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********************* IBIS GOLDEN PARSER BUG REPORT FORM *********************
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INSTRUCTIONS

To report a bug in the IBIS golden parser.  Please fill out the top part
of the following form and send the complete form to ibischk-bug@vhdl.org.

A list of reported bugs will be maintained on vhdl.org.

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PARSER VERSION NUMBER: 
V2.1.15 

PLATFORM (SPARC, HP700, PC, etc.): 
PC

OS AND VERSION:
Linux 

REPORTED BY: Atul P. Agarwal, Apt Software Avenues Pvt Ltd

DATE: 6th February, 1998

DESCRIPTION OF BUG:
When the [Pullup] and [Pulldown] are both specified and one of them is 
empty and either a [Rising Waveform] or [Falling Waveform] is specified, 
the parser crashes in query.c. 

The point at which it crashes in the code was newly inserted to fix BUG21.
Essentially, the function qry_RngpIsBad is evaluated with the first argument 
NULL.

The Bug does not occur under Windows 95 because the model data structures
have been freed to release the memory and the call to qry_RngpIsBad is
never invoked.

Note that the pre conditions for the bug to occur are that both
[Pullup] and [Pulldown] must be specified and either one should be
empty and either a [Rising waveform] or [Falling waveform] must be
specified and must be non empty else BUG22 will hide this bug.
 
One solution is to insert a check on the first argument to qry_RngpIsBad
and return 1 if it is NULL. The other is to make sure that the conditions
under which qry_RngpIsBad is called are always "kosher". 

INSERT IBIS FILE DEMONSTRATING THE BUG:

[IBIS Ver]        2.1
[File Name]       empty.ibs
[File Rev]        0.1
|
|***************************************************************
|
[Component]      TEST
[Manufacturer]   Test File
[Package]
| variable      typ             min             max
R_pkg           0.0m            NA              NA
L_pkg           0.0nH           NA              NA
C_pkg           0.0pF           NA              NA
|
|***************************************************************
|
[Pin]           signal_name     model_name
1               One_Pin         OutputPin
|
[Model]     OutputPin
Model_type  Output
|                  typ   min   max
C_comp             0.0   NA    NA
[Voltage Range]    5.0   NA    NA

[Pullup]
| Voltage    I(typ)  I(min)  I(max)
5            1n       NA      NA
10           0n       NA      NA
[Pulldown]
| Voltage    I(typ)  I(min)  I(max)
[Rising Waveform]
0                0  NA NA
1n               5  NA NA
[End]


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******************** BELOW FOR ADMINISTRATION AND TRACKING *******************
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BUG NUMBER: 23

SEVERITY: [FATAL, SEVERE, MODERATE, ANNOYING, ENHANCEMENT]  SEVERE

PRIORITY: [HIGH, MEDIUM, LOW]                               MEDIUM

STATUS: [OPEN, CLOSED, WILL NOT FIX, NOT A BUG]             CLOSED

FIXED VERSION:  3.0.0,   2.1.17 

FIXED DATE:     3/98, 8/98

NOTES ON BUG FIX:  Bob Ross reports that it shows up in Version 2.1.11
                   Scheduled for ibischk2+ version2.1.16 and ibischk3

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