Summary: Buffer issues

[dr-jts]

Summary and categorization of issues with buffer algorithm.

Artifacts

• Buffer with Flat endcap produces artifacts #1028
• Buffer of closed LineString has "inverted hole" artifact #876
• Buffer has unexpected boundary artifacts #866
• Poor quality buffer curve for Flat endcap #739
• Buffer error - extra polygon fragments #650
• Negative buffer of a polygon can lie outside the input libgeos/geos#1208

Fixed Precision bugs

• Geometry.buffer with fixed precision removes hole #979
• Small buffer of a polygon returns an empty geometry #908

Buffer curve Quality

• Negative buffer operation leaves some collinear points (regression from 1.19.0) #1007
• Buffer with mitre join is incorrect due to short input segment #180