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| author | Mike Frysinger <vapier@gentoo.org> | 2009-12-26 14:56:54 -0500 |
|---|---|---|
| committer | Karel Zak <kzak@redhat.com> | 2010-01-04 09:49:23 +0100 |
| commit | 45b1087e74075b815e66edf225e0b8bc46a855fb (patch) | |
| tree | e1f6790d05156b582b9261e3a6f360b04be99b7f | |
| parent | 387ade2a24cc6fd13e8b5db123c4fa47f430948d (diff) | |
| download | util-linux-old-45b1087e74075b815e66edf225e0b8bc46a855fb.tar.gz | |
pg: command enters infinite loop
In a multibyte locale such as en_GB.UTF-8, the pg command cannot handle files
containing a form feed character (ASCII 0x0c) at the start of a line. The
program enters an infinite loop.
I've traced the problem to the function endline_for_mb in file pg.c. The code
assumes that the libc function wcwidth will return a nonnegative value, which
is not true for a form feed character. wcwidth returns -1 and the unsigned
variable "pos" goes into underflow.
I'll attach a patch which tests whether the character is printable before
calling wcwidth. If not, it uses instead the width of the constant L'?' which
is later used to replace nonprintable characters. I trust that we can assume
printability of this constant :-)
Steps to Reproduce:
1. Select a multibyte locale (tested with en_GB.UTF-8)
2. Create a file with a form feed character (0x0c) at the start of a line.
3. Try to display this file using the pg command.
Reported-by: Mark Calderbank <m.calderbank@iname.com>
Reported-by: Mike Frysinger <vapier@gentoo.org>
Addresses: https://bugs.gentoo.org/297717
Signed-off-by: Karel Zak <kzak@redhat.com>
| -rw-r--r-- | text-utils/pg.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/text-utils/pg.c b/text-utils/pg.c index b2c4d873..24c12217 100644 --- a/text-utils/pg.c +++ b/text-utils/pg.c @@ -448,7 +448,10 @@ endline_for_mb(unsigned col, char *s) pos += TABSIZE - (pos % TABSIZE); break; default: - pos += wcwidth(*p); + if (iswprint(*p)) + pos += wcwidth(*p); + else + pos += wcwidth(L'?'); } if (pos > col) { if (*p == L'\t') |