#3558: A bug in a debugging output of handler.c
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Reporter: hhorak | Owner: mutt-dev
Type: defect | Status: new
Priority: minor | Milestone:
Component: mutt | Version: 1.5.21
Keywords: |
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This issue has been originally reported by Michal Jaegermann:
https://bugzilla.redhat.com/770892
With debugging code turned on mutt may get sometimes bogus messages when
saving base64 encoded attachments. Like that:
handler.c:310 [mutt_decode_base64()]: didn't get a multiple of 4 chars.
This is from this code:
{{{
while (len > 0)
{
for (i = 0 ; i < 4 && len > 0 ; len--)
{
if ((ch = fgetc (s->fpin)) == EOF)
break;
if (ch >= 0 && ch < 128 && (base64val(ch) != -1 || ch == '='))
buf[i++] = ch;
}
if (i != 4)
{
dprint (2, (debugfile, "%s:%d [mutt_decode_base64()]: "
"didn't get a multiple of 4 chars.\n", __FILE__,
__LINE__));
break;
}
......
}
}}}
and a message may be bogus because it will happen also when i is 0 - which
is definitely a multiple of 4 and means that we just finished decoding.
That does happen in "real life" but it is easy to construct simple demo
example.
Just put into an attachment results of 'echo -n abc | base64', which comes
to YWJj, followed by a new line. Then the second run of 'while' loop
starts with len set to 1, nothing is put in buf so i ends as 0 and 4*0 is
deemed not to be a multiple of 4. :-)
To fix simply add 'i == 0 && break;' before "dprint" line.
--
Ticket URL: <http://dev.mutt.org/trac/ticket/3558>
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