WhiteFish: Detect and repair corrupted entries.
Imported from https://youtrack.roxen.com/issue/PIKE-71
Reported by @grubba
The search engine causes performance issues because of high I/O-load partly because the compactor has nut run for a long time (corrupted blobs). Re-indexing is not an option, takes too long time and the user can not search during the time. The fastest fix is probably to make the compactor handle corrupted blobs and fix them on the fly.
The search compactor exits with the following error, fix it!
Real len out of sync for word "10103"; 64 != 17
Real len out of sync for word "10107"; 128 != 28
Real len out of sync for word "10137"; 64 != 7
*** Error in `/usr/local/roxen/server-6.1.215/bin/roxen': free(): invalid next size (fast): 0x00000000025102d0 ***
======= Backtrace: =========
/lib64/libc.so.6(+0x7c619)[0x7f65e4284619]
/usr/local/roxen/server-6.1.215/pike/lib/modules/_WhiteFish.so(+0x7fc9)[0x7f65d9e56fc9]
/usr/local/roxen/server-6.1.215/pike/lib/modules/_WhiteFish.so(+0x71c5)[0x7f65d9e561c5]
...