[asterisk-bugs] [Asterisk 0014812]: ast_read() used with incorrect ast_waitfor() in app_fax.c

[Asterisk Bug Tracker]

A NOTE has been added to this issue. 
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http://bugs.digium.com/view.php?id=14812 
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Reported By:                caspy
Assigned To:                
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Project:                    Asterisk
Issue ID:                   14812
Category:                   Applications/app_fax
Reproducibility:            always
Severity:                   minor
Priority:                   normal
Status:                     feedback
Asterisk Version:           1.6.0.7 
Regression:                 No 
SVN Branch (only for SVN checkouts, not tarball releases): N/A 
SVN Revision (number only!):  
Request Review:              
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Date Submitted:             2009-04-02 11:36 CDT
Last Modified:              2009-04-03 09:04 CDT
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Summary:                    ast_read() used with incorrect ast_waitfor() in
app_fax.c
Description: 
in 1.6.0.7 in main/channel.c some changes are made to check for correct
usage of ast_waitfor() before each ast_read().

in my case, as soon as i start ReceiveFAX() application from dialplan,
messages like this begin to flood log:
ERROR[14159] channel.c: ast_read() called with no recorded file
descriptor.


looking into transmit_audio() (and transmit_t38() too) of apps/app_fax.c
we can see this:
===
        while (!s->finished) {
                res = ast_waitfor(s->chan, 20);
                if (res < 0)
                        break;
                else if (res > 0)
                        res = 0;

                inf = ast_read(s->chan);
===

if i understand correctly, ast_waitfor() returns zero, when the is nothing
to read. but in provided code we can see that reading is still beeing
done.

am i right?
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Relationships       ID      Summary
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related to          0014769 [patch] Improvements/fixes for app_fax
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---------------------------------------------------------------------- 
 (0102666) caspy (reporter) - 2009-04-03 09:04
 http://bugs.digium.com/view.php?id=14812#c102666 
---------------------------------------------------------------------- 
done.
patch from 0014769 resolves this issue. 

Issue History 
Date Modified    Username       Field                    Change               
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2009-04-03 09:04 caspy          Note Added: 0102666                          
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