public inbox for gcc-prs@sourceware.org help / color / mirror / Atom feed
From: peturr02@ru.is To: gcc-gnats@gcc.gnu.org Subject: libstdc++/9520: Garbled input from wcin Date: Fri, 31 Jan 2003 12:16:00 -0000 [thread overview] Message-ID: <20030131121333.14762.qmail@sources.redhat.com> (raw) >Number: 9520 >Category: libstdc++ >Synopsis: Garbled input from wcin >Confidential: no >Severity: serious >Priority: medium >Responsible: unassigned >State: open >Class: sw-bug >Submitter-Id: net >Arrival-Date: Fri Jan 31 12:16:01 UTC 2003 >Closed-Date: >Last-Modified: >Originator: peturr02@ru.is >Release: gcc-3.2.1 >Organization: >Environment: Red Hat Linux 8.0 >Description: If wcin.rdbuf()->sgetc() is called followed by wcin.rdbuf()->sbumpc(), the return value is not always the same, unless the charset in use happens to be ISO-8859-1. Reason: basic_filebuf<wchar_t>::_M_underflow_common returns wide characters to the FILE* using ungetc. This happens to work if the charset is ISO-8859-1 (because the values are the same as in UCS-4), but breaks for all other single-byte charsets. Note that there is an even more serious bug here when dealing with multibyte charsets: in general a single wide character can have been converted from more than one narrow character. This is however shadowed by other problems in _M_underflow_common. >How-To-Repeat: See attachment. >Fix: >Release-Note: >Audit-Trail: >Unformatted: ----gnatsweb-attachment---- Content-Type: text/plain; name="ungetcbug.cc" Content-Disposition: inline; filename="ungetcbug.cc" #include <iostream> #include <fstream> #include <locale> #include <cwchar> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> int main() { using namespace std; const char* name = "tmp"; filebuf fbuf1; fbuf1.open(name, ios_base::out | ios_base::trunc); for (int i = 1; i < 256; ++i) fbuf1.sputc(static_cast<unsigned char>(i)); fbuf1.close(); int fd = open(name, O_RDONLY); assert(fd != -1); dup2(fd, 0); locale loc ("en_US.ISO-8859-15"); locale::global(loc); wcin.imbue(loc); for (int j = 1; j < 256; ++j) { wint_t c1 = wcin.rdbuf()->sgetc(); wint_t c2 = wcin.rdbuf()->sbumpc(); assert(c1 == c2); assert(c1 != WEOF); } return 0; }
next reply other threads:[~2003-01-31 12:16 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2003-01-31 12:16 peturr02 [this message] 2003-05-16 19:59 bkoz
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20030131121333.14762.qmail@sources.redhat.com \ --to=peturr02@ru.is \ --cc=gcc-gnats@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).