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From: Florian Weimer <fweimer@redhat.com>
To: libc-alpha@sourceware.org
Subject: [PATCH 2/5] locale: Fix signed char bug in lr_getc
Date: Thu, 19 May 2022 23:06:34 +0200	[thread overview]
Message-ID: <619cade7e73dc33184bf4247b739d54cd9d7d8b3.1652994079.git.fweimer@redhat.com> (raw)
In-Reply-To: <cover.1652994079.git.fweimer@redhat.com>

The array lr->buf contains characters, which can be signed.  A 0xff
byte in the input could be incorrectly reported as EOF.  More
importantly, get_string in linereader.c converts a signed input byte
to a Unicode code point using ADDWC ((uint32_t) ch), under the
assumption that this decodes the ISO-8859-1 input encoding.  If char
is signed, this does not give the correct result.  This means that
ISO-8859-1 input files for localedef are not actually supported,
contrary to the comment in get_string.  This is a happy accident because
we can therefore change the file encoding to UTF-8 without impacting
backwards compatibility.

While at it, remove the \32 check for MS-DOS end-of-file character (^Z).
---
 locale/programs/linereader.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/locale/programs/linereader.h b/locale/programs/linereader.h
index 0fb10ec833..653a71d2d1 100644
--- a/locale/programs/linereader.h
+++ b/locale/programs/linereader.h
@@ -134,7 +134,7 @@ lr_getc (struct linereader *lr)
 	return EOF;
     }
 
-  return lr->buf[lr->idx] == '\32' ? EOF : lr->buf[lr->idx++];
+  return lr->buf[lr->idx++] & 0xff;
 }
 
 
-- 
2.35.3



  parent reply	other threads:[~2022-05-19 21:06 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-19 21:06 [PATCH 0/5] Assume UTF-8 encoding for localedef input files Florian Weimer
2022-05-19 21:06 ` [PATCH 1/5] locale: Turn ADDC and ADDS into functions in linereader.c Florian Weimer
2022-07-04 19:54   ` Carlos O'Donell
2022-05-19 21:06 ` Florian Weimer [this message]
2022-07-04 19:54   ` [PATCH 2/5] locale: Fix signed char bug in lr_getc Carlos O'Donell
2022-05-19 21:06 ` [PATCH 3/5] locale: Introduce translate_unicode_codepoint into linereader.c Florian Weimer
2022-07-04 19:54   ` Carlos O'Donell
2022-05-19 21:06 ` [PATCH 4/5] locale: localdef input files are now encoded in UTF-8 Florian Weimer
2022-07-04 19:54   ` Carlos O'Donell
2022-05-19 21:06 ` [PATCH 5/5] de_DE: Convert to UTF-8 Florian Weimer
2022-07-04 19:54   ` Carlos O'Donell
2022-07-05  9:27   ` Andreas Schwab
2022-07-05  9:55     ` Florian Weimer
2022-07-05 10:38       ` Andreas Schwab
2022-07-04 19:54 ` [PATCH 0/5] Assume UTF-8 encoding for localedef input files Carlos O'Donell

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