[DAFFODIL-2688] prefixed length field when not enough bits available gives Runtime SDE not parse error

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.0
• Fix Version/s: 3.7.0
• Component/s: Back End
• Assignee: Mike Beckerle
• Reporter: Mike Beckerle
• Created: 08/Apr/22 03:10
• Updated: 29/Mar/24 16:33
• Resolved: 29/Mar/24 14:52

Description

When a prefixed length, let's say a 4-byte unsigned int, is being parsed, and there are not 32-bits available (because, for example you are at end of data), then you don't get a parse error. Instead you get:

Runtime Schema Definition Error: Prefixed length result must be non-negative after dfdl:prefixIncludesPrefixLength adjustment , but was: -4 

This needs to be a parse error due to the insufficient bits. 

If you trace, you get this:

parser: <BinaryIntegerKnownLengthParser/>
bitPosition: 1920
data:
            │                                        │
  87654321  0011 2233 4455 6677 8899 aabb ccdd eeff  0123456789abcdef
infoset:
  <?xml version="1.0" encoding="UTF-8"?>
  <message (prefixLength)></message (prefixLength)>
diff:
  (no differences)
failure:
  Parse Error: Insufficient bits in data. Needed 32 bit(s) but found only 0 available.
  Schema context: message (prefixLength) Location line 385 in file:/....../common.dfdl.xsd
  Data location was preceding byte 240 limit(bytes) 240
----------------------------------------------------------------- 347org.apache.daffodil.tdml.TDMLExceptionImpl: (Implementation: daffodil) Runtime Schema Definition Error: Prefixed length result must be non-negative after dfdl:prefixIncludesPrefixLength adjustment , but was: -4 

So you can see how it's just out of data, yet getting an RSDE on this.