tests: proof test-stdio.py against buffer fill-up
With the previous code, it could in theory happen that the pipe / PTY buffer of
the child stdout / stderr fills up and the process never finishes.
To prevent that, we read all of the stream before waiting for the end of the
process. To ensure that the stream reaches EOF when the child finishes, we must
close the parent "copy" of the child stdout / stderr.
Corrupt an hg repo with two pulls.
create one repo with a long history
$ hg init source1
$ cd source1
$ touch foo
$ hg add foo
$ for i in 1 2 3 4 5 6 7 8 9 10; do
> echo $i >> foo
> hg ci -m $i
> done
$ cd ..
create one repo with a shorter history
$ hg clone -r 0 source1 source2
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 495a0ec48aaf
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd source2
$ echo a >> foo
$ hg ci -m a
$ cd ..
create a third repo to pull both other repos into it
$ hg init corrupted
$ cd corrupted
use a hook to make the second pull start while the first one is still running
$ echo '[hooks]' >> .hg/hgrc
$ echo 'prechangegroup = sleep 5' >> .hg/hgrc
start a pull...
$ hg pull ../source1 > pull.out 2>&1 &
... and start another pull before the first one has finished
$ sleep 1
$ hg pull ../source2 2>/dev/null
pulling from ../source2
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets ca3c05af513e
(run 'hg heads' to see heads, 'hg merge' to merge)
$ cat pull.out
pulling from ../source1
requesting all changes
adding changesets
adding manifests
adding file changes
added 10 changesets with 10 changes to 1 files
new changesets 495a0ec48aaf:1e7b6c812ca8
(run 'hg update' to get a working copy)
see the result
$ wait
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 11 changesets with 11 changes to 1 files
$ cd ..