From: Paul Eggert Date: Thu, 28 Apr 2022 17:51:01 +0000 (-0700) Subject: Document \807 etc. in raw byte display X-Git-Tag: archive/raspbian/1%29.2+1-2+rpi1^2~5^2~16^2~2370^2~232 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=a41a181db5f3aca043ed42b228dc56a6403c21a5;p=emacs.git Document \807 etc. in raw byte display * doc/emacs/display.texi (Display Custom): Mention potential confusion in raw byte display. --- diff --git a/doc/emacs/display.texi b/doc/emacs/display.texi index 2ac0dca6223..7a6c7f391b9 100644 --- a/doc/emacs/display.texi +++ b/doc/emacs/display.texi @@ -2097,3 +2097,14 @@ argument to suppress the effect of bold-face in this case. byte with a decimal value of 128 is displayed as @code{\200}. To change display to the hexadecimal format of @code{\x80}, set the variable @code{display-raw-bytes-as-hex} to @code{t}. +Care may be needed when interpreting a raw byte when copying +text from a terminal containing an Emacs session, or when a terminal's +@code{escape-glyph} face looks like the default face. For example, by +default Emacs displays the four characters @samp{\}, @samp{2}, +@samp{0}, @samp{0} with the same characters it displays a byte with +decimal value 128. The problem can be worse with hex displays, where +the raw byte 128 followed by the character @samp{7} is displayed as +@code{\x807}, which Emacs Lisp reads as the single character U+0807 +SAMARITAN LETTER IT; this confusion does not occur with the +corresponding octal display @code{\2007} because octal escapes contain +at most three digits.