From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6845 invoked by alias); 9 Dec 2015 16:24:45 -0000 Mailing-List: contact zsh-workers-help@zsh.org; run by ezmlm Precedence: bulk X-No-Archive: yes List-Id: Zsh Workers List List-Post: List-Help: X-Seq: 37364 Received: (qmail 8562 invoked from network); 9 Dec 2015 16:24:44 -0000 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on f.primenet.com.au X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.0 X-AuditID: cbfec7f4-f79026d00000418a-65-566855c8cbd2 Date: Wed, 09 Dec 2015 16:24:28 +0000 From: Peter Stephenson To: zsh-workers@zsh.org Subject: Re: Bug: [ "(" = ")" ] is true Message-id: <20151209162428.1ad53b89@pwslap01u.europe.root.pri> In-reply-to: <56684A0A.8010404@inlv.org> References: <56684A0A.8010404@inlv.org> Organization: Samsung Cambridge Solution Centre X-Mailer: Claws Mail 3.7.9 (GTK+ 2.22.0; i386-redhat-linux-gnu) MIME-version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrHLMWRmVeSWpSXmKPExsVy+t/xq7onQjPCDA5PsrA42PyQyYHRY9XB D0wBjFFcNimpOZllqUX6dglcGY/3KhZ8UKhYsOIHcwPjFYkuRk4OCQETiZ/v17FD2GISF+6t ZwOxhQSWMkq0vg7tYuQCsmcwSTw7+I8JwjnNKNHU+pcZwjnDKPHl/S5mkBYWAVWJOw8WgI1i EzCUmLppNiOILSIgLnF27XkWEFtYQF1i54OjYCt4Bewlbq3tAarn4OAU0JC49tsXYrO6xNGl P1hBbH4BfYmrfz8xQVxnLzHzyhlGiFZBiR+T74GNZBbQkti8rYkVwpaX2LzmLTPMnBt3d7NP YBSehaRlFpKWWUhaFjAyr2IUTS1NLihOSs811CtOzC0uzUvXS87P3cQICeUvOxgXH7M6xCjA wajEw3vBJT1MiDWxrLgy9xCjBAezkghvjW9GmBBvSmJlVWpRfnxRaU5q8SFGaQ4WJXHeubve hwgJpCeWpGanphakFsFkmTg4pRoYo/l4o83e3jmyoufDfsaXaTLNmsHL59vJ5TZ0OW7apKkm xbpmH6OuVqL+XxOljqOVJXWS/0OLtBSOTni4Sd3vwZ1vrhal+xbM1Z9W4vYm7ULXBdu4ibrN fc1OXxrnNh74tHeRY+DpuwWTRJeZNEyJcO2c65l35GnWMx62Q4ZyM25zP5SR7f2gxFKckWio xVxUnAgAD+wIgWECAAA= On Wed, 9 Dec 2015 16:34:34 +0100 Martijn Dekker wrote: > There is a string comparison bug with `[' and `test'; the result is true > if the first string starts with '(' and the second string starts with ')'. > > $ [ "(" = ")" ] && echo oops || echo ok > oops This is yet another result of a folorn attempt to handle extensions of the "[" syntax consistently. We can't tell if "(" ... ")" are for group or are arguments to a command, so we guess. However, as groups are an extension of the most basic syntax, we should first try the latter. Note that [ "(" string ")" ] and [ "(" "" ")" ] are valid tests that return true and false respectively. (They tend to suggest that whoever wrote those tests has lost the plot, but, well.) > $ [ "((" = "))" ] && echo oops || echo ok > oops This seems to be a more obvious bug that we only care about the first character. I can't see how that could ever possibly be right. It's possible there may have been some confusion over the fact that if we were parsing this properly for "[[" then the "(" and ")" wouldn't need to be in separate words, but that doesn't apply to "test" / "[". Added some "const"s in text.c with a little trepidation --- but I think it's a long time since we had problems with older OSes in that department. diff --git a/Src/builtin.c b/Src/builtin.c index cac4f42..b06bc6d 100644 --- a/Src/builtin.c +++ b/Src/builtin.c @@ -6463,7 +6463,13 @@ bin_test(char *name, char **argv, UNUSED(Options ops), int func) nargs = arrlen(argv); if (nargs == 3 || nargs == 4) { - if (*argv[0] == '(' && *argv[nargs-1] == ')') { + /* + * As parentheses are an extension, we need to be careful --- + * if this is a three-argument expression that could + * be a binary operator, prefer that. + */ + if (!strcmp(argv[0], "(") && !strcmp(argv[nargs-1],")") && + (nargs != 3 || !is_cond_binary_op(argv[1]))) { argv[nargs-1] = NULL; argv++; } diff --git a/Src/text.c b/Src/text.c index 9421d70..04acd2a 100644 --- a/Src/text.c +++ b/Src/text.c @@ -40,9 +40,32 @@ /**/ int text_expand_tabs; +/* + * Binary operators in conditions. + * There order is tied to the order of the definitions COND_STREQ + * et seq. in zsh.h. + */ +static const char *cond_binary_ops[] = { + "=", "!=", "<", ">", "-nt", "-ot", "-ef", "-eq", + "-ne", "-lt", "-gt", "-le", "-ge", "=~" +}; + static char *tptr, *tbuf, *tlim, *tpending; static int tsiz, tindent, tnewlins, tjob; +/**/ +int +is_cond_binary_op(const char *str) +{ + const char **op; + for (op = cond_binary_ops; *op; op++) + { + if (!strcmp(str, *op)) + return 1; + } + return 0; +} + static void dec_tindent(void) { @@ -120,7 +143,7 @@ taddchr(int c) /**/ static void -taddstr(char *s) +taddstr(const char *s) { int sl = strlen(s); char c; @@ -822,11 +845,6 @@ gettext2(Estate state) break; case WC_COND: { - static char *c1[] = { - "=", "!=", "<", ">", "-nt", "-ot", "-ef", "-eq", - "-ne", "-lt", "-gt", "-le", "-ge", "=~" - }; - int ctype; if (!s) { @@ -912,7 +930,7 @@ gettext2(Estate state) /* Binary test: `a = b' etc. */ taddstr(ecgetstr(state, EC_NODUP, NULL)); taddstr(" "); - taddstr(c1[ctype - COND_STREQ]); + taddstr(cond_binary_ops[ctype - COND_STREQ]); taddstr(" "); taddstr(ecgetstr(state, EC_NODUP, NULL)); if (ctype == COND_STREQ || diff --git a/Test/C02cond.ztst b/Test/C02cond.ztst index 40bbf42..9e13696 100644 --- a/Test/C02cond.ztst +++ b/Test/C02cond.ztst @@ -389,6 +389,18 @@ F:Failures in these cases do not indicate a problem in the shell. >Not zero 5 >Not zero 6 + [ '(' = ')' ] || print OK 1 + [ '((' = '))' ] || print OK 2 + [ '(' = '(' ] && print OK 3 + [ '(' non-empty-string ')' ] && echo OK 4 + [ '(' '' ')' ] || echo OK 5 +0:yet more old-fashioned test fix ups: prefer comparison to parentheses +>OK 1 +>OK 2 +>OK 3 +>OK 4 +>OK 5 + %clean # This works around a bug in rm -f in some versions of Cygwin chmod 644 unmodish