Ensure reproducible results when importing a node

[hughsie]

Do not use the address of a pointer as this breaks reproducible builds.

Fixes #110

Based on a patch by Roland Clobus rclobus@rclobus.nl, many thanks.

[hughsie]

@rclobus

[ximion]

This would work for me - and would also actually work with the existing code in AppStream :-)
Not sure though if there is any other code out there that would have a problem with it (but I doubt that).

[rclobus]

Now that a call to xb_builder_append_guid is a MUST to ensure a proper unique identifier, could you take a look at the 2 callers of xb_builder_import_node that I found in the Debian source code repository at https://codesearch.debian.net/search?q=xb_builder_import_node

@ximion appstream 0.15.0
https://github.com/ximion/appstream/blob/master/src/as-cache.c
@hughsie fwupd 1.5.7
https://github.com/fwupd/fwupd/blob/main/src/fu-engine.c

[hughsie]

fwupd 1.5.7

Yes, I checked this before merging. the tl;dr: is that fwupd does xb_builder_compile() unconditionally rather than xb_builder_ensure() and so the GUID isn't so important.

[ximion]

Same for AppStream, which has its own logic in front to rebuild the cache only if needed, so it isn't dependent on the GUID either.