From afdcd12ed71abdeab16961a0308c84f7147b66b2 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sat, 5 Jul 2008 17:40:04 +0000 Subject: hush: fix a case where "$@" must expand to no word at all --- shell/hush.c | 26 ++++++++++++++++++++------ 1 file changed, 20 insertions(+), 6 deletions(-) (limited to 'shell/hush.c') diff --git a/shell/hush.c b/shell/hush.c index 5b5a54241..2c1d31c6d 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -2380,7 +2380,10 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) p = strchr(p, SPECIAL_VAR_SYMBOL); first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */ - ored_ch |= first_ch; + /* "$@" is special. Even if quoted, it can still + * expand to nothing (not even an empty string) */ + if ((first_ch & 0x7f) != '@') + ored_ch |= first_ch; val = NULL; switch (first_ch & 0x7f) { /* Highest bit in first_ch indicates that var is double-quoted */ @@ -2401,6 +2404,7 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) i = 1; if (!global_argv[i]) break; + ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */ if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ smallint sv = output->o_quote; /* unquoted var's contents should be globbed, so don't quote */ @@ -2932,15 +2936,25 @@ static int done_word(o_string *word, struct p_context *ctx) } } #endif - if (word->nonnull /* we saw "xx" or 'xx' */ + if (word->nonnull /* word had "xx" or 'xx' at least as part of it */ /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */ && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL) /* (otherwise it's "abc".... and is already safe) */ ) { - /* Insert "empty variable" reference, this makes - * e.g. "", $empty"" etc to not disappear */ - o_addchr(word, SPECIAL_VAR_SYMBOL); - o_addchr(word, SPECIAL_VAR_SYMBOL); + /* but exclude "$@"! it expands to no word despite "" */ + char *p = word->data; + while (p[0] == SPECIAL_VAR_SYMBOL + && (p[1] & 0x7f) == '@' + && p[2] == SPECIAL_VAR_SYMBOL + ) { + p += 3; + } + if (p == word->data || p[0] != '\0') { + /* Insert "empty variable" reference, this makes + * e.g. "", $empty"" etc to not disappear */ + o_addchr(word, SPECIAL_VAR_SYMBOL); + o_addchr(word, SPECIAL_VAR_SYMBOL); + } } child->argv = add_malloced_string_to_strings(child->argv, xstrdup(word->data)); debug_print_strings("word appended to argv", child->argv); -- cgit v1.2.3