Commit Briefs
allow the delta base file to lose its header between deltify_init and deltify
This simplifies pack file creation. A delta base could be read from a loose object, a packfile, or it might be available in a temporary file. All these cases can now be handled the same way. We may need to open, close, and re-open a given delta base multiple times while packing.
in addblk(), only read data into buffer1 if we will compare it to buffer2
suggested by and ok naddy@
check a block's hash as well as its length before expensive comparisons
suggested by + ok naddy, and Ori agrees
fix off-by-one error in delta length; from ori
git9 commit fbb2fb7c87d8edf58e22c84f575853dc9de79ac4