[geos-devel] [GEOS] #1010: Leak in GEOSLineMerge_r

[GEOS]

#1010: Leak in GEOSLineMerge_r
------------------------+--------------------------
 Reporter:  Algunenano  |      Owner:  geos-devel@…
     Type:  defect      |     Status:  new
 Priority:  major       |  Milestone:  3.9.0
Component:  Default     |    Version:  master
 Severity:  Unassigned  |   Keywords:
------------------------+--------------------------
 From Postgis tests with HEAD:
 {{{
 $ valgrind --leak-check=full --show-leak-kinds=all ./cunit/cu_tester
 test_geos_linemerge

 ==548693== 40 bytes in 1 blocks are indirectly lost in loss record 2 of 6
 ==548693==    at 0x4838DEF: operator new(unsigned long)
 (vg_replace_malloc.c:344)
 ==548693==    by 0x5C8C098:
 geos::operation::linemerge::EdgeString::getCoordinates()
 (EdgeString.cpp:66)
 ==548693==    by 0x5C8C1FD:
 geos::operation::linemerge::EdgeString::toLineString() (EdgeString.cpp:96)
 ==548693==    by 0x5C8D4CE:
 geos::operation::linemerge::LineMerger::merge() (LineMerger.cpp:130)
 ==548693==    by 0x5C8DADD:
 geos::operation::linemerge::LineMerger::getMergedLineStrings()
 (LineMerger.cpp:233)
 ==548693==    by 0x4BF67CA: operator() (geos_ts_c.cpp:1896)
 ==548693==    by 0x4BF67CA: execute<(lambda at geos_ts_c.cpp:1890:35),
 nullptr> (geos_ts_c.cpp:377)
 ==548693==    by 0x4BF67CA: GEOSLineMerge_r (geos_ts_c.cpp:1890)
 ==548693==    by 0x1AB257: lwgeom_linemerge (lwgeom_geos.c:727)
 ==548693==    by 0x125E18: test_geos_linemerge (cu_geos.c:89)
 ==548693==    by 0x4884117: ??? (in /usr/lib/libcunit.so.1.0.1)
 ==548693==    by 0x4884AAF: CU_run_test (in /usr/lib/libcunit.so.1.0.1)
 ==548693==    by 0x158A12: main (cu_tester.c:226)
 ==548693==
 ==548693== 96 bytes in 1 blocks are indirectly lost in loss record 3 of 6
 ==548693==    at 0x4838DEF: operator new(unsigned long)
 (vg_replace_malloc.c:344)
 ==548693==    by 0x5C184A1: allocate (new_allocator.h:114)
 ==548693==    by 0x5C184A1: allocate (alloc_traits.h:444)
 ==548693==    by 0x5C184A1: _M_allocate (stl_vector.h:343)
 ==548693==    by 0x5C184A1: _M_realloc_insert<const geos::geom::Coordinate
 &> (vector.tcc:440)
 ==548693==    by 0x5C184A1: push_back (stl_vector.h:1195)
 ==548693==    by 0x5C184A1:
 geos::geom::CoordinateArraySequence::add(geos::geom::Coordinate const&,
 bool) (CoordinateArraySequence.cpp:135)
 ==548693==    by 0x5C185F9:
 geos::geom::CoordinateArraySequence::add(geos::geom::CoordinateSequence
 const*, bool, bool) (CoordinateArraySequence.cpp:146)
 ==548693==    by 0x5C8C15D:
 geos::operation::linemerge::EdgeString::getCoordinates()
 (EdgeString.cpp:79)
 ==548693==    by 0x5C8C1FD:
 geos::operation::linemerge::EdgeString::toLineString() (EdgeString.cpp:96)
 ==548693==    by 0x5C8D4CE:
 geos::operation::linemerge::LineMerger::merge() (LineMerger.cpp:130)
 ==548693==    by 0x5C8DADD:
 geos::operation::linemerge::LineMerger::getMergedLineStrings()
 (LineMerger.cpp:233)
 ==548693==    by 0x4BF67CA: operator() (geos_ts_c.cpp:1896)
 ==548693==    by 0x4BF67CA: execute<(lambda at geos_ts_c.cpp:1890:35),
 nullptr> (geos_ts_c.cpp:377)
 ==548693==    by 0x4BF67CA: GEOSLineMerge_r (geos_ts_c.cpp:1890)
 ==548693==    by 0x1AB257: lwgeom_linemerge (lwgeom_geos.c:727)
 ==548693==    by 0x125E18: test_geos_linemerge (cu_geos.c:89)
 ==548693==    by 0x4884117: ??? (in /usr/lib/libcunit.so.1.0.1)
 ==548693==    by 0x4884AAF: CU_run_test (in /usr/lib/libcunit.so.1.0.1)
 }}}


 The bisection points to
 https://github.com/libgeos/geos/commit/7a7cbf84fc5d4369baaf4c6e0614f44d4207503f
 as the culprit.

 I've tried to readd the removed `delete` call but it doesn't fix it:
 - delete didn't fix it: https://github.com/Algunenano/geos/commit/f40a4eb8
 - unique_ptr didn't fix it:
 https://github.com/Algunenano/geos/commit/3e5f8c59
 - full revert does fix it:
 https://github.com/Algunenano/geos/commit/0e40b08a

 I'm not sure what is causing the leak in the changes, so I'm not opening a
 PR yet, but feel free to fix it if you see what the issue is.

-- 
Ticket URL: <https://trac.osgeo.org/geos/ticket/1010>
GEOS <http://trac.osgeo.org/geos>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).