(coding-system-change-eol-coding): New function.

(coding-system-change-text-coding): New function.

1 files changed, 40 insertions, 0 deletions

diff --git a/lisp/international/mule-util.el b/lisp/international/mule-util.el
index a2b534ada28..38178be30b0 100644
--- a/lisp/international/mule-util.el
+++ b/lisp/international/mule-util.el
@@ -288,6 +288,46 @@ or one is an alias of the other."
                  (and (vectorp eol-type-1) (vectorp eol-type-2)))))))
 
 ;;;###autoload
+(defun coding-system-change-eol-conversion (coding-system eol-type)
+  "Return a coding system which differs from CODING-SYSTEM in eol conversion.
+The returned coding system converts end-of-line by EOL-TYPE
+but text as the same way as CODING-SYSTEM.
+EOL-TYPE should be `unix', `dos', `mac', or nil.
+If EOL-TYPE is nil, the returned coding system detects
+how end-of-line is formatted automatically while decoding."
+  (let ((eol-type (cond ((eq eol-type 'unix) 0)
+                        ((eq eol-type 'dos) 1)
+                        ((eq eol-type 'mac) 2)
+                        (t eol-type)))
+        (orig-eol-type (coding-system-eol-type coding-system)))
+    (if (vectorp orig-eol-type)
+        (if (not eol-type)
+            coding-system
+          (aref orig-eol-type eol-type))
+      (let ((base (coding-system-base coding-system)))
+        (if (not eol-type)
+            base
+          (if (= eol-type orig-eol-type)
+              coding-system
+            (setq orig-eol-type (coding-system-eol-type base))
+            (if (vectorp orig-eol-type)
+                (aref orig-eol-type eol-type))))))))
+
+;;;###autoload
+(defun coding-system-change-text-conversion (coding-system coding)
+  "Return a coding system which differs from CODING-SYSTEM in text conversion.
+The returned coding system converts text by CODING
+but end-of-line as the same way as CODING-SYSTEM.
+If CODING is nil, the returned coding system detects
+how text is formatted automatically while decoding."
+  (if (not coding)
+      (coding-system-base coding-system)
+    (let ((eol-type (coding-system-eol-type coding-system)))
+      (coding-system-change-eol-conversion
+       coding
+       (if (numberp eol-type) (aref [unix dos mac] eol-type))))))
+
+;;;###autoload
 (defmacro detect-coding-with-priority (from to priority-list)
   "Detect a coding system of the text between FROM and TO with PRIORITY-LIST.
 PRIORITY-LIST is an alist of coding categories vs the corresponding