Patch from Stewart Brodie <stewart.brodie@pace.co.uk> to fix ash:

When alias support is not configured, ash believes that command parameters
that look like dd's "if=/dev/zero" are requests to set a temporary
environment variable whilst dd is running, even though it appears after the
command name.  This is caused by the re-use of the checkalias global variable
to indicate when both alias checking and environment variable checking.  The
failure to reset this flag is due to the reset action being performed only
inside the feature check CHECK_ASH_ALIAS.  Hence ash works as expected when
aliases are configured in, and fails when not.

Example script using 'date' with different settings of TZ:

# TZ=Europe/London
# export TZ
# date
Thu May 30 17:18:49 BST 2002
# TZ=America/New_York date
Thu May 30 12:19:10 EDT 2002
# date
Thu May 30 17:19:12 BST 2002
# date TZ=America/New_York
Thu May 30 12:19:30 EDT 2002    <----- wrong, should be BST time (or error!)
# date
Thu May 30 17:19:35 BST 2002

Attached is a patch against revision 1.52 of ash.c which moves the checks so
that checkalias is updated regardless of whether CONFIG_ASH_ALIAS is set.
With this patch applied, the command shown above which should generate an
error does generate an error.

I have tested this patch with the 'dd' command too and that now works
correctly.

diff --git a/shell/ash.c b/shell/ash.c
index 366f704be8eec97fe74df94847d969f955f411e0..3d7043c8faca700776a0c669bb38033b477ae901 100644 (file)
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -9967,8 +9967,8 @@ static int
 readtoken() {
        int t;
 
-#ifdef CONFIG_ASH_ALIAS
        int savecheckalias = checkalias;
+#ifdef CONFIG_ASH_ALIAS
        int savecheckkwd = checkkwd;
        struct alias *ap;
 #endif
@@ -9983,9 +9983,7 @@ top:
 
        t = xxreadtoken();
 
-#ifdef CONFIG_ASH_ALIAS
        checkalias = savecheckalias;
-#endif
 
        if (checkkwd) {
                /*
@@ -10021,8 +10019,8 @@ top:
                }
        } else if (checkalias == 2 && isassignment(wordtext)) {
                lasttoken = t = TASSIGN;
-#ifdef CONFIG_ASH_ALIAS
        } else if (checkalias) {
+#ifdef CONFIG_ASH_ALIAS
                if (!quoteflag && (ap = *__lookupalias(wordtext)) != NULL && !(ap->flag & ALIASINUSE)) {
                        if (*ap->val) {
                                pushstring(ap->val, strlen(ap->val), ap);
@@ -10030,8 +10028,8 @@ top:
                        checkkwd = savecheckkwd;
                        goto top;
                }
-               checkalias = 0;
 #endif
+               checkalias = 0;
        }
 out:
 #ifdef DEBUG
@@ -12442,7 +12440,7 @@ findvar(struct var **vpp, const char *name)
 /*
  * Copyright (c) 1999 Herbert Xu <herbert@debian.org>
  * This file contains code for the times builtin.
- * $Id: ash.c,v 1.53 2002/07/03 23:19:22 andersen Exp $
+ * $Id: ash.c,v 1.54 2002/07/04 00:19:46 andersen Exp $
  */
 static int timescmd (int argc, char **argv)
 {