subrepo: do not traceback on .hgsubstate parsing errors
Note that aborting in subrepo.state() prevents "repairing" commands like revert
to be issued. The user will have to edit the .hgsubstate manually (but he
probably had already otherwise this would not be failing). The same behaviour
already happens with invalid .hgsub entries.
$ hg init
$ echo "added file1" > file1
$ echo "added file2" > file2
$ hg add file1 file2
$ hg commit -m "added file1 and file2"
$ echo "changed file1" >> file1
$ hg commit -m "changed file1"
$ hg -q log
1:08a16e8e4408
0:d29c767a4b52
$ hg id
08a16e8e4408 tip
$ hg update -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg id
d29c767a4b52
$ echo "changed file1" >> file1
$ hg id
d29c767a4b52+
$ hg revert --all
reverting file1
$ hg diff
$ hg status
? file1.orig
$ hg id
d29c767a4b52
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip
$ hg update -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo "changed file1" >> file1
$ hg update
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip
$ hg revert --all
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip
$ hg revert -r tip --all
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip
$ hg update -C
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg diff
$ hg status
? file1.orig
$ hg id
08a16e8e4408 tip