Вот еще нашел трабл:
Тестовый набор брался вот из такого bbox:
<bounds minlat='56.7182618' minlon='61.3124124' maxlat='56.7834254' maxlon='61.4764193'/>
Было:
; WayID = 38608343
; place = town
[POLYGON]
Type=0x2
EndLevel=3
DontFind=Y
Data1=(56.77969,61.31915),(56.78045,61.31742),(56.78246,61.31949),(56.78286,61.31658),(56.78258,61.31420),(56.78096,61.31262),(56.78120,61.31241),(56.78343,61.31241),(56.78343,61.32243)
Data1=(56.78300,61.35362),(56.78343,61.35067),(56.78343,61.35414)
[END]
...
; WayID = 113836699
; natural = wood
[POLYGON]
Type=0x50
EndLevel=3
Data0=(56.76600,61.31853),(56.76502,61.32032),(56.76503,61.32224),(56.76439,61.32171),(56.76470,61.31910),(56.76371,61.31998),(56.76334,61.31853),(56.76262,61.31955),(56.76233,61.31962),(56.76224,61.32016),(56.76177,61.32062),(56.76175,61.32096),(56.76139,61.32104),(56.76075,61.32101),(56.76050,61.32045),(56.75991,61.32091),(56.75897,61.32083),(56.75844,61.32068),(56.75834,61.32038),(56.75813,61.32013),(56.75699,61.31712),(56.75704,61.31646),(56.75746,61.31590),(56.75717,61.31564),(56.75799,61.31268),(56.75836,61.31256),(56.75839,61.31241),(56.76457,61.31241),(56.76433,61.31267),(56.76454,61.31309),(56.76429,61.31348),(56.76413,61.31474),(56.76508,61.31660),(56.76601,61.31554),(56.76640,61.31628),(56.76641,61.31801),(56.76621,61.31839),(56.76659,61.31912)
Data0=(56.76505,61.31249),(56.76500,61.31241),(56.76514,61.31241)
[END]
Стало
; WayID = 38608343
; place = town
[POLYGON]
Type=0x2
Label=Заречный
EndLevel=3
DontFind=Y
Data1=(56.77969,61.31915),(56.78045,61.31742),(56.78246,61.31949),(56.78286,61.31658),(56.78258,61.31420),(56.78096,61.31262),(56.78120,61.31241),(56.78343,61.31241),(56.78343,61.32243)
[END]
...
; WayID = 113836699
; natural = wood
[POLYGON]
Type=0x50
EndLevel=3
Data0=(56.76600,61.31853),(56.76502,61.32032),(56.76503,61.32224),(56.76439,61.32171),(56.76470,61.31910),(56.76371,61.31998),(56.76334,61.31853),(56.76262,61.31955),(56.76233,61.31962),(56.76224,61.32016),(56.76177,61.32062),(56.76175,61.32096),(56.76139,61.32104),(56.76075,61.32101),(56.76050,61.32045),(56.75991,61.32091),(56.75897,61.32083),(56.75844,61.32068),(56.75834,61.32038),(56.75813,61.32013),(56.75699,61.31712),(56.75704,61.31646),(56.75746,61.31590),(56.75717,61.31564),(56.75799,61.31268),(56.75836,61.31256),(56.75839,61.31241),(56.76457,61.31241),(56.76433,61.31267),(56.76454,61.31309),(56.76429,61.31348),(56.76413,61.31474),(56.76508,61.31660),(56.76601,61.31554),(56.76640,61.31628),(56.76641,61.31801),(56.76621,61.31839),(56.76659,61.31912)
[END]
Т.е. от полигонов, попадающих в область обрезки по несколько раз, остается только один.