emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

hush: fix remaining known two bugs with IFS expansion. Closes 4027.

Browse Source 
function                                             old     new   delta
expand_vars_to_list                                 1054    1140     +86
parse_stream                                        2425    2479     +54
expand_on_ifs                                        258     310     +52
builtin_umask                                        133     132      -1
done_word                                            820     779     -41
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/2 up/down: 192/-42)           Total: 150 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2011-08-01 18:16:43 +02:00
parent 4fb53fb08c
commit 6e42b89b8d
3 changed files with 61 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
shell/hush.c
View File

@ -3265,14 +3265,6 @@ static int done_word(o_string *word, struct parse_context *ctx)
) {
p += 3;
}
if (p == word->data || p[0] != '\0') {
/* saw no "$@", or not only "$@" but some
* real text is there too */
/* insert "empty variable" reference, this makes
* e.g. "", $empty"" etc to not disappear */
o_addchr(word, SPECIAL_VAR_SYMBOL);
o_addchr(word, SPECIAL_VAR_SYMBOL);
}
}
command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
debug_print_strings("word appended to argv", command->argv);
@ -4516,6 +4508,13 @@ static struct pipe *parse_stream(char **pstring,
break;
case '\'':
dest.has_quoted_part = 1;
if (next == '\'' && !ctx.pending_redirect) {
insert_empty_quoted_str_marker:
nommu_addchr(&ctx.as_string, next);
i_getch(input); /* eat second ' */
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
o_addchr(&dest, SPECIAL_VAR_SYMBOL);
} else {
while (1) {
ch = i_getch(input);
if (ch == EOF) {
@ -4527,9 +4526,12 @@ static struct pipe *parse_stream(char **pstring,
break;
o_addqchr(&dest, ch);
}
}
break;
case '"':
dest.has_quoted_part = 1;
if (next == '"' && !ctx.pending_redirect)
goto insert_empty_quoted_str_marker;
if (dest.o_assignment == NOT_ASSIGNMENT)
dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
@ -4751,9 +4753,14 @@ static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len
/* Store given string, finalizing the word and starting new one whenever
* we encounter IFS char(s). This is used for expanding variable values.
* End-of-string does NOT finalize word: think about 'echo -$VAR-' */
static int expand_on_ifs(o_string *output, int n, const char *str)
* End-of-string does NOT finalize word: think about 'echo -$VAR-'.
* Return in *ended_with_ifs:
* 1 - ended with IFS char, else 0 (this includes case of empty str).
*/
static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
{
int last_is_ifs = 0;
while (1) {
int word_len;
@ -4774,27 +4781,36 @@ static int expand_on_ifs(o_string *output, int n, const char *str)
/*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
/*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
}
last_is_ifs = 0;
str += word_len;
if (!*str) /* EOL - do not finalize word */
break;
goto finalize; /* optimization (can just fall thru) */
}
/* Case "v=' a'; echo ''$v": we do need to finalize empty word */
/* We know str here points to at least one IFS char */
last_is_ifs = 1;
str += strspn(str, G.ifs); /* skip IFS chars */
if (!*str) /* EOL - do not finalize word */
break;
/* Start new word... but not always! */
/* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
if (output->has_quoted_part
/* Case "v=' a'; echo $v":
* here nothing precedes the space in $v expansion,
* therefore we should not finish the word
* (IOW: if there *is* word to finalize, only then do it)
* (IOW: if there *is* word to finalize, only then do it):
*/
|| (output->length && output->data[output->length - 1])
|| (n > 0 && output->data[output->length - 1])
) {
finalize:
o_addchr(output, '\0');
debug_print_list("expand_on_ifs", output, n);
n = o_save_ptr(output, n);
}
str += strspn(str, G.ifs); /* skip IFS chars */
}
if (ended_with_ifs)
*ended_with_ifs = last_is_ifs;
debug_print_list("expand_on_ifs[1]", output, n);
return n;
}
@ -5209,6 +5225,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
* expansion of right-hand side of assignment == 1-element expand.
*/
char cant_be_null = 0; /* only bit 0x80 matters */
int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
char *p;
debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
@ -5227,6 +5244,13 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
#if ENABLE_SH_MATH_SUPPORT
char arith_buf[sizeof(arith_t)*3 + 2];
#endif
if (ended_in_ifs) {
o_addchr(output, '\0');
n = o_save_ptr(output, n);
ended_in_ifs = 0;
}
o_addblock(output, arg, p - arg);
debug_print_list("expand_vars_to_list[1]", output, n);
arg = ++p;
@ -5255,7 +5279,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
while (G.global_argv[i]) {
n = expand_on_ifs(output, n, G.global_argv[i]);
n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
if (G.global_argv[i++][0] && G.global_argv[i]) {
/* this argv[] is not empty and not last:
@ -5332,7 +5356,7 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
!!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
if (val && val[0]) {
n = expand_on_ifs(output, n, val);
n = expand_on_ifs(&ended_in_ifs, output, n, val);
val = NULL;
}
} else { /* quoted $VAR, val will be appended below */
@ -5361,6 +5385,10 @@ static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
} /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
if (arg[0]) {
if (ended_in_ifs) {
o_addchr(output, '\0');
n = o_save_ptr(output, n);
}
debug_print_list("expand_vars_to_list[a]", output, n);
/* this part is literal, and it was already pre-quoted
* if needed (much earlier), do not use o_addQstr here! */

3
shell/hush_test/hush-parsing/starquoted2.right
View File

@ -1,4 +1,7 @@
Should be printed
Would not be printed by bash
Would not be printed by bash
Would not be printed by bash
Should be printed
Empty:
Empty:

6
shell/hush_test/hush-parsing/starquoted2.tests
View File

@ -8,9 +8,9 @@ for a in "$@"; do echo Should not be printed; done
# Yes, believe it or not, bash is mesmerized by "$@" and stops
# treating "" as "this word cannot be expanded to nothing,
# but must be at least null string". Now it can be expanded to nothing.
for a in "$@"""; do echo Should not be printed; done
for a in """$@"; do echo Should not be printed; done
for a in """$@"''"$@"''; do echo Should not be printed; done
for a in "$@"""; do echo Would not be printed by bash; done
for a in """$@"; do echo Would not be printed by bash; done
for a in """$@"''"$@"''; do echo Would not be printed by bash; done
for a in ""; do echo Should be printed; done
# Bug 207: "$@" expands to nothing, and we erroneously glob "%s\n" twice: