Replace `iff' in doc-strings and comments.

[bpt/emacs.git] / lisp / image.el

diff --git a/lisp/image.el b/lisp/image.el
index 22fa704..480b561 100644 (file)
--- a/lisp/image.el
+++ b/lisp/image.el
@@ -10,7 +10,7 @@
 
 ;; GNU Emacs is free software; you can redistribute it and/or modify
 ;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 2, or (at your option)
+;; the Free Software Foundation; either version 3, or (at your option)
 ;; any later version.
 
 ;; GNU Emacs is distributed in the hope that it will be useful,
@@ -65,13 +65,16 @@ a non-nil value, TYPE is the image's type.")
 When the name of an image file match REGEXP, it is assumed to
 be of image type IMAGE-TYPE.")
 
+;; We rely on `auto-mode-alist' to detect xbm and xpm files, instead
+;; of content autodetection.  Their contents are just C code, so it is
+;; easy to generate false matches.
 (defvar image-type-auto-detectable
   '((pbm . t)
-    (xbm . t)
+    (xbm . nil)
     (bmp . maybe)
     (gif . maybe)
     (png . maybe)
-    (xpm . maybe)
+    (xpm . nil)
     (jpeg . maybe)
     (tiff . maybe)
     (postscript . nil))
@@ -339,16 +342,16 @@ Image types are symbols like `xbm' or `jpeg'."
 
 ;;;###autoload
 (defun image-type-auto-detected-p ()
-  "Return t iff the current buffer contains an auto-detectable image.
-Whether image types are auto-detectable or not depends on the setting
-of the variable `image-type-auto-detectable'.
+  "Return t if the current buffer contains an auto-detectable image.
+This function is intended to be used from `magic-fallback-mode-alist'.
 
-This function is intended to be used from `magic-mode-alist' (which see)."
+The buffer is considered to contain an auto-detectable image if
+its beginning matches an image type in `image-type-header-regexps',
+and that image type is present in `image-type-auto-detectable'."
   (let* ((type (image-type-from-buffer))
         (auto (and type (cdr (assq type image-type-auto-detectable)))))
     (and auto
-        (or (eq auto t)
-            (image-type-available-p type)))))
+        (or (eq auto t) (image-type-available-p type)))))
 
 
 ;;;###autoload