ash: [EXPAND] Split unquoted $@/$* correctly when IFS is set but empty

Upstream commit:

    Date: Wed, 8 Oct 2014 15:24:23 +0800
    [EXPAND] Split unquoted $@/$* correctly when IFS is set but empty

    Currently we do not field-split $@/$* when it isn't quoted and IFS
    is set but empty.  This is obviously wrong.  This patch fixes this.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/shell/ash.c b/shell/ash.c
index e4349ccad..56dbcb7d1 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -6606,7 +6606,7 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
  * ash -c 'echo ${#1#}'  name:'1=#'
  */
 static NOINLINE ssize_t
-varvalue(char *name, int varflags, int flags, struct strlist *var_str_list)
+varvalue(char *name, int varflags, int flags, struct strlist *var_str_list, int *nulonly)
 {
         const char *p;
         int num;
@@ -6619,7 +6619,8 @@ varvalue(char *name, int varflags, int flags, struct strlist *var_str_list)
         int quotes = (discard ? 0 : (flags & QUOTES_ESC)) | QUOTES_KEEPNUL;
         int syntax = quoted ? DQSYNTAX : BASESYNTAX;
 
-        sep = quoted ? ((flags & EXP_FULL) << CHAR_BIT) : 0;
+        sep = *nulonly ? (flags & EXP_FULL) << CHAR_BIT : 0;
+        *nulonly = 0;
 
         switch (*name) {
         case '$':
@@ -6664,10 +6665,11 @@ varvalue(char *name, int varflags, int flags, struct strlist *var_str_list)
                 }
                 /* fall through */
         case '*':
-                sep = ifsset() ? (unsigned char)(ifsval()[0]) : ' ';
+                sep |= ifsset() ? (unsigned char)(ifsval()[0]) : ' ';
  param:
                 ap = shellparam.p;
                 sepc = sep;
+                *nulonly = !sepc;
                 if (!ap)
                         return -1;
                 while ((p = *ap++) != NULL) {
@@ -6757,6 +6759,7 @@ evalvar(char *p, int flags, struct strlist *var_str_list)
         char subtype;
         int quoted;
         char easy;
+        int nulonly;
         char *var;
         int patloc;
         int startloc;
@@ -6767,11 +6770,12 @@ evalvar(char *p, int flags, struct strlist *var_str_list)
         quoted = flags & EXP_QUOTED;
         var = p;
         easy = (!quoted || (*var == '@' && shellparam.nparam));
+        nulonly = easy;
         startloc = expdest - (char *)stackblock();
         p = strchr(p, '=') + 1; //TODO: use var_end(p)?
 
  again:
-        varlen = varvalue(var, varflags, flags, var_str_list);
+        varlen = varvalue(var, varflags, flags, var_str_list, &nulonly);
         if (varflags & VSNUL)
                 varlen--;
 
@@ -6865,7 +6869,7 @@ evalvar(char *p, int flags, struct strlist *var_str_list)
                 /* Remove any recorded regions beyond start of variable */
                 removerecordregions(startloc);
  record:
-                recordregion(startloc, expdest - (char *)stackblock(), quoted);
+                recordregion(startloc, expdest - (char *)stackblock(), nulonly);
         }
 
  end: