(Recognize Coding): Document the variable inhibit-iso-escape-detection.

1 files changed, 24 insertions, 0 deletions

diff --git a/man/mule.texi b/man/mule.texi
index 021bd6d290e..89d46cd1683 100644
--- a/man/mule.texi
+++ b/man/mule.texi
@@ -576,6 +576,7 @@ a regular expression that determines which files this applies to, and
 the third argument says which coding system to use for these files.
 
 @vindex inhibit-eol-conversion
+@cindex DOS-style end-of-line display
   Emacs recognizes which kind of end-of-line conversion to use based on
 the contents of the file: if it sees only carriage-returns, or only
 carriage-return linefeed sequences, then it chooses the end-of-line
@@ -583,6 +584,29 @@ conversion accordingly.  You can inhibit the automatic use of
 end-of-line conversion by setting the variable @code{inhibit-eol-conversion}
 to non-@code{nil}.
 
+@vindex inhibit-iso-escape-detection
+@cindex escape sequences in files
+  By default, the automatic detection of coding system is sensitive to
+escape sequences.  If Emacs sees a sequence of characters that begin
+with an @key{ESC} character, and the sequence is valid as an ISO-2022
+code, the code is determined as one of ISO-2022 encoding, and the file
+is decoded by the corresponding coding system
+(e.g. @code{iso-2022-7bit}).
+
+  However, there may be cases that you want to read escape sequences in
+a file as is.  In such a case, you can set th variable
+@code{inhibit-iso-escape-detection} to non-@code{nil}.  Then the code
+detection will ignore any escape sequences, and so no file is detected
+as being encoded in some of ISO-2022 encoding.  The result is that all
+escape sequences become visible in a buffer.
+
+  The default value of @code{inhibit-iso-escape-detection} is
+@code{nil}, and it is strongly recommended not to change it.  That's
+because many Emacs Lisp source files that contain non-ASCII characters
+are encoded in the coding system @code{iso-2022-7bit} in the Emacs
+distribution, and they won't be decoded correctly when you visit those
+files if you suppress the escape sequence detection.
+
 @vindex coding
   You can specify the coding system for a particular file using the
 @samp{-*-@dots{}-*-} construct at the beginning of a file, or a local