From mboxrd@z Thu Jan  1 00:00:00 1970
From: Denys Vlasenko <vda.linux@googlemail.com>
Subject: dash bug: double-quoted "\" breaks glob protection for next char
Date: Tue, 13 Feb 2018 14:53:42 +0100
Message-ID: <CAK1hOcPW_MZ5Nq-0z-aMMMgzZbOZYXD_9kkxz1w+U-HY+E4gbw@mail.gmail.com>
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To: Herbert Xu <herbert@gondor.apana.org.au>, dash@vger.kernel.org

$ >'\zzzz'
$ >'\wwww'
$ dash -c 'echo "\*"'
\wwww \zzzz

The cause: uses "\\*" pattern instead of "\\\*".
The fix:

                        /* backslash */
                        case CBACK:
                                c = pgetc2();
                                if (c == PEOF) {
                                        USTPUTC(CTLESC, out);
                                        USTPUTC('\\', out);
                                        pungetc();
                                } else if (c == '\n') {
                                        nlprompt();
                                } else {
                                        if (
                                                dblquote &&
                                                c != '\\' && c != '`' &&
                                                c != '$' && (
                                                        c != '"' ||
                                                        eofmark != NULL
                                                )
                                        ) {
USTPUTC(CTLESC, out); // add this line
                                                USTPUTC('\\', out);
                                        }
                                        USTPUTC(CTLESC, out);
                                        USTPUTC(c, out);
                                        quotef++;
                                }