make appendfile simpler so it does not break with revlogng on windows.
it used to cache open files. this made revlogng break because it wants
to rename files when splitting .i into .i/.d, but cannot rename or unlink
open files on windows.
new code is bit slower, but safe on linux and windows. proper fix for
too many open/close of changelog/manifest belongs in different place.
can get 10% speed improvement back.
#!/bin/sh
mkdir t
cd t
hg init
echo "added file1" > file1
echo "added file2" > file2
hg add file1 file2
hg commit -m "added file1 and file2" -d "1000000 0" -u user
echo "changed file1" >> file1
hg commit -m "changed file1" -d "1000000 0" -u user
hg -q log
hg id
hg update -C 0
hg id
echo "changed file1" >> file1
hg id
hg revert
hg diff
hg status
hg id
hg update
hg diff
hg status
hg id
hg update -C 0
echo "changed file1" >> file1
HGMERGE=merge hg update
hg diff
hg status
hg id
hg revert
hg diff
hg status
hg id
hg revert -r tip
hg diff
hg status
hg id
hg update -C
hg diff
hg status
hg id
cd ..; /bin/rm -rf t