I pushed commit 030e685e. The gdbm_close function now returns int and sets both gdbm_errno and errno on error. Gdbm_sync has been changed accordingly.

Gdbm 1.15 (1.16 is also affected) changed behavior of reporting problems with database file.

The bug was discovered by perl ext/GDBM_File/t/fatal.t test. It is reported in perl bug tracker - https://rt.perl.org/Public/Bug/Display.html?id=133295#txn-1563420

In short, test actions are:
1) Perl test lets gdbm library to open a database file
2) then Perl closes a file descriptor gdbm uses for that database file
3) then Perl asks gdbm to store a key-value pair into the database
4) then Perl call gdbm_close()

The test tries to "simulate" I/O error. So old gdbm crashes in step 3) The new one finishes successfully although close() in step 4) fails with EBADF.

I know that this Perl test uses nonstandard procedure, but I/O errors could occur. And errors from msync()/fsync(), close(), flock(),... aren't currently checked, which could lead to unexpected behavior.

Or is described behavior expected? Is there any reason why gdbm_close() don't return any value?