WAVE: Fix parse error in Associated Data List #309
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When reading an Associated Data List's sub-chunks JHOVE eats bytes according to the value of the `bytesLeft` variable which is initialized with the Associated Data List's size. Since the size encompasses not only the sub-chunks but also the Associated Data List's 4 bytes sized type ID field JHOVE should subtract 4 bytes from the `bytesLeft` variable before it starts reading sub-chunks.
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@@ Coverage Diff @@
## integration #309 +/- ##
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- Coverage 43.47% 43.47% -0.01%
Complexity 3308 3308
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Files 366 366
Lines 30122 30123 +1
Branches 5959 5959
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Hits 13096 13096
- Misses 14629 14630 +1
Partials 2397 2397
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Those strings are NULL terminated, calling trim() removes the NULL byte.
It also removes all trailing whitespace, which may not be desired.
Something like `str.replaceFirst("\0$", "")` would be more precise.
Anyway, trim() is used in this commit to be consistent with the rest of
the WAVE module where trim() is used as well.
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I added one tiny commit (11c9a0e) that treats NULL terminated strings like "foo\0" in the last line of the example above. |
david-russo
approved these changes
Feb 27, 2018
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In JHOVE 1.18.1, validating a WAVE file that contains an Associated Data List chunk results in the status "Not well-formed" with error message "Unexpected end of file".
Consider this minimal example (binary version is attached) which constitutes a WAVE file without any audio data (empty Data chunk) but with an Associated Data List:
The Associated Data List chunk (the chunk with ID "list") in this example has size 0x14 (little endian), meaning it holds 20 bytes of data. These 20 bytes include the list's type ID "adtl" and the nested sub-chunk (the chunk with ID "labl"): 4 bytes for the "adtl" string plus 16 bytes for the "labl" chunk.
When reading an Associated Data List's sub-chunks JHOVE eats bytes according to the value of the
bytesLeftvariable by calling thegetNextChunkHeader()method. ThebytesLeftvariable is initialized with the Associated Data List's size. So in this example JHOVE tries to read 20 bytes worth of sub-chunks. But alas, JHOVE ignores the fact that the "adtl" type ID has a size of its own! It should not read 20 bytes of sub-chunks, but only 16 bytes, allowing for the 4 bytes that are consumed by the type ID. So JHOVE should subtract 4 bytes from thebytesLeftvariable before it starts reading sub-chunks, just like it does in the ListInfoChunk class.This pull request adjusts this behaviour.
adtl.zip