git archive should use vendor extension in pax header

Right now, git archive creates a pax global header of the form

    comment=57ca140635bf157354124e4e4b3c8e1bde2832f1

in tar archives it creates. This is suboptimal as as comments are specified to be ignored by extraction software. It is impossible to find out in an automatic way (short of guessing) that this is supposed to be a commit hash. It would be much more useful if git created a custom key. As per POSIX suggestions, something like this would be appropriate:

    GIT.commit=57ca140635bf157354124e4e4b3c8e1bde2832f1

Please consider this suggestion.

Yours sincerely, Robert Clausecker