view tests/test-diff-copy-depth.t @ 33668:cde4cfeb6e3e stable

ui: restore behavior to ignore some I/O errors (issue5658)

e9646ff34d55 and 1bfb9a63b98e refactored ui methods to no longer
silently swallow some IOError instances. This is arguably the
correct thing to do. However, it had the unfortunate side-effect
of causing StdioError to bubble up to sensitive code like
transaction aborts, leading to an uncaught exceptions and failures
to e.g. roll back a transaction. This could occur when a remote
HTTP or SSH client connection dropped. The new behavior is
resulting in semi-frequent "abandonded transaction" errors on
multiple high-volume repositories at Mozilla.

This commit effectively reverts e9646ff34d55 and 1bfb9a63b98e to
restore the old behavior.

I agree with the principle that I/O errors shouldn't be ignored.
That makes this change... unfortunate. However, our hands are tied
for what to do on stable. I think the proper solution is for the
ui's behavior to be configurable (possibly via a context manager).
During critical sections like transaction rollback and abort, it
should be possible to suppress errors. But this feature would not
be appropriate on stable.

  $ for i in aaa zzz; do
  >     hg init t
  >     cd t
  > 
  >     echo
  >     echo "-- With $i"
  > 
  >     touch file
  >     hg add file
  >     hg ci -m "Add"
  > 
  >     hg cp file $i
  >     hg ci -m "a -> $i"
  > 
  >     hg cp $i other-file
  >     echo "different" >> $i
  >     hg ci -m "$i -> other-file"
  > 
  >     hg cp other-file somename
  > 
  >     echo "Status":
  >     hg st -C
  >     echo
  >     echo "Diff:"
  >     hg diff -g
  > 
  >     cd ..
  >     rm -rf t
  > done
  
  -- With aaa
  Status:
  A somename
    other-file
  
  Diff:
  diff --git a/other-file b/somename
  copy from other-file
  copy to somename
  
  -- With zzz
  Status:
  A somename
    other-file
  
  Diff:
  diff --git a/other-file b/somename
  copy from other-file
  copy to somename