FILTER line is malformed

[dridk]

Issue from jamescasbon#337

Background:
In FILTER, multiple filters should be separated by semicolons. The widely used, but not actively maintained, VarScan2 genomic variant caller uses commas instead. Moreover, VarScan2 does not add ##FILTER metadata for most of its filters. Picard FixVcfHeader can be used to fix missing FILTER metadata. A "fixed" metadata row will look like:
##FILTER=<ID="RefAvgRL,VarAvgRL",Description="Missing description: this FILTER line was added by Picard's FixVCFHeader">

Error:
PyVCF fails with:
`
Traceback (most recent call last):
File "/mnt/hdd/dnanexus/scripts_local/compare_vcfs.py", line 236, in
main()

File "/mnt/hdd/dnanexus/scripts_local/compare_vcfs.py", line 232, in main
run(parser.parse_args())

File "/mnt/hdd/dnanexus/scripts_local/compare_vcfs.py", line 166, in run
df_1 = vcf_to_dataframe(args.vcf_1)

File "/mnt/hdd/dnanexus/scripts_local/compare_vcfs.py", line 74, in vcf_to_dataframe
vcf_reader = vcf.Reader(open(vcf_file, "r"))

File "/home/myourshaw/.venv/dnanexus/lib/python3.10/site-packages/vcf/parser.py", line 300, in init
self._parse_metainfo()

File "/home/myourshaw/.venv/dnanexus/lib/python3.10/site-packages/vcf/parser.py", line 326, in _parse_metainfo
key, val = parser.read_filter(line)

File "/home/myourshaw/.venv/dnanexus/lib/python3.10/site-packages/vcf/parser.py", line 142, in read_filter
raise SyntaxError(

SyntaxError: One of the FILTER lines is malformed: ##FILTER=<ID="RefAvgRL,VarAvgRL",Description="Missing description: this FILTER line was added by Picard's FixVCFHeader">
`

Issue:
It might be more robust for PyVCF to treat a filter with commas as just one big filter name, as does Picard FixVcfHeader.
Instead of raising an exception, accept metadata with a filter ID inside double quotes and containing commas, e.g., ID="RefAvgRL,VarAvgRL".
Similarly, in the data, treat a FILTER value like RefAvgRL,VarAvgRL as a single entity. I think this solution is consistent with the VCF 4.2 spec for a filter name: String, no whitespace or semicolons permitted.

Possible pull request:
This hack (changing [^,] + to .+ worked to get me through an urgent analysis, but it may not be the best solution. At parser.py line 142
self.filter_pattern = re.compile(r'''##FILTER=< ID=(?P.+),\s* Description="(?P[^"]*)" >''', re.VERBOSE)

=======

I get the same problem, any update on this issue ?

I hoped switching to PyVCF3 (c.f. jamescasbon#335 ) would solve the issue but apparently not.

My bad, in my case the problem originated from a tag Source in a FILTER field:

##FILTER=<ID=xxx,Description="yyy",Source="zzz">

which is a INFO field tag according to https://samtools.github.io/hts-specs/ and not a FILTER field tag.

[dridk]

Could you five me a VCF example to test ?