[echoix]

Description

Vect_read_area_to_wkb(), Vect_read_line_to_wkb() and Vect_line_to_wkb() returned the buffer allocated by GEOS. It has to be released with GEOSFree(), but the Python code in pygrass released it with G_free(). That works when all libraries share one C runtime, as on Linux. When GEOS and GRASS use different runtimes, as on Windows, it corrupts the heap. On Windows, test_pygrass_vector_doctests.py stops without a traceback after seven tests, in areas_to_wkb_list(), and has been failing on main.

The WKT functions in the same file already copy the GEOS result into memory from G_store() and free the original, so this makes the WKB functions consistent with them.

• Copy the buffer into memory from G_malloc() and release the GEOS one with GEOSFree(). G_free() is then correct for the caller. The return value is documented as such. No C code calls these functions.
• Line.to_wkb() and Area.to_wkb() in pygrass never freed the buffer. Free it after copying the bytes.

Motivation and context

Heap corruption on Windows, and a memory leak on all platforms.

How has this been tested?

New pytest tests in python/grass/pygrass/vector/tests/. Each check runs in a subprocess in a GRASS session, so a crash fails one test:

• Line.to_wkb() and Area.to_wkb() release the buffer with G_free().
• The functions returning lists release each buffer with G_free().
• Calling the functions 20000 times does not leave memory allocated (glibc mallinfo2, skipped elsewhere).
• All functions return WKB of the expected size when called repeatedly. This is the case which crashes on Windows when a buffer is released with the wrong allocator.

On Linux, without the change the first, second and memory checks fail (no G_free() call, 6.1 MB left allocated after 20000 calls), and with the change all pass. The Windows crash cannot be reproduced on Linux, so the Windows job of this PR is the check for it: the last test and test_pygrass_vector_doctests.py should pass there.

Also on Linux: the pygrass vector doctests and the 7 test files in python/grass/pygrass/vector pass with grass.gunittest.main; MALLOC_CHECK_=3 reports no heap errors. clang-format, ruff check and ruff format pass.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing
  functionality to not work as before)

Checklist

• PR title provides summary of the changes and starts with one of the
  pre-defined prefixes
• My code follows the code style
  of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.

The changes were developed with the help of an AI assistant (Claude).