[postgis-devel] C-Library function returning PostGIS point crashing backend

[Mark Cave-Ayland]

On 15/01/13 03:19, David Fuhry wrote:

> Not sure if this reveals anything more, but here's the valgrind output.
> Apparently the segfault is of reading 16 bytes before the memory
> location malloced in lwgeom_to_wkb, I don't know if that's a coincidence
> or not.

Hi Dave,

Did you build your copy of PostgreSQL yourself? If you're doing any 
serious development work in C using PostgreSQL you need to build 
yourself a copy from source with the following options passed to configure:

--enable-cassert --enable-debug

Whilst not recommended for production, these options include additional 
assertion/memory checks within the binaries; in particular they add 
memory guards so that the very first time you access an unallocated 
section of memory, you'll get an immediate assertion pointing to the 
culprit rather than waiting for you to accidentally clobber an internal 
structure and cause a crash.


HTH,

Mark.