bundle2: ignore errors seeking a bundle after an exception (
issue4784)
Many have seen a "stream ended unexpectedly" error. This message is
raised from changegroup.readexactly() when a read(n) operation fails
to return exactly N bytes.
I believe most occurrences of this error in the wild stem from
the code changed in this patch. Before, if bundle2's part applicator
raised an Exception when processing/applying parts, the exception
handler would attempt to iterate the remaining parts. If I/O
during this iteration failed, it would likely raise the
"stream ended unexpectedly" exception.
The problem with this approach is that if we already encountered
an I/O error iterating the bundle2 data during application, then
any further I/O would almost certainly fail. If the original stream
were closed, changegroup.readexactly() would obtain an empty
string, triggering "stream ended unexpectedly" with "got 0." This is
the error message that users would see. What's worse is that the
original I/O related exception would be lost since a new exception
would be raised. This made debugging the actual I/O failure
effectively impossible.
This patch changes the exception handler for bundle2 application to
ignore errors when seeking the underlying stream. When the underlying
error is I/O related, the seek should fail fast and the original
exception will be re-raised. The output changes in
test-http-bad-server.t demonstrate this.
When the underlying error is not I/O related and the stream can be
seeked, the old behavior is preserved.
error: rename RichIOError to PeerTransportError
This is a more descriptive name. RichIOError was introduced just
hours ago, so it doesn't need to be marked as BC.
httppeer: don't send empty Vary request header
As part of writing test-http-bad-server.t, I noticed that some
requests include an empty Vary HTTP request header.
The Vary HTTP request header indicates which headers should be taken
into account when determining if a cached response can be used. It also
accepts the special value of "*".
The previous code unconditionally added a Vary header. This could lead
to an empty header value. While I don't believe this violates the HTTP
spec, this is weird and just wastes bytes. So this patch changes
behavior to only send a Vary header when it has a value.
Some low-level wire protocol byte reporting tests changed. In some
cases, the exact point of data termination changed. However, the
behavior being tested - that clients react when the connection is
closed in the middle of an HTTP request line or header - remains
unchanged.
badserverext: explicitly flush each log write
No idea why, but without this, there was no content in the error logs that are
`cat`d in the test on Windows.
test-tag: make hook runnable on Windows
Simply setting the hook to *.sh causes Windows to open a dialog asking how to
open *.sh files.
obsolescence: add test for the "branch replacement" logic during push, case D7
Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.
This changeset adds test for the improved "branch replacement" logic introduce
in an earlier commits. This tests initially lived in the evolve extensions.
Since we now have the code handling this logic in core, it make sense to have
the tests in core too.
See inline documentation for details about the test case added in this
changeset.
obsolescence: add test for the "branch replacement" logic during push, case D5
Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.
This changeset adds test for the improved "branch replacement" logic introduce
in an earlier commits. This tests initially lived in the evolve extensions.
Since we now have the code handling this logic in core, it make sense to have
the tests in core too.
See inline documentation for details about the test case added in this
changeset.