Hi,

I've tried to run SamToFastq on a sam file with unaligned reads. Right 
on the first line picardtools complains:

Exception in thread "main"
htsjdk.samtools.SAMFormatException: Error parsing text SAM
file. MAPQ must be zero if RNAME is not specified; Line 4
Line:
HWI-EA332_1_2_662_117/1 4       *       0       255     *       *       0       
0 
CCACACTACACCCTAACACACCCTAATCTAACCCTGGCCAACCTGTCTCTC 
BBBBCCCCBB@BCB?CBC@ABB?<>AB?CBCBB@BC>BB@BB7BCB<BCA?     RG:Z:007

After consulting the sam format specifications I think that this 
behavior is incorrect.
The read has bit 4 set in the FLAG field and with that "no assumption 
can be made about RNAME, POS, CIGAR, MAPQ", so picard shouldn't even 
look at MAPQ here.
Even if it did, I don't know whether it should expect MAPQ to be zero in 
the absence of RNAME as a MAPQ value of 255 "indicates that the mapping 
quality is not available", which seems to be about as reasonable as 
setting it to 0.

Please correct me if I'm getting this wrong,
Wolfgang


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