Mercurial > hg
annotate CONTRIBUTING @ 32024:ad41739c6b2b
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.
| author | Gregory Szorc <gregory.szorc@gmail.com> |
|---|---|
| date | Sun, 16 Apr 2017 11:55:08 -0700 |
| parents | a492610a2fc1 |
| children |
| rev | line source |
|---|---|
|
30084
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
1 Our full contribution guidelines are in our wiki, please see: |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
2 |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
3 https://www.mercurial-scm.org/wiki/ContributingChanges |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
4 |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
5 If you just want a checklist to follow, you can go straight to |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
6 |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
7 https://www.mercurial-scm.org/wiki/ContributingChanges#Submission_checklist |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
8 |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
9 If you can't run the entire testsuite for some reason (it can be |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
10 difficult on Windows), please at least run `contrib/check-code.py` on |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
11 any files you've modified and run `python contrib/check-commit` on any |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
12 commits you've made (for example, `python contrib/check-commit |
|
a492610a2fc1
contributing: add new file with a pointer to the wiki
Augie Fackler <augie@google.com>
parents:
diff
changeset
|
13 273ce12ad8f1` will report some style violations on a very old commit). |