org-src)
 
 (declare-function make-directory "files" (dir &optional parents))
+(declare-function org-at-heading-p "org" (&optional ignored))
 (declare-function org-babel-update-block-body "org" (new-body))
 (declare-function org-back-to-heading "org" (invisible-ok))
 (declare-function org-before-first-heading-p "org" ())
 (declare-function org-edit-special "org" (&optional arg))
+(declare-function org-element-at-point "org-element" ())
+(declare-function org-element-type "org-element" (element))
 (declare-function org-fill-template "org" (template alist))
 (declare-function org-heading-components "org" ())
 (declare-function org-in-commented-heading-p "org" (&optional no-inheritance))
@@ -545,7 +548,7 @@ which enable the original code blocks to be found."
       (prog1 counter (message "Detangled %d code blocks" counter)))))
 
 (defun org-babel-tangle-jump-to-org ()
-  "Jump from a tangled code file to the related Org-mode file."
+  "Jump from a tangled code file to the related Org mode file."
   (interactive)
   (let ((mid (point))
 	start body-start end done
@@ -554,9 +557,8 @@ which enable the original code blocks to be found."
       (save-excursion
 	(while (and (re-search-backward org-bracket-link-analytic-regexp nil t)
 		    (not ; ever wider searches until matching block comments
-		     (and (setq start (point-at-eol))
-			  (setq body-start (save-excursion
-					     (forward-line 2) (point-at-bol)))
+		     (and (setq start (line-beginning-position))
+			  (setq body-start (line-beginning-position 2))
 			  (setq link (match-string 0))
 			  (setq path (match-string 3))
 			  (setq block-name (match-string 5))
@@ -565,29 +567,33 @@ which enable the original code blocks to be found."
 			      (re-search-forward
 			       (concat " " (regexp-quote block-name)
 				       " ends here") nil t)
-			      (setq end (point-at-bol))))))))
+			      (setq end (line-beginning-position))))))))
 	(unless (and start (< start mid) (< mid end))
 	  (error "Not in tangled code"))
-        (setq body (org-babel-trim (buffer-substring start end))))
+        (setq body (buffer-substring body-start end)))
       (when (string-match "::" path)
         (setq path (substring path 0 (match-beginning 0))))
-      (find-file path) (setq target-buffer (current-buffer))
-      (goto-char start) (org-open-link-from-string link)
+      (find-file path)
+      (setq target-buffer (current-buffer))
+      ;; Go to the beginning of the relative block in Org file.
+      (org-open-link-from-string link)
       (if (string-match "[^ \t\n\r]:\\([[:digit:]]+\\)" block-name)
-          (org-babel-next-src-block
-           (string-to-number (match-string 1 block-name)))
+          (let ((n (string-to-number (match-string 1 block-name))))
+	    (if (org-before-first-heading-p) (goto-char (point-min))
+	      (org-back-to-heading t))
+	    ;; Do not skip the first block if it begins at point min.
+	    (cond ((or (org-at-heading-p)
+		       (not (eq (org-element-type (org-element-at-point))
+				'src-block)))
+		   (org-babel-next-src-block n))
+		  ((= n 1))
+		  (t (org-babel-next-src-block (1- n)))))
         (org-babel-goto-named-src-block block-name))
-      ;; position at the beginning of the code block body
       (goto-char (org-babel-where-is-src-block-head))
+      ;; Preserve location of point within the source code in tangled
+      ;; code file.
       (forward-line 1)
-      ;; Use org-edit-special to isolate the code.
-      (org-edit-special)
-      ;; Then move forward the correct number of characters in the
-      ;; code buffer.
       (forward-char (- mid body-start))
-      ;; And return to the Org-mode buffer with the point in the right
-      ;; place.
-      (org-edit-src-exit)
       (setq target-char (point)))
     (org-src-switch-to-buffer target-buffer t)
     (prog1 body (goto-char target-char))))

testing/lisp/test-ob-tangle.el

@@ -36,17 +36,17 @@
 ;;       (org-narrow-to-subtree)
 ;;       (org-babel-tangle target-file))
 ;;     (let ((tang (with-temp-buffer
-;; 		  (insert-file-contents target-file)
-;; 		  (buffer-string))))
+;;                (insert-file-contents target-file)
+;;                (buffer-string))))
 ;;       (flet ((exp-p (arg)
-;; 		    (and
-;; 		     (string-match
-;; 		      (format "noweb-%s-start\\([^\000]*\\)noweb-%s-end" arg arg)
-;; 		      tang)
-;; 		     (string-match "expanded" (match-string 1 tang)))))
-;; 	(should (exp-p "yes"))
-;; 	(should-not (exp-p "no"))
-;; 	(should (exp-p "tangle"))))))
+;;                  (and
+;;                   (string-match
+;;                    (format "noweb-%s-start\\([^\000]*\\)noweb-%s-end" arg arg)
+;;                    tang)
+;;                   (string-match "expanded" (match-string 1 tang)))))
+;;      (should (exp-p "yes"))
+;;      (should-not (exp-p "no"))
+;;      (should (exp-p "tangle"))))))
 
 (ert-deftest ob-tangle/no-excessive-id-insertion-on-tangle ()
   "Don't add IDs to headings without tangling code blocks."
@@ -60,13 +60,13 @@
   "Test that the :noweb-ref header argument is used correctly."
   (org-test-at-id "54d68d4b-1544-4745-85ab-4f03b3cbd8a0"
     (let ((tangled
-	   "df|sed '1d'|awk '{print $5 \" \" $6}'|sort -n |tail -1|awk '{print $2}'"))
+           "df|sed '1d'|awk '{print $5 \" \" $6}'|sort -n |tail -1|awk '{print $2}'"))
       (org-narrow-to-subtree)
       (org-babel-tangle)
       (with-temp-buffer
-	(insert-file-contents "babel.sh")
-	(goto-char (point-min))
-	(should (re-search-forward (regexp-quote tangled) nil t)))
+        (insert-file-contents "babel.sh")
+        (goto-char (point-min))
+        (should (re-search-forward (regexp-quote tangled) nil t)))
       (delete-file "babel.sh"))))
 
