Strange output of git-diff-tree

First (noticed by matled) is that for git-diff-tree with single tree as an argument it outputs fist commit-id of commit given at input. It is not mentioned in documentation and I think totally unnecessary:

1038:jnareb@roke:~/git> git diff-tree --abbrev origin d5dc6a76d49367cddc015e01d2e9aa22e64d7e28 :040000 040000 44fb36d... 1c26294... M Documentation

Second, for some combination of options for it returns "..." instead of 0{40} for file creation. It seems that the culprit is "--find-copies-harder" option:

1043:jnareb@roke:~/git> git rev-list --full-history next | \
 git diff-tree --find-copies-harder -B -C -M -r --full-history --stdin \
 -- gitweb/gitweb.perl gitweb/gitweb.cgi gitweb.cgi | less | grep " A"
:000000 100755 ... 017664b8f440f5ec151cf5653245ee02aefd3db2 A   gitweb.cgi

1047:jnareb@roke:~/git> git rev-list --full-history next | \
 git diff-tree -B -C -M -r --stdin \
 -- gitweb/gitweb.perl gitweb/gitweb.cgi gitweb.cgi | less | grep " A"
:000000 100755 0000000000000000000000000000000000000000 017664b8f440f5ec151cf5653245ee02aefd3db2 A     gitweb.cgi

Third, while it detects that gitweb/gitweb.perl was renamed from 
gitweb/gitweb.cgi:
  [...]  R100   gitweb/gitweb.cgi       gitweb/gitweb.perl
it does not notice that gitweb/gitweb.cgi was gitweb.cgi in 
1130ef362fc8d9c3422c23f5d5a833e93d3f5c13.

All those for git version 1.4.1.1