gnucash stable: Multiple changes pushed

[John Ralls]

Updated	 via  https://github.com/Gnucash/gnucash/commit/38c1538e (commit)
	 via  https://github.com/Gnucash/gnucash/commit/035e8842 (commit)
	from  https://github.com/Gnucash/gnucash/commit/b3ef1801 (commit)



commit 38c1538e53a06ed077c738142e81029035a87624
Merge: b3ef1801b2 035e8842a0
Author: John Ralls <jralls at ceridwen.us>
Date:   Thu Nov 13 16:42:00 2025 -0800

    Merge John Ralls's 'gnc-home' into stable

commit 035e8842a0a12e78ea0ce09d880e91d9af90f003
Author: John Ralls <jralls at ceridwen.us>
Date:   Thu Nov 6 16:55:29 2025 -0800

    Protect the special environment file prefix variables.
    
    https://lists.gnucash.org/pipermail/gnucash-user/2025-November/118103.html
    reported that GnuCash crashes when he runs it with GNC_HOME=<somewhere
    random>. We use GNC_HOME to set XDG_DATA_DIR in the environment file to
    accommodate relocating GnuCash on macOS and Windows and GnuCash crashes
    when the schemas aren't found.
    
    This commit prevents the user from setting the 6 special environment
    variables either from the environment or by editing the environment file.



Summary of changes:
 libgnucash/core-utils/gnc-environment.c | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)