## #602 closed defect (fixed)

# [JTS works] GEOSOffsetCurve: IllegalArgumentException: RobustDeterminant encountered non-finite numbers

Reported by: | strk | Owned by: | |
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Priority: | major | Milestone: | 3.3.9 |

Component: | Default | Version: | 3.3.6 |

Severity: | Unassigned | Keywords: | |

Cc: |

### Description

Bug report origin: http://trac.osgeo.org/postgis/ticket/2099 Offending input (hexwkb): 010200000004000000B788150E6FB162407FABDE5E1D453AC00FB54CBB6EB162409E19426B1B453AC00FB54CBB6EB162409E19426B1B453AC033FBDBB16EB16240F24ABC1F1B453AC0 Operation: GEOSOffsetCurve(geom1_, 0, 0, GEOSBUF_JOIN_ROUND, 2);

### Change History (12)

### comment:1 Changed 8 years ago by

### comment:3 Changed 8 years ago by

Milestone: | 3.3.7 → 3.3.x |
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### comment:4 Changed 8 years ago by

NOTE: the same error occurs when passing a zero-length line to the function. Taking 5.6e-05 the same as zero may or may not be a solvable bug. I wonder if JTS survives this one.

### comment:5 Changed 8 years ago by

This works in JTS as near as I can tell. A zero-length line works as well.

### comment:6 Changed 8 years ago by

Summary: | GEOSOffsetCurve: IllegalArgumentException: RobustDeterminant encountered non-finite numbers → [JTS works] GEOSOffsetCurve: IllegalArgumentException: RobustDeterminant encountered non-finite numbers |
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MArtin: what does JTS return as an OffsetCurve? from a zero-length line ?

### comment:8 Changed 7 years ago by

The problem seems to originate in an attempt by OffsetegmentGenerator? to compute the offset of a zero or close-to-zero length segment, which results in a NaN ordinate offset. I guess it could be worked around this by omitting the zero or too-short segment from the list (I'm surprised this isn't done already by the simplification step).

### comment:9 Changed 7 years ago by

This is even worst, crashes the lib: ` LINESTRING(140 -26,149 -26.,149 -26.,149 -26) `

### comment:10 Changed 7 years ago by

To recap, this one throws an exception:

LINESTRING(0 1,0 2,0 2,0 0)

And this one aborts:

LINESTRING(0 1,0 2,0 2)

Pretty stable functionality ! :P

### comment:11 Changed 7 years ago by

Resolution: | → fixed |
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Status: | new → closed |

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For the record: the line has a computed length of 5.58135564343909e-05 units. Here's how the WKT looks like: