Merge branch 'topic/scan-build.1'

Merge branch 'topic/scan-build.1'

* topic/scan-build.1:
  colour.c: (just) (satisfy) scan-build
  mime-types.c: (just) (satisfy) scan-build
  nam-a-grp.c: (just) (satisfy) scan-build
  spam.c: (just) (satisfy) scan-build
  attachment.c: (just) (satisfy) scan-build
  cmd-misc.c: (just) (satisfy) scan-build
  cmd-write.c: (just) (satisfy) scan-build
  collect.c: (just) (satisfy) scan-build
  dotlock.c: (just) (satisfy) scan-build
  fio.c: (just) (satisfy) scan-build
  filter.c: (just) (satisfy) scan-build
  folder.c: (just) (satisfy) scan-build
  ignore.c: (just) (satisfy) scan-build
  head.c: (just) (satisfy) scan-build
  message.c: (just) (satisfy) scan-build
  mime-enc.c: (just) (satisfy) scan-build
  popen.c: (just) (satisfy) scan-build
  send.c: (just) (satisfy) scan-build
  shexp.c: (just) (satisfy) scan-build
  sendout.c: (just) (satisfy) scan-build
  strings.c: (just) (satisfy) scan-build
  tty.c: (just) (satisfy) scan-build
  mime.c: (just) (satisfy) scan-build
  obs-imap.c: (just) (satisfy) scan-build
  strings.c: tweak various old char* functions