 (ert-deftest ob-tangle/expand-headers-as-noweb-references ()
@@ -78,21 +78,21 @@
       (should (string-match (regexp-quote "length 14") expanded)))))
 
 (ert-deftest ob-tangle/comment-links-at-left-margin ()
-    "Test commenting of links at left margin."
+  "Test commenting of links at left margin."
   (should
    (string-match
     (regexp-quote "# [[http://orgmode.org][Org mode]]")
     (org-test-with-temp-text-in-file
-	"[[http://orgmode.org][Org mode]]
+        "[[http://orgmode.org][Org mode]]
 #+header: :comments org :tangle \"test-ob-tangle.sh\"
 #+begin_src sh
 echo 1
 #+end_src"
       (unwind-protect
-	  (progn (org-babel-tangle)
-		 (with-temp-buffer (insert-file-contents "test-ob-tangle.sh")
-				   (buffer-string)))
-	(delete-file "test-ob-tangle.sh"))))))
+          (progn (org-babel-tangle)
+                 (with-temp-buffer (insert-file-contents "test-ob-tangle.sh")
+                                   (buffer-string)))
+        (delete-file "test-ob-tangle.sh"))))))
 
 (ert-deftest ob-tangle/comment-links-numbering ()
   "Test numbering of source blocks when commenting with links."
@@ -109,16 +109,92 @@ echo 1
 2
 #+end_src"
      (unwind-protect
-	 (progn
-	   (org-babel-tangle)
-	   (with-temp-buffer
-	     (insert-file-contents "test-ob-tangle.el")
-	     (buffer-string)
-	     (goto-char (point-min))
-	     (and (search-forward "[H:1]]" nil t)
-		  (search-forward "[H:2]]" nil t))))
+         (progn
+           (org-babel-tangle)
+           (with-temp-buffer
+             (insert-file-contents "test-ob-tangle.el")
+             (buffer-string)
+             (goto-char (point-min))
+             (and (search-forward "[H:1]]" nil t)
+                  (search-forward "[H:2]]" nil t))))
        (delete-file "test-ob-tangle.el")))))
 
+(ert-deftest ob-tangle/jump-to-org ()
+  "Test `org-babel-tangle-jump-to-org' specifications."
+  ;; Standard test.
+  (should
+   (equal
+    "* H\n#+begin_src emacs-lisp\n1\n#+end_src"
+    (org-test-with-temp-text-in-file
+        "* H\n#+begin_src emacs-lisp\n1\n#+end_src"
+      (let ((file (buffer-file-name)))
+        (org-test-with-temp-text
+            (format ";; [[file:%s][H:1]]\n<point>1\n;; H:1 ends here\n"
+                    (file-name-nondirectory file))
+          (org-babel-tangle-jump-to-org)
+          (buffer-string))))))
+  ;; Multiple blocks in the same section.
+  (should
+   (equal
+    "2"
+    (org-test-with-temp-text-in-file
+        "* H
+
+first block
+
+#+begin_src emacs-lisp
+1
+#+end_src
+
+another block
+
+#+begin_src emacs-lisp
+2
+#+end_src
+"
+      (let ((file (buffer-file-name)))
+        (org-test-with-temp-text
+            (format ";; [[file:%s][H:2]]\n<point>2\n;; H:2 ends here\n"
+                    (file-name-nondirectory file))
+          (org-babel-tangle-jump-to-org)
+          (buffer-substring (line-beginning-position)
+                            (line-end-position)))))))
+  ;; Preserve position within the source code.
+  (should
+   (equal
+    "1)"
+    (org-test-with-temp-text-in-file
+        "* H\n#+begin_src emacs-lisp\n(+ 1 1)\n#+end_src"
+      (let ((file (buffer-file-name)))
+        (org-test-with-temp-text
+            (format ";; [[file:%s][H:1]]\n(+ 1 <point>1)\n;; H:1 ends here\n"
+                    (file-name-nondirectory file))
+          (org-babel-tangle-jump-to-org)
+          (buffer-substring-no-properties (point) (line-end-position)))))))
+  ;; Blocks before first heading.
+  (should
+   (equal
+    "Buffer start\n#+begin_src emacs-lisp\n1\n#+end_src\n* H"
+    (org-test-with-temp-text-in-file
+        "Buffer start\n#+begin_src emacs-lisp\n1\n#+end_src\n* H"
+      (let ((file (buffer-file-name)))
+        (org-test-with-temp-text
+            (format ";; [[file:%s][H:1]]\n<point>1\n;; H:1 ends here\n"
+                    (file-name-nondirectory file))
+          (org-babel-tangle-jump-to-org)
+          (buffer-string))))))
+  ;; Special case: buffer starts with a source block.
+  (should
+   (equal
+    "#+begin_src emacs-lisp\n1\n#+end_src\n* H"
+    (org-test-with-temp-text-in-file
+        "#+begin_src emacs-lisp\n1\n#+end_src\n* H"
+      (let ((file (buffer-file-name)))
+        (org-test-with-temp-text
+            (format ";; [[file:%s][H:1]]\n<point>1\n;; H:1 ends here\n"
+                    (file-name-nondirectory file))
+          (org-babel-tangle-jump-to-org)
+          (buffer-string)))))))
 
 (provide 'test-ob-tangle)