Better security fix for subshell

[Pavel Roskin]

Hello!

It's a reply to myself :-)

> Bash, unlike zsh and tcsh, requires `-e' after `echo'. It also doesn't
> read more that 3 digits in octals. Tcsh and zsh, on the other hand,
> require the first digit to be 0 and allow 4-digit octals.

Many thanks to Francis Kwok <francis.kwok at alcatel.com> who reported within
hours (!!!) that the octals don't work on tcsh compiled for Solaris (it
has echo_style=bsd by default).  "set echo_style=both" is now fed to the
subshell at startup if it happens to be tcsh.

> This patch doesn't deal with passing the current directory name back from
> the subshell. It still can be misinterpreted by mc (try entering directory
> `\\\\')

Fixed.  It's not even related to subshell.  canonicalize_pathname()
refused to canonicalize after a backslashed path separator.  There is no
reason I can think of for this exception (maybe the author of this code
thought that path separators are allowed in the filenames).  The code is
ancient (pre-1998) and has no corresonding record in OChangeLog.  It must
be a long-standing bug.

As you can see, some bugs live hours, some bugs live years.

------------------------------------
--- ChangeLog
+++ ChangeLog
@@ -1 +1,6 @@
+2001-07-13  Pavel Roskin  <proski at gnu.org>
+
+	* utilunix.c (canonicalize_pathname): Don't handle PATH_SEP
+	after backslash	in a special way.
+
 2001-07-12  Pavel Roskin  <proski at gnu.org>
--- utilunix.c
+++ utilunix.c
@@ -637,10 +637,6 @@ char *canonicalize_pathname (char *path)
 	    i = start + 1;
 	}

-        /* Handle backquoted `/'. */
-        if (start > 0 && path[start - 1] == '\\')
-	    continue;
-
         /* Check for trailing `/'. */
         if (start && !path[i]) {
 	zero_last:
------------------------------------

Regards,
Pavel Roskin