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.
#require unix-permissions no-root
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=">> $HGRCPATH
$ teststrip() {
> hg -q up -C $1
> echo % before update $1, strip $2
> hg parents
> chmod -$3 $4
> hg strip $2 2>&1 | sed 's/\(bundle\).*/\1/' | sed 's/Permission denied.*\.hg\/store\/\(.*\)/Permission denied \.hg\/store\/\1/'
> echo % after update $1, strip $2
> chmod +$3 $4
> hg verify
> echo % journal contents
> if [ -f .hg/store/journal ]; then
> sed -e 's/\.i[^\n]*/\.i/' .hg/store/journal
> else
> echo "(no journal)"
> fi
> ls .hg/store/journal >/dev/null 2>&1 && hg recover
> ls .hg/strip-backup/* >/dev/null 2>&1 && hg unbundle -q .hg/strip-backup/*
> rm -rf .hg/strip-backup
> }
$ hg init test
$ cd test
$ echo a > a
$ hg -q ci -m "a" -A
$ echo b > b
$ hg -q ci -m "b" -A
$ echo b2 >> b
$ hg -q ci -m "b2" -A
$ echo c > c
$ hg -q ci -m "c" -A
$ teststrip 0 2 w .hg/store/data/b.i
% before update 0, strip 2
changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
saved backup bundle
transaction abort!
failed to truncate data/b.i
rollback failed - please run hg recover
strip failed, full bundle
abort: Permission denied .hg/store/data/b.i
% after update 0, strip 2
abandoned transaction found - run hg recover
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
b@?: rev 1 points to nonexistent changeset 2
(expected 1)
b@?: 736c29771fba not in manifests
warning: orphan revlog 'data/c.i'
2 files, 2 changesets, 3 total revisions
2 warnings encountered!
2 integrity errors encountered!
% journal contents
00changelog.i
00manifest.i
data/b.i
data/c.i
rolling back interrupted transaction
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 2 changesets, 2 total revisions
$ teststrip 0 2 r .hg/store/data/b.i
% before update 0, strip 2
changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
abort: Permission denied .hg/store/data/b.i
% after update 0, strip 2
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
3 files, 4 changesets, 4 total revisions
% journal contents
(no journal)
$ teststrip 0 2 w .hg/store/00manifest.i
% before update 0, strip 2
changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
saved backup bundle
transaction abort!
failed to truncate 00manifest.i
rollback failed - please run hg recover
strip failed, full bundle
abort: Permission denied .hg/store/00manifest.i
% after update 0, strip 2
abandoned transaction found - run hg recover
checking changesets
checking manifests
manifest@?: rev 2 points to nonexistent changeset 2
manifest@?: 3362547cdf64 not in changesets
manifest@?: rev 3 points to nonexistent changeset 3
manifest@?: 265a85892ecb not in changesets
crosschecking files in changesets and manifests
c@3: in manifest but not in changeset
checking files
b@?: rev 1 points to nonexistent changeset 2
(expected 1)
c@?: rev 0 points to nonexistent changeset 3
3 files, 2 changesets, 4 total revisions
1 warnings encountered!
7 integrity errors encountered!
(first damaged changeset appears to be 3)
% journal contents
00changelog.i
00manifest.i
data/b.i
data/c.i
rolling back interrupted transaction
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 2 changesets, 2 total revisions
$ cd ..