babel: safer modification of `call-process-region'

contrib/babel/lisp/org-babel.el

@@ -226,27 +226,28 @@ block."
 	  (if (boundp 'call-process-region-original) call-process-region-original
 	    (symbol-function 'call-process-region)))
          result)
-    ;; (message "params=%S" params) ;; debugging
-    (flet ((call-process-region (&rest args)
-				(apply 'org-babel-tramp-handle-call-process-region args)))
-      (unless (member lang org-babel-interpreters)
-	(error "Language is not in `org-babel-interpreters': %s" lang))
-      (if (and (not arg) new-hash (equal new-hash old-hash))
-	  (save-excursion ;; return cached result
-	    (goto-char (org-babel-where-is-src-block-result nil info))
-	    (move-end-of-line 1) (forward-char 1)
-	    (setq result (org-babel-read-result))
-	    (message (replace-regexp-in-string "%" "%%" (format "%S" result))) result)
-	(setq result (funcall cmd body params))
-	(if (eq result-type 'value)
-	    (setq result (if (and (or (member "vector" result-params)
-				      (member "table" result-params))
-				  (not (listp result)))
-			     (list (list result))
-			   result)))
-	(org-babel-insert-result result result-params info new-hash)
-	(run-hooks 'org-babel-after-execute-hook)
-	result))))
+    (unwind-protect
+        (flet ((call-process-region (&rest args)
+                                    (apply 'org-babel-tramp-handle-call-process-region args)))
+          (unless (member lang org-babel-interpreters)
+            (error "Language is not in `org-babel-interpreters': %s" lang))
+          (if (and (not arg) new-hash (equal new-hash old-hash))
+              (save-excursion ;; return cached result
+                (goto-char (org-babel-where-is-src-block-result nil info))
+                (move-end-of-line 1) (forward-char 1)
+                (setq result (org-babel-read-result))
+                (message (replace-regexp-in-string "%" "%%" (format "%S" result))) result)
+            (setq result (funcall cmd body params))
+            (if (eq result-type 'value)
+                (setq result (if (and (or (member "vector" result-params)
+                                          (member "table" result-params))
+                                      (not (listp result)))
+                                 (list (list result))
+                               result)))
+            (org-babel-insert-result result result-params info new-hash)
+            (run-hooks 'org-babel-after-execute-hook)
+            result))
+      (setq call-process-region 'call-process-region-original))))
 
 (defun org-babel-load-in-session (&optional arg info)
   "Load the body of the current source-code block.  Evaluate the