[Bug: 21.5-b27] Query/Replace string starting with TAB character crashes X

[Stephen J. Turnbull]

Dan Krejsa writes:

 > While editing a C header file I use Alt-% to do a Query Replace.
 > If the Query string I enter starts with a tab character, when
 > I hit the Enter key to terminate the Query string, X/Gnome crashes

If a program crashes, it's the program's bug.  X11 is famous for doing
almost no sanity checking on arguments for internal functions; this
kind of crash is a not uncommon result.

>From PROBLEMS (this version has not been released in 21.4 yet):

*** XEmacs and the X server crash when inserting or displaying a TAB character.

If you are using the XFree86 distribution, you need an X server with
this patch applied:

https://bugs.freedesktop.org/attachment.cgi?id=2016

Versions of XFree86 previous to that crashed when an app tried to draw a
literal tab character using many fonts.