Re: [babel] [BUG] incorrect indentation when tangling with org-src-preserve-indentation

[Antti Kaihola <akaihola@gmail.com>]

Here's another stab at fixing the problem. This one enhances the
existing trimming algorithm by preserving any leading whitespace on
the first non-blank line of a block. This probably breaks tangling of
other languages than Python, but someone more familiar with the babel
codebase will be able to come up with a saner solution.


diff --git a/lisp/ob-python.el b/lisp/ob-python.el
index c172756..39665c2 100644
--- a/lisp/ob-python.el
+++ b/lisp/ob-python.el
@@ -58,3 +58,3 @@
     (nth 1 (or processed-params (org-babel-process-params params))) "\n")
-   "\n" (org-babel-trim body) "\n"))
+   "\n" (org-babel-indent-safe-trim body) "\n"))

diff --git a/lisp/ob-tangle.el b/lisp/ob-tangle.el
index 3a0426a..e619e90 100644
--- a/lisp/ob-tangle.el
+++ b/lisp/ob-tangle.el
@@ -368,3 +368,3 @@ form
       (insert (format "%s\n" (replace-regexp-in-string
-			      "^," "" (org-babel-trim body))))
+			      "^," "" (org-babel-indent-safe-trim body))))
       (when link-p
diff --git a/lisp/ob.el b/lisp/ob.el
index b05100c..9d750e7 100644
--- a/lisp/ob.el
+++ b/lisp/ob.el
@@ -1723,2 +1723,9 @@ overwritten by specifying a regexp as a second argument."

+(defun org-babel-indent-safe-trim (string)
+  "Strip leading and trailing spaces and carriage returns from STRING.
+Like `org-babel-chomp' only it runs on both the front and back
+of the string. Preserves leading tabs and spaces on first non-blank line."
+  (string-match "\\`\\(?:[ \f\t\n\r\v]*\n\\)?\\(\\(?:\n?.*?\\)*?\\)[
\f\t\n\r\v]*\\'" string)
+  (match-string 1 string))
+
 (defun org-babel-trim (string &optional regexp)