Whole file

geographiclib/geographiclib-python

The author described this change as “Add planimeter reverse arctic test to catch transit bug and fix.”. It counts as a record because the check below fails on the code as it stood at 1db690db5 and passes on d25401a86, with nothing else changed between the two runs.

Projectgeographiclib/geographiclib-python

Fix saved2022-03-08

Sharing licenceMIT · LICENSE

Change size+6 −8

What the code was meant to do, written into the code itself as a save note

Add planimeter reverse arctic test to catch transit bug and fix.

The change

61	61		lon12, _ = Math.AngDiff(lon1, lon2)
62	62		lon1 = Math.AngNormalize(lon1)
63	63		lon2 = Math.AngNormalize(lon2)
64		-	cross = (1 if lon1 <= 0 < lon2 and lon12 > 0
65		-	else (-1 if lon2 <= 0 < lon1 and lon12 < 0 else 0))
66		-	return cross
	64	+	return (1 if lon12 > 0 and ( lon1 < 0 <= lon2 or
	65	+	(lon1 > 0 and lon2 == 0))
	66	+	else (-1 if lon12 < 0 and lon2 < 0 <= lon1 else 0))
67	67
68	68		@staticmethod
69	69		def _transitdirect(lon1, lon2):
70	70		"""Count crossings of prime meridian for AddEdge."""
71	71		# We want to compute exactly
72		-	# int(ceil(lon2 / 360)) - int(ceil(lon1 / 360))
73		-	# Since we only need the parity of the result we can use std::remquo but
74		-	# this is buggy with g++ 4.8.3 and requires C++11. So instead we do
	72	+	# int(floor(lon2 / 360)) - int(floor(lon1 / 360))
75	73		lon1 = math.fmod(lon1, 720.0); lon2 = math.fmod(lon2, 720.0)
76		-	return ( (1 if (-360 < lon2 <= 0 or lon2 > 360) else 0) -
77		-	(1 if (-360 < lon1 <= 0 or lon1 > 360) else 0) )
	74	+	return ( (0 if (0 <= lon2 < 360 or lon2 < -360) else 1) -
	75	+	(0 if (0 <= lon1 < 360 or lon1 < -360) else 1 ) )
78	76
79	77		@staticmethod
80	78		def _areareduceA(area, area0, crossings, reverse, sign):

The check that tells the two apart

fail→pass·geographiclib/test/test_geodesic.py::PlanimeterTest::test_Planimeter12r

Check file geographiclib/test/test_geodesic.py, taken without changes from the fix and copied onto the older code, so the exact same check runs against both versions.

Origin and history

The fixd25401a860ad4ac8fc0044b591f7cabadafad71d

The code before it1db690db53ccaebb5c8bbc6c927d0a63ecf0df13

Broken version dated2022-03-06

Modulegeographiclib.polygonarea

Units changedPolygonArea

Fingerprint6d5f4d5ddb011dd4

Checked2026-08-18 by goldset/0.1

Every field above is generated by our program. None of it is written by hand.

What the code was meant to do, written into the code itself as a save note

The change

The check that tells the two apart

Origin and history

Other bugs found in geographiclib/geographiclib-python