hgweb: send proper HTTP response after uncaught exception
This patch fixes a bug where hgweb would send an incomplete HTTP
response.
If an uncaught exception is raised when hgweb is processing a request,
hgweb attempts to send a generic error response and log that exception.
The server defaults to chunked transfer coding. If an uncaught exception
occurred, it was sending the error response string / chunk properly.
However, RFC 7230 Section 4.1 mandates a 0 size last chunk be sent to
indicate end of the entity body. hgweb was failing to send this last
chunk. As a result, properly written HTTP clients would assume more data
was coming and they would likely time out waiting for another chunk to
arrive.
Mercurial's own test harness was paving over the improper HTTP behavior
by not attempting to read the response body if the status code was 500.
This incorrect workaround was added in
ba6577a19656 and has been removed
with this patch.
Create a repository:
$ hg config
defaults.backout=-d "0 0"
defaults.commit=-d "0 0"
defaults.shelve=--date "0 0"
defaults.tag=-d "0 0"
ui.slash=True
ui.interactive=False
ui.mergemarkers=detailed
ui.promptecho=True
$ hg init t
$ cd t
Make a changeset:
$ echo a > a
$ hg add a
$ hg commit -m test
This command is ancient:
$ hg history
changeset: 0:acb14030fe0a
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: test
Verify that updating to revision 0 via commands.update() works properly
$ cat <<EOF > update_to_rev0.py
> from mercurial import ui, hg, commands
> myui = ui.ui()
> repo = hg.repository(myui, path='.')
> commands.update(myui, repo, rev=0)
> EOF
$ hg up null
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ python ./update_to_rev0.py
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg identify -n
0
Poke around at hashes:
$ hg manifest --debug
b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3 644 a
$ hg cat a
a
Verify should succeed:
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
At the end...
$ cd ..