In http_EstimateWS(), all headers are passed to the http_isfiltered()
function to calculate how many bytes is needed to serialize the entire
struct http. http_isfiltered() will check the headers for whether they are
going to be filtered out later and if so skip them.

However http_isfiltered() would attempt to treat all elements of struct
http as regular headers with an implicit structure. That does not hold for
the first three pseudo-header entries, which would lead to asserts in
later steps.

This patch skips the filter step for pseudo-headers.

Fixes: #3830

The vnum symbols are not exported yet, we will decide on that once we
have a case for it.

Under load, the backend connection may not be back in the pool by the
time the ESI fetch starts.

Also check the expected storage allocation failure happened.

The reason to blindly trust gethostname(3) is that a system returning a
broken host name should not prevent Varnish from starting when there is
no explicit -i option in the command line.

It disappeared from libvarnishapi during the 2.0 soname bump.

Refs 74328de8
Refs 07d4e752

> A proxy MUST send an appropriate Via header field, as described
> below, in each message that it forwards.

See rfc9110/7.6.3.

Change made to the Via header:

    -Via: 1.1 varnish (Varnish/x.y)
    +Via: 1.1 ${i_opt} (Varnish/x.y)

It should actually better serve its purpose of informing about the hops
a request (or in this case a response) went through. This is how Via is
defined in HTTP:

    Via = #( received-protocol RWS received-by [ RWS comment ] )

Using the server identity (which defaults to the server host name) is
more accurate for the received-by field. We still advertise Varnish in
the optional comment field, and hopefully that's what analytics services
rely on to recognize a server as a Varnish instance.

A bit of trivia, a proxy MAY add a Via entry to the response and MUST
add one to a forwarded request: Varnish only adds the optional one.

Refs rfc9110/7.6.3.
Fixes #3794

It can still be overridden with `varnish vNAME -arg`, as usual.

The order for Via entries follows the response return path, from the
furthest proxy to the closest.

Refs #3794

This should remove one error-prone step in the release process.

Better diff with the --word-diff --word-diff-regex='\w+' options.

Refs #3794

It works both with trunk or x.y.z versions, resulting in trunk for the
former and x.y for the latter.

Refs #3831

We have various stat counters for the shared memory log (shmlog),
but nothing to give us the number of bytes used (consumed). The
new shm_bytes counter remedies that.
Signed-off-by: Dridi Boukelmoune <dridi.boukelmoune@gmail.com>

According to the GCC manual on -fno-omit-frame-pointer:

> Note that -fno-omit-frame-pointer doesn't guarantee the frame pointer
> is used in all functions.  Several targets always omit the frame
> pointer in leaf functions.

And what is says about -m[no-]omit-leaf-frame-pointer:

> -momit-leaf-frame-pointer
> -mno-omit-leaf-frame-pointer
>
> Omit or keep the frame pointer in leaf functions.  The former behavior
> is the default.

So we should probably prevent both.

Closes #3831

Required for seamless debugging.

Alternatives considered:
- add vext_so_keep debug flag -> overkill

To decide:
- rename to libso_keep / "Keep copied VMOD/VEXT libraries" ?
  (libso to disambiguate from so for socket option)

Create a list of imports, and complain (harmlessly) if the same vmod is imported in multiple versions.

does not apply in varnish-cache, but found useful in a vmod

And rename the "check" parameter to "make_target" to avoid ambiguity.

Better diff with the --word-diff --word-diff-regex=[a-z]+ options.

And lay out the arbitrary selection rule for the sanitizer build.

And lay out the arbitrary selection rule for the 32bit build.

Everyone knows its package manager is APPX.

Manually replaced %% from printf format with %