Fix some tail bugs

[mastojun]

run below script (using inotify)

let count=0; echo $count>>a.log; tail -F a.log & while true; do mv a.log a.log.$count; let count=count+1; echo $count>>a.log; done

When the number of generated file is over the "/proc/sys/fs/inotify/max_user_watches", tail can't watch new a.log file.

[mastojun]

This commit fix reported bug

[mastojun]

my test scipt is..

#!/bin/sh
prevMaxWatch=`sysctl -n fs.inotify.max_user_watches`
sudo sysctl -w fs.inotify.max_user_watches=10
d=rotatetest
mkdir $d
cd $d
timeout 20 ../tail -F k > out 2> /dev/null &

for i in $(seq 100); do
        echo ok_$i > k;
        sleep 0.01;
        env mv k k.$i
        grep ok out > /dev/null && ok=. || ok=X;
        printf $ok;
        /bin/cat /dev/null > out
done

sudo sysctl -w fs.inotify.max_user_watches=$prevMaxWatch
rm -rf $d

prev version stop ok_8 ~ ok_10. new version will be finish.
but this scipt require root authority. and if stop in running this script, max_user_watches is modified. So I don't add to test case.

[pixelb]

OK great stuff. Looking at this now.

[mastojun]

I found another bug. see 0824fcc.

if no exist file and created after run tail, work well. (used old tail_forever function)

mkdir test
cd test
prev=0
../tail --follow=descriptor k.0 &
:>k.0
sleep 2;
for i in $(seq 100); do
        env mv k.$prev k.$i;
        echo ok_$i >> k.$i;
        sleep 1;
        prev=$i
done

but exist file was wrong (use tail_forever_inotify)

mkdir test
cd test
prev=0
:>k.0
../tail --follow=descriptor k.0 &
for i in $(seq 100); do
        env mv k.$prev k.$i;
        echo ok_$i >> k.$i;
        sleep 1;
        prev=$i
done

[pixelb]

Both issues here should be addressed by: commit d313a0b and commit 235d52c