Apparently, pgindent replaces multiple spaces in comments by a tab(possibly subject to additional logic). An example among thousands:
http://git.postgresql.org/gitweb?p=postgresql.git;a=blobdiff_plain;f=src/backend/access/gin/ginentrypage.c;h=c23415c0075b5ec52f08e8ef698f7b7ec2f97b19;hp=5cbbc7455519eba6c37be465784a02b350065716;hb=aa1e9bb51c102b239340992f2fcce138edb39d8a;hpb=03ee49a016e69e7594978352df6da4e0bbd7d04a
(or just rgrep -F '.<TAB>' the tree to see more).
This doesn't make any sense to me. Could this please be fixed, and ifpossible reverted sometime?