[MERGE] allow recovering bad texts from knits

[Vincent Ladeuil]

>>>>> "robert" == Robert Collins <robertc at robertcollins.net> writes:

    robert> When a line delta has a bad basis - which baz imports
    robert> can create- it can be useful to be able to inspect
    robert> the result of the text delta application even when
    robert> the sha1 is wrong and it fails validation.

It looks like I encountered that precise exception (in the bug #277537 context).

    robert> This patch adds a attribute and specific exception
    robert> allowing this to be done.

So it allows recovering bad texts from knits but how do you
proceed from there ?

bzr check is still failing with a backtrace which means we get
only the first occurrence of the problem, how about the others ?

And will bzr reconcile succeeds in such cases ?

    Vincent