Fix revlog-ng interaction with old-http. revlog.py wasn't trying to detect the version of a revlog file that doesn't exist on the filesystem (as is the case with old-http). Additionally, there was an off-by-one error in httprangereader.read (ranges in HTTP Range headers are inclusive), making it get more data than what was asked for. This made a struct.unpack complain that "unpack str size does not match format". Finally, with the two fixes above, test-static-http fails, since BaseHTTPServer doesn't understand ranges and returns too much data. Work around that by reading only the specified amount.

#!/bin/sh

hg init
echo foo > a
hg add a
hg commit -m "1" -d "1000000 0"
hg verify
chmod -r .hg/data/a.d
hg verify 2>/dev/null || echo verify failed
chmod +r .hg/data/a.d
hg verify 2>/dev/null || echo verify failed
chmod -w .hg/data/a.d
echo barber > a
hg commit -m "2" -d "1000000 0" 2>/dev/null || echo commit failed