This change introduces a top-level make witness target that builds a dot
graph and if graphviz is available, an SVG file as well. A shell script
replaces the previous python script that no longer works. Instead of
fixing witness.py, which is probably trivial, the shell script does an
intermediate pass and programmatically looks for cycles using tsort(1).

Checking lock dependencies becomes actionable in a CI context.

The script also takes explicit test directories on purpose, to have the
ability to aggregate test results from multiple executions. For example
when the test suite is run on various operating systems or with varying
privileges to cover feature-conditional tests.

The simple fact that Witness records might show up in the log might
break logexpect commands. There's no reason why we'd want to expect
Witness records since their purpose is to be checked after the test
finishes.

The gunzip vdp failed to handle junk after end of gzip data. This
basically mirrors #942 on the client side, also the fix is basically the
same as 41f7a356

The impact of this bug is likely to be low, because the built-in
beresp.filters logic will push the testgunzip VFP for gzip content
received from backends, so, unless VCL is forced to pass backend
responses unchecked or vmods generate body data, it can be considered
unlikely that this issue will be hit.

Fixes #3109

We use the first 64bit of a sha256 as our pool id, assuming that those
are safe enough against collisions. Ensure we do not fail on that
assumption.

This also makes it a caller error to deliberately use the same pool id
for different endpoints. As this was not possible before the id change,
I do not consider it a regression.

Ref: ec70dbc7

Ref: ec70dbc7

struct vtp_cs was only used for comparisons during pool lookup

If varnish closes the connection while a client is waiting for an
rxsomething command you may run into this kind of scenario:

    ***  c1   HTTP2 rx failed (fd:20 read: Connection reset by peer)
    ***  c1   rx: stream: 0, type: DATA (0), flags: 0x00, size: 0
    **** c1   s0 - no data
    ---- c1   Wrong frame type DATA (0) wanted SETTINGS

This was already done correctly for the frame body.

Instead of having to manually document them, we can now let the RST dump
figure everything out.

Refs #3099

Instead, they are added where they are needed: only in error messages
involving them.

Refs #3099

Refs #3108

* clarify defaults
* document Transient

Fixes #3108

Fixes: #3086

Refs #2872

Otherwise it is considered a code block instead of a paragraph where it
is used.

The VSL query could in theory do that, but I don't think it was
actionable without double quotes to delimit empty fields or fields
containing spaces.

The test case covers the last field of Backend_health records.

When we output a VSL field containing spaces, all bets are off for VSL
queries relying on that field or subsequent fields in the same record.
The solution is to allow a quoted-string format for such fields.

- fix centos:7 distcheck
- use centos to build the dist tarball
- simplify git cloning with builtin command
- no need for ssh when building
- tar the dsc files with the deb ones
- use the regular pkg repo now that the alpine PR has been merged

brought up on IRC by @scn

It is only really needed for one last use case.

Inform users when the parameter we try to change depends on another
parameter.

This is not meant to be merged as-is, we could have a new VSB function
to trim the end of the string if it matches the one passed as the second
argument. In this case, we would trim the trailing newline only of the
CLI response didn't overflow in the first place, adding the extra
information on the same line. Alternatively we could also simply add the
explanation for the dynamic bounds on the next line.

Feedback welcome.

Fixes #3098

req->err_code and req->err_reason are set when going to synthetic
handling. From there the resp.reason HTTP field is set from
req->err_reason if set, or the generic code based on req->err_code is used
if it was NULL. This patch clears these members so that a value from the
handling of a previous request doesn't linger.

Fixes: VSV00004

This de-duplicates logic between the two hashing directors, and in
the case of vmod-shard adds a missing check for empty components in
the strands that should be skipped.

This breaks the hashing of the hash director, but unlike the shard
director it offers no stability and results may vary depending on the
health of individual clusters. For this reason only d00003.vtc needed
a bit of reshuffling.

I was in the neighborhood...