Fix repository corruption when using marks for modified blobs.
Fix repository corruption when using marks for modified blobs.

Apparently we did not copy the blob SHA1 into the stack variable
'sha1' when a mark is used to refer to a prior blob.  This code
was not previously tested as the Mozilla CVS -> git-fast-import
program always fed us full SHA1s for modified blobs and did not
use the mark feature there.

Signed-off-by: Shawn O. Pearce <f01032651c12a22b2103346ba96b3b6b231f9d3c@spearce.org>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